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Summer Squash

Cucurbita pepo
Also known as: Patty Pan Squash, Scallop Squash, Scallopini

Summer Squash is a vegetable in the Cucurbitaceae family. It grows best in full sun with medium moisture, and is listed for USDA zones 2-13. Plants reach harvest about 38–98 days after planting.

Varieties

49 from High Mowing, Seeds Now & True Leaf Market · sorted by days to maturity
  • Green Machine F138–52 days

    Open habit; Harvest at 7-8"

    Resistance: IR: Cucumber Mosaic Virus; Powdery Mildew; Watermelon Mosaic Virus; Zucchini Yellow Mosaic Virus

    Aptly named for cranking out uniform fruits of exceptional quality over a long season. This vigorous variety produces nearly flawless, medium green fruits daily in the high season. With an open and upright habit for ease of harvest and disease resistances that keep plants healthy for the long haul, Green Machine F1 is consistently a top performer for commercial production. From our partners at Vitalis Organic Seeds.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Lebanese White Bush38–52 days

    Can tolerate hot temperatures; Direct sow; Grows well in full sun; Grows well with containers; Grows well with raised beds; Matures in <90 days; Start indoors; Super easy to grow

    The Lebanese Squash is a very popular heirloom squash variety that grows extremely quickly - only 45 days Very flavorful and widely grown in the Middle East A summer squash variety from Lebenon Grows as a compact bush size plant (not as a vine) Fast-growing summer squash produces large yields Perfect for growing in small spaces Days to Maturity | 45 days The Lebanese, White Squash is a favorite amongst many home gardeners. Most would recommend planting 2-4 bushes to feed a family throughout the season, while for smaller families or couples, 2 plants would be plenty. It really depends on how much squash you love to eat and whether or not you're growing other varieties at the same time. We do however recommend planting at least two plants for better pollination. The better the pollination, the better the fruit count! It's been reported that some gardeners have experienced up to 15 fruits per plant, however, that is on the high side. Most plants will produce 4-6 fruit, again depending on the pollination and other variables that come into play. There's just not an exact answer for this. You're almost at the mercy of mother nature on this, but most would agree it's a great producer! They're better picked when young and tender unless you're planning on stuffing them, then baking. In that case, they are let to grow larger, again, which will keep the plant from producing more fruit if you don't harvest regularly from them. So the bottom line is, if you want more fruit, harvest more regularly and when the squash is young and tender. This will send signals to the plant to bloom and flower again to keep reproducing. Generally, this plant will get 2-3 feet high, but regular fertilizing would, of course, alter these numbers as well. If your soil is in good condition with lots of healthy organic matter, you should have no problem getting plants that reach this size. May we suggest growing on black plastic for weed & insect control? Additional Details Though considered a vegetable in cooking, botanically speaking, squash is a fruit (being the receptacle for the plant's seeds). Squash can be served fresh (in salads) and cooked (squash stuffed with meat, fried squash, baked squash).

    View on Seeds Now
  • Round38–52 days

    Heirloom; Non-GMO; Container; Vegetable; Annual

    Cucurbita pepo Round Zucchini is a stunning plant with speckled green leaves born on a robust bush-type plant. Super fast growing and are generally eaten when they are 3-4" in diameter. Fruits go from flower to fruit in about 7-8 days. Approx. 320 seeds/ounce.

    View on True Leaf Market
  • Zucchini Cashflow Hybrid39–53 days

    Vegetable; Annual

    Resistance: HR: Zucchini Yellow Mosaic Virus

    Hybrid Zucchini Cashflow Summer Squash is ready in 46 days. This is the zucchini to grow if you have struggled with the zucchini yellow mosaic virus. Cashflow is resistant. The plant is prolific and grows in upright bushes. In our opinion, this is a perfect zucchini for those that may just want to grow 1-2 plants. You will have plenty of zucchini throughout the season.

    View on True Leaf Market
  • Zucchini Elite Hybrid39–53 days

    Vegetable; Annual

    46 days. A new virus tolerant strain which produces high yields of attractive, truly green, slightly tapered fruit with few freckles of yellow. Open areas promote ease in harvesting. Continues production of highly marketable fresh fruits later than comparable varieties. 6-7". Approx. 169 seeds/oz.

    View on True Leaf Market
  • Mexicana F140–54 days

    Open habit; Harvest at 6-8"

    Resistance: IR: Cucumber Mosaic Virus; Powdery Mildew; Papaya Ringspot Virus; Watermelon Mosaic Virus; Zucchini Yellow Mosaic Virus

    Medium grey-green fruits with small blossom ends and attractive, tapered form. Plants are single stemmed and present a very open and upright growth habit, making for easy harvests. Skin and flesh are tender with a delightful nutty flavor, and plants are highly productive long into the growing season.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Supersonic F141–55 days

    Multipik type; Yellow straightneck; Harvest at 5-6”

    Extra-early, yellow straightneck squash with high yields and continuous fruit set. Plants are single-stem, with an open growth habit making them very easy to pick, and they exhibit the precocious yellow gene, a trait that shows up as a yellow stem on the fruit. This gene has shown evidence of the early development of color on baby fruit and limiting greening of mature fruit caused by cucumber mosaic virus and watermelon mosaic virus, increasing the harvest window. Bred by our partners at Seneca Vegetable Research. A portion of the sales of this variety is paid to the breeder. Costata Romanesco Dario F1 Midnight Lightning Dark Star Cocozelle Supersonic F1

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Dark Green42–58 days

    Harvest at 6-8”

    Vigorous variety produces good yields of straight, smooth fruits. An open- pollinated variety best suited to the home garden with abundant yields of lightly mottled dark green fruits. Pale greenish-white, firm flesh.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Desert F142–58 days

    Drought tolerant; Harvest at 7-8”

    Resistance: IR: Cucumber Mosaic Virus; Powdery Mildew; Papaya Ringspot Virus; Watermelon Mosaic Virus; Zucchini Yellow Mosaic Virus

    Gorgeous fruits with strong disease resistance and exceptional fruit set in hot weather. Dark green fruit with slight speckles are cylindrical and very attractive. Tall plants have a broad, open architecture which makes for easy picking. Impressive resistance to powdery mildew in our trials. Sister variety to Dunja F1

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Dunja F142–58 days

    Compact habit; Short spines; Harvest at 7-8”

    Resistance: IR: Powdery Mildew; Papaya Ringspot Virus; Watermelon Mosaic Virus; Zucchini Yellow Mosaic Virus

    Excellent disease resistance and high yields of attractive, straight, green glossy fruit. A true standout. When compared to market standards like Payroll F1, Dunja F1 outperformed them in powdery mildew resistance and overall yield. Plants are compact and single-stemmed with short spines.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Garden Spineless Zucchini Hybrid42–58 days

    Vegetable; Annual

    50 days to maturity. Cucurbita pepo. Garden Spineless Zucchini Hybrid Summer Squash Seeds. Non-GMO, annual, hybrid. This is suitable for growing in fields, garden plots, raised beds, and containers. Nearly spineless, open plants make painless harvesting of glossy, dark green zucchinis easy; tender, mild flavor shines grilled or sautéed, and frequent picking boosts yields. ~250 seeds/oz.

    View on True Leaf Market
  • Goldy F142–58 days

    Resists greening; Open habit; Harvest at 8-10”

    Resistance: IR: Powdery Mildew

    Long, slender fruits with bright yellow skin, white flesh and contrasting green stems. Open habit with few spines makes harvesting easy. Heavy yields with a high percentage of marketable fruit. Mix with green zucchini for an eye-catching display. Similar to Sebring and Gold Rush, with less greening than Gold Rush. From our partners at Genesis Seeds.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Ladoga F142–58 days

    Semi-spineless plants; Harvest at 6-8”

    Resistance: IR: Papaya Ringspot Virus; Watermelon Mosaic Virus; Zucchini Yellow Mosaic Virus

    High yields of dark green, glossy fruit on semi-spineless, upright plants. Plants are vigorous and very productive and have excellent staying power in the field. Uniform fruits are set high on vertical plant centers. The single stem, open plants, and small spines make for an easy and efficient harvest. From our partners at Bejo Seeds.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Smooth Operator F142–58 days

    Loy's Choice™; Spineless; Harvest at 6-7"

    Resistance: HR: Powdery Mildew

    An elegant summer squash you can pick without pain. Get ready for your easiest harvests ever: Smooth Operator F1 is highly refined both in plant architecture and smoothness. Upright, open habit plants are easy to access, quick to pick, and yield a gorgeous crop of long, slim fruit with very smooth skin. Part of the Slick Pik® series carrying the gl-2 glabrous gene developed by Dr. Brent Loy at the University of New Hampshire. A portion of the sales of this variety is paid to the breeder.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Success PM Straightneck42–58 days

    Uniform shape; Harvest at 6-7”

    Resistance: HR: Powdery Mildew

    Prolific, disease-resistant plants with smooth, uniform and attractive fruit. A breakthrough in open-pollinated summer squash; high yielding in our trials with over three months of abundant, disease-free harvest. Released by High Mowing and Cornell’s Vegetable Breeding Institute. A portion of the sales of this variety is paid to the breeder.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Yellow Crookneck42–58 days

    Prolific yields; Harvest at 5-6”

    Tender, lemon-yellow fruits. Signature bent fruit are best harvested at 5-6” long or smaller for best flavor and texture. Our strain has been selected for yield, shape and quality. If left to overgrow, can be used for a dark yellow, warty ornamental gourd.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Yellowfin F142–58 days

    Compact, open habit; Harvest at 6-8”

    Resistance: IR: Cucumber Mosaic Virus; Powdery Mildew

    Uniform, cylindrical fruits with bright yellow coloration. Pure golden fruits with buttery flavor simply glow at market. Compact, nearly spineless plants have an open habit for ease of harvest. Intermediate resistance to cucumber mosaic virus and powdery mildew for a reliable harvest, even in challenging field conditions. From Vitalis Organic Seeds.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Zucchini Greyzinni Hybrid42–58 days

    Vegetable; Annual

    50 days. High-yielding, 5 to 6 inch, attractive heavily striped, light green-grey zucchini with fine eating quality and creamy, sweet flavor. These somewhat blocky fruits have a slight taper. Open-spaced plants support easy harvesting and bears over a long season. Ideal for any dish - savory or sweet. Approx. 195 seeds/oz.

    View on True Leaf Market
  • Benning’s Green Tint44–60 days

    Patty pan-type; Harvest at 3-4” diameter

    Prolific patty pan with striking, pale green fruits that mature to a creamy-white. Bush habit of plants provides good coverage for dense clusters of scalloped-edge fruits. Listed on the Slow Food Ark of Taste as a distinctive food facing extinction. Excellent flavor profile when sautéed or stuffed, and a beautiful addition to squash mixes for market or kitchen harvests.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Costata Romanesco Zucchini44–60 days

    Container; Vegetable; Annual

    Cucurbita pepo (52 days) A sought-after Italian heirloom grown around Rome for years. The zucchini is grey-green, has fluted edges or ribs. When cut these fluted edges give them a scalloped appearance. The flavor is very rich and nutty. Unique amongst summer squash. Much better taste than hybrids.

    View on True Leaf Market
  • Ronde de Nice44–60 days

    Specialty crop; Harvest at 3-4” diameter

    Perfectly spherical light green fruits with white speckling—a unique specialty item. Heirloom from southern France with nice nutty flavor and great texture for fresh eating or freezing. Round shape and small size make this variety perfect for stuffing.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Stardust44–60 days

    Productive; Variegated leaves; Harvest at 6-9"

    Large, productive plants with beautiful, medium to dark green fruit. One of our most uniform open-pollinated zucchinis in fruit shape and color, plants produce abundantly on short stems. Leaves are large and variegated and fruit are covered in beautiful tiny flecks of contrasting color with defined, attractive ridges.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Dark Green Zucchini (Organic)45–65 days

    Heirloom; Organic; Container; Vegetable; Annual

    Cucurbita pepo. (45-65 days) An early vigorous bush zucchini with straight, smooth, dark-green mottled fruits. Tastiest at 6-8" with pale greenish-white, firm flesh. Great for market growers and easy to grow. Very prolific with heavy yields. You will be giving it away to everyone you know. We do, then we make zucchini bread...YUM. Zucchinis contain useful amounts of folate (24 mcg/100 g), potassium (280 mg/100 g) and vitamin A (384 IU [115 mcg]/100 g).

    View on True Leaf Market
  • Golden Glory Hybrid45–61 days

    Vegetable; Annual

    53 days. The 7 to 8 inch, 2-3" in diameter, smooth, waxy-skinned, gold fruits have creamy white, excellent tasting flesh. The vigorous open plant bears fruit of superior quality and uniformity. Spreads between 36-72". Yields exceptional crops. This strain has been noted for its ability to set fruit in the complete absence of pollen for excellent yield potential even in low pollen conditions. Approx. 200 seeds/oz.

    View on True Leaf Market
  • Zucchini Grey45–50 days

    Heirloom; Container; Vegetable; Annual

    45-50 days. Zucchini Grey Summer Squash Seeds. Cucurbita pepo. Non-GMO. Open Pollinated. An Old World heirloom native to Italy, the Zucchini Grey summer squash has been a Mediterranean favorite since the early 1800s. Since then, Zucchini Grey squash seeds have lent itself to numerous seasonal hybrids and cultivars of Italian summer squash. Unlike plain green varieties of squash seeds, Zucchini Grey boasts a uniquely striped skin very similar to a Greyzinni hybrid. Approx 258 seeds/oz.

    View on True Leaf Market
  • Costata Romanesco46–62 days

    Gourmet variety; Harvest at 6”

    Wins every taste test with its unique, slightly nutty flavor and exceptional texture. Italian heirloom with tender, gray-green skin and prominent ribbing that give this variety a distinctive appearance. Pick at 6” or smaller and fry whole with the flower still attached. Unavailable in 2024

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Early White Bush Scallop46–62 days

    Heirloom; Vegetable; Annual

    Early White Bush Scallop is a summer patty pan squash ready in about 54 days. The flattened, scalloped fruits are pale green when young and ripen to creamy white. For the most tender eating, harvest while small, about 2 to 4 inches across. The plants form a compact bush rather than a sprawling vine, making them a good choice for gardeners with limited space.

    View on True Leaf Market
  • Dario F147–63 days

    Cocozelle-type; Upright, single stemmed; Harvest at 10-12”

    Resistance: HR: Powdery Mildew

    Improved with more defined striping, open plant habit, disease resistance and attractive fruit. Eye-catching variety with lime-green stripes won us over in our trials with long, slender fruit that hold well after harvest. Open habit for easier picking. Sweeter flavor than most Cocozelle types. From our partners at Genesis Seeds.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Dark Star47–63 days

    Drought tolerant for dry farming; Uniform; Harvest at 6-8”

    Stellar variety selected for drought tolerance, high-quality uniform fruit and high yields. Dark green, glossy fruit on single-stemmed plants with great vigor. Bred for productive plants that establish easily without irrigation. Modern open-pollinated variety developed by Organic Seed Alliance and Eel River Produce in Humboldt County, CA.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Midnight Lightning47–63 days

    OSSI; BRED BY HIGH MOWING; PM tolerant; Harvest at 7-8”

    Extra-long and slender zucchini with dark green, almost-black coloring. Single-stemmed plants are sturdy and stems have few spines. Plants produce quickly and have good field resistance to disease. The first variety developed on our organic seed farm in Wolcott, Vermont and released through the Open Source Seed Initiative.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Y-Star F147–63 days

    Patty pan-type; Prolific; Harvest at 2-4” diameter

    Golden saucer-shaped fruits with attractive, scalloped edges. Plants begin producing early and remain prolific throughout the season. Excellent flavor; harvest when small and tender, about the size of a teacup.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Zucchini Eight Ball Hybrid47–63 days

    AAS Winner; Container; Vegetable; Annual

    55 days. AAS Winner for 1999. The first round summer squash. Dark zucchini skin with a unique round shape, somewhat lighter green streaks, smooth and shiny skin with great buttery taste. Commonly used for stuffing edible, savory foods into its cavities. Improved for earliness. Can be harvested in about 5 to 6 weeks. Plants grow to 3 feet wide. Approx. 189 seeds/oz.

    View on True Leaf Market
  • Zucchini Italian Striped47–63 days

    Heirloom; Vegetable; Annual

    55 days. Also known as Cocozelle Zuccini. Traditional Italian favorite often harvested extra early, but still very good when left to a larger size. Appealing dark green with lighter broad stripes; excellent flavor. Will grow up to 12" long. Not actually a true zucchini, this summer squash has a slightly larger blossom end.

    View on True Leaf Market
  • Zucchini, Endurance BC, F148–55 days

    Vegetable; Annual

    Summer Squash, Endurance BC-2 F1. Cucurbita pepo. AKA: Zucchini. Squashes started showing up in Italian kitchens as early as 1600, the "Zucchini" variety probably originated around 1850. Extremely productive, and very easy to harvest, makes many smooth light green oblong fruits.

    View on True Leaf Market
  • Cocozelle49–67 days

    Bush habit; Uniform shape; Harvest at 6-8”

    Productive, tasty Italian variety with attractively striped fruits. Dark and light green striping is less defined than Costata Romanesco. Flavor is slightly nutty; milder than Costata but more flavorful than most zucchini. Straight fruit with very slight ribbing over the lighter green striping.

    Growing notes: Days to maturity are from direct seeding, subtract two weeks if transplanting. Summer squash are warm-season annuals in the cucurbit family, which includes winter squash, pumpkins, watermelons, cucumbers and melons. Direct seed as soon as all chance of frost has passed or start transplants 3-4 weeks before planting date. Optimum soil temperature for germination is about 85ºF. Black plastic mulch and floating row cover can be used to increase soil and air temperature, as well as ward off cucumber beetles which feast on young seedlings and spread disease. Many growers plant multiple successions of summer squash during a season to ensure continuous harvest, transplanting the first succession immediately after last frost date and the final succession three months before the expected first frost. Best quality fruit are harvested at 5–8” or smaller, while skin is soft and somewhat glossy. Harvest fruits every other day for best size and quality and to maintain plants’ productivity. Fruits are easily bruised and very perishable, but will store 1 to 2 weeks at 41-50ºF with 90% relative humidity.

    View on High Mowing
  • Crookneck (Organic)49–67 days

    Heirloom; Organic; Container; Vegetable; Annual

    Ready in about 58 days, Organic Summer Crookneck Squash is perfect for the summer garden. Bumpy skin highlights a yellow fleshy squash. When the fruit is 5-6 inches long, it should be harvested. This squash is perfect for eating with its buttery-sweet taste. Crookneck squash offers continuous squash yield.

    View on True Leaf Market
  • Black Beauty Zucchini50–60 days

    Can tolerate hot temperatures; Direct sow; Grows well in full sun; Grows well with raised beds; Start indoors; Super easy to grow

    An All America Selections (AAS) Winner. The Black Beauty Squash is one of the most popular varieties on the market - Grows as a compact bush (not as a vine) - Produces a dark green, glossy fruit, which is long, straight & slender - Firm, very tender, with excellent flavor - Easy to grow Days to Maturity | 110 days Additional Details Though considered a vegetable in cooking, botanically speaking, squash is a fruit (being the receptacle for the plant's seeds). Squash can be served fresh (in salads) and cooked (squash stuffed with meat, fried squash, baked squash). Follow SeedsNow.com's board Zucchini Recipes on Pinterest.

    View on Seeds Now
  • Cocozelle Zucchini50–60 days

    Heirloom; Container; Vegetable; Annual

    50-60 Days to maturity. Cucurbita pepo. Cocozelle Zucchini Seeds. Non-GMO, annual, open-pollinated, heirloom. Suitable for growing in garden plots, raised beds, and containers. A traditional Italian heirloom introduced in the late 1800s, Cocozelle produces cylindrical, dark green fruits with lighter green stripes. Tender flesh, excellent flavor, and prolific yields make it a garden favorite. Best harvested young for best eating quality. Blooms are great beer-battered and fried. Remember to keep them picked at about the size of a large cucumber, and they will continue to produce. ~260 seeds/oz.

    View on True Leaf Market
  • Crookneck50–60 days

    Heirloom; Container; Vegetable; Annual

    50-60 days. Crookneck Summer Squash Seeds. Cucurbita pepo. Non-GMO. Open Pollinated. Non-GMO Summer Crookneck squash is ready in about 58 days. The flesh of this squash is bumpy and yellow. The fruit is best harvested when it is 5-6" long. Known as an excellent eating squash, the Crookneck is buttery and sweet. Squash does have crookneck and offers a continuous yield on the vine. This is a delicious yellow squash variety for your garden. Approx 362 seeds/oz.

    View on True Leaf Market
  • Early Prolific Straightneck50–60 days

    Heirloom; AAS Winner; Container; Vegetable; Annual

    50-60 days. Early Prolific Straightneck Summer Squash Seeds. Cucurbita pepo. Non-GMO. Open Pollinated. Non-GMO Early Prolific Staightneck Summer Squash is ready to harvest from the vine after 52 days. Early Prolific debuted as the 1938 AAS Vegetable Winner for uniform yellow squash best harvested when 7" long. This is a very popular heirloom variety due to its buttery, nutty flavor, and tireless production. Plus, it's both early and prolific. Approx 313 seeds/oz.

    View on True Leaf Market
  • Fordhook Zucchini50–60 days

    Heirloom; AAS Winner; Container; Vegetable; Annual

    Resistance: HR: Powdery Mildew

    50-60 Days to maturity. Cucurbita pepo. Fordhook Summer Zucchini Seeds. Non-GMO, annual, open-pollinated, heirloom. 1942 AAS winner. Suitable for growing in fields, garden plots, raised beds, and greenhouses. Resistant to powdery mildew. Known for its reliable production of dark green, tender, straight fruits that are perfect for grilling, sautéing, or baking. ~175 seeds/oz.

    View on True Leaf Market
  • Fordhook Zucchini (Organic)50–60 days

    Heirloom; Organic; AAS Winner; Container; Vegetable; Annual

    50 to 60 days to maturity. Cucurbita pepo. Organic Fordhook Zucchini Summer Squash Seeds. Non-GMO, annual, heirloom, open-pollinated, organic. This is suitable for fields, garden plots, raised beds, and containers. Classic dark-green zucchini known for its uniform, straight fruits, vigorous production, and tender, mild flavor. Excellent for grilling, sautéing, baking, and freezing. ~230 seeds/oz.

    View on True Leaf Market
  • Caserta55–75 days

    Can tolerate hot temperatures; Direct sow; Grows well in full sun; Grows well with containers; Grows well with raised beds; Matures in <90 days; Start indoors; Super easy to grow

    A 1949 All-America Selections Winner Grows as a bush Produces high yields of 16" long grayish-green zucchini squash with dark green stripes Perfect for home garden and market growers. Days to Maturity | 65 days Additional Details Though considered a vegetable in cooking, botanically speaking, squash is a fruit (being the receptacle for the plant's seeds). Squash can be served fresh (in salads) and cooked (squash stuffed with meat, fried squash, baked squash).

    View on Seeds Now
  • Scallop, Golden Bush55–75 days

    Can tolerate hot temperatures; Direct sow; Grows well in full sun; Grows well with containers; Grows well with raised beds; Matures in <90 days; Start indoors; Super easy to grow

    One of the most popular and rare heirloom Squash varieties Grows as a compact bush size plant (not as a vine) Produces 4-5" golden-yellow fruits Grow well in small spaces These plants grow continuously over a long season Days to Maturity | 65 days Additional Details Though considered a vegetable in cooking, botanically speaking, squash is a fruit (being the receptacle for the plant's seeds). Squash can be served fresh (in salads) and cooked (squash stuffed with meat, fried squash, baked squash).

    View on Seeds Now
  • Zucchini Golden55–65 days

    Heirloom; Container; Vegetable; Annual

    55-65 days. Golden Zucchini Summer Squash Seeds. Cucurbita pepo. Annual. Open Pollinated. Non-GMO Heirloom Golden Zucchini is the summer squash to grow in the garden. it's ready in 55 days and beginner-friendly. Not as productive as green varieties, but beautiful golden yellow fruits make it all worth it. Plus, Golden Zucchini is easy to spot under all the greenery. Pick this variety at 6-8" long for the best taste. Zucchini is a crop that produces all summer until frost. Approx 258 seeds/oz.

    View on True Leaf Market
  • Zucchini Black Beauty60–70 days

    Heirloom; Vegetable; Annual; Container; AAS Winner

    60-70 days. Black Beauty Zucchini Summer Squash Seeds. Cucurbita pepo. Non-GMO. Open Pollinated. AKA: Courgette. One of the most productive crops to ever find its way into the home garden, Black Beauty zucchini summer squash seeds will produce vigorously well up until the frost. Harvest Black Beauty zucchini often as fruits are most tender and delicious when about 6-8", but seeds quickly produce 18-24" long zucchini if left out in the garden even for a few extra days. Approx 242 seeds/oz.

    View on True Leaf Market
  • Zucchini Black Beauty (Organic)60–70 days

    Heirloom / Open Pollinated; Vegetable; Annual; Container; Organic; AAS Winner

    60-70 days. Organic Black Beauty Zucchini Summer Squash Seeds. Cucurbita pepo. Non-GMO. Organic. AKA: Courgette. One of the most productive crops to ever find its way into the home garden, Organic Black Beauty zucchini summer squash seeds will produce vigorously well up until the frost. Harvest Black Beauty zucchini often as fruits are most tender and delicious when about 6-8", but seeds quickly grow 18-24" long if left in the garden even for a few extra days. Approx 215 seeds/oz.

    View on True Leaf Market
  • Marrow, Green72–98 days

    Can tolerate hot temperatures; Direct sow; Grows well in full sun; Grows well with containers; Grows well with raised beds; Matures in <90 days; Start indoors; Super easy to grow

    The Green Marrow Summer Squash produces some of the most beautiful looking dark green squash Grows as a compact bush (not as a vine) Best when picked at 8" long Perfect for small gardens - grows on a compact bush Days to Maturity | 85 days Additional Details Though considered a vegetable in cooking, botanically speaking, squash is a fruit (being the receptacle for the plant's seeds). Squash can be served fresh (in salads) and cooked (squash stuffed with meat, fried squash, baked squash).

    View on Seeds Now
  • Marrow, White72–98 days

    Can tolerate hot temperatures; Direct sow; Grows well in full sun; Grows well with containers; Grows well with raised beds; Start indoors; Super easy to grow

    The White Marrow Summer Squash produces some of the most beautiful looking snow white squash - Grows as a compact vine (not as a bush) - Best when picked at 8" long - Perfect for small gardens, containers, and raised beds Days to Maturity | 85 days Best Months to Plant | [March - June] Summer squash love the sun and can't get enough of it. They are warm-season crops and are sensitive to cold/frost. Plant your seeds as soon as the soil has warmed. Additional Details Though considered a vegetable in cooking, botanically speaking, squash is a fruit (being the receptacle for the plant's seeds). Squash can be served fresh (in salads) and cooked (squash stuffed with meat, fried squash, baked squash).

    View on Seeds Now
Family
Cucurbitaceae
Category
Vegetable
Form
Bush
Lifecycle
annual
Zone
2-13
Height
1–2.5 ft
Spread
2–6 ft
Sun
Full sun
Water
Medium

Plan your summer squash planting

Add summer squash to a free GardenDraft plan and get sow, transplant, and harvest dates computed for your ZIP code — with a drag-and-drop bed layout and reminders when it’s time to plant.

Start your free plan →

At a glance

Days to harvest
38–98 days
From transplant or sow to first harvest
Harvest style
Keep picking
Crops over several weeks
After harvest
Use right away
Quality drops fast past peak
Frost tolerance
Tender · to ~32°F
Lowest temperature the foliage usually survives
Germination
~75%
Typical minimum germination rate

Storing & preserving

Best used right away — quality drops fast. Refrigerate and use within days — a classic glut crop.

  • Freeze: Shred and freeze for breads and soups (drain after thawing).

General home-preservation guidance — for tested processing times and safety, follow the National Center for Home Food Preservation.

Growing timeline

When to plant and harvest summer squashPlanting timeline for summer squash, relative to last frost: start indoors from 3 weeks before last frost to 1 week after last frost; grow from 1 week after last frost to 6 weeks after last frost; harvest from 6 weeks after last frost to 15 weeks after last frost.Start indoorsGrowHarvestLast frostTransplant
Start summer squash indoors ~4 weeks before transplanting 1 week after last frost; first harvest 6 weeks after last frost.
Seed to transplant
21-28 days
Outdoor planting
7 to 14 days vs frost
Propagation
Seed
Schedule anchor
Last Frost

Companion planting — with cited sources

From US/Canada cooperative-extension publications and peer-reviewed studies. Evidence-tier dots show how strongly each recommendation is backed: ●●● peer-reviewed mechanism · ●● extension consensus · traditional knowledge with a plausible mechanism.

Pairs well with (3)

  • Common BeanEvidence tier B: Extension consensus across multiple US/Canada land-grant institutionsn-fixation

    Bush beans interplanted between summer squash hills contribute modest in-season N from nodule turnover and post-season N from residue breakdown. Documented in Cornell, MSU, and Penn State home-garden guides.

    Source: S1, S5, Penn State Extension

  • Runner BeanEvidence tier B: Extension consensus across multiple US/Canada land-grant institutionsweed-suppression, moisture-conservation

    Runner bean and squash polyculture (with or without corn) is documented in Cornell and West Virginia extension guides; squash provides living mulch and runner bean contributes N to subsequent crops.

    Source: S1

  • Common NasturtiumEvidence tier C: Traditional practice with plausible mechanism but limited empirical replicationpest-deter

    Nasturtium intercropped with summer squash is reported by Agriculture Canada and several universities to alter squash bug oviposition site preference, reducing egg masses on squash leaves. The effect is partial; nasturtium does not eliminate squash bug pressure but can reduce damage when combined with other measures.

    Source: SARE, Agriculture and Agri-Food Canada

Avoid planting near (2)

  • Common CucumberEvidence tier B: Extension consensus across multiple US/Canada land-grant institutionsdisease-host, alternate-host-pest

    All cucurbits share pest and disease complexes (cucumber beetle, squash bug, vine borer, downy and powdery mildew, bacterial wilt).

    Source: S1, S7

  • Common PotatoEvidence tier C: Traditional practice with plausible mechanism but limited empirical replicationdisease-host

    Shared susceptibility to Verticillium and Fusarium. Extension rotation guidance separates cucurbits and Solanaceae into distinct rotation groups.

    Source: S1

Trap crops for this plant (3)

  • Blue Hubbard SquashEvidence tier A: Peer-reviewed studies in US/Canada production conditions with a clear mechanismtrap-crop

    Perimeter Blue Hubbard (C. maxima) intercepts 65-90% of cucumber beetles and 90% of squash bugs in summer squash field trials at UVM and USDA-ARS, allowing border-only insecticide management.

    Timing: Plant trap 1-2 weeks before cash crop.

    Region: Northeast and Midwest US.

    Source: University of Vermont Extension, USDA ARS

  • Common RadishEvidence tier B: Extension consensus across multiple US/Canada land-grant institutionstrap-crop

    Radish acts as a partial trap/alternate-host for cucumber beetle when interplanted at squash emergence.

    Source: SARE

  • DaikonEvidence tier C: Traditional practice with plausible mechanism but limited empirical replicationtrap-crop

    Same striped cucumber beetle deterrence cited for common radish; see common radish.

    Source: University of Maryland Extension

Sources cited

S1
Cornell University Cooperative Extension — vegetable production guides
S14
University of Vermont Extension
S18
SARE (Sustainable Agriculture Research and Education)
S20
USDA ARS (Agricultural Research Service) publications
S25
Agriculture and Agri-Food Canada
S5
Michigan State University Extension
S6
Penn State Extension
S7
University of Minnesota Extension
S9
University of Maryland Extension — Home & Garden Info Center

Care & troubleshooting— extension-sourced, with citations

When to feed, prune & water

Attract beneficial insects and protect pollinators

Protection
  • Routine carePlant insectary flowers and tolerate light pestsstrong evidence — extension confidence

    Grow a diversity of flowering plants (including small-flowered umbels and asters) to feed predators and parasitoids, and tolerate low pest numbers so natural enemies have prey to stick around.

    Source: UC IPM; UMN Extension

  • Routine careNever spray open bloomsstrong evidence — extension confidence

    Avoid insecticides on flowering plants and apply any needed sprays in the evening when pollinators aren't active, and favor selective products over broad-spectrum ones to spare bees and beneficials.

    Source: UC IPM

Mulch and water the squash family

Watering
  • Routine careDeep weekly watering· every 1 wk · ~12 wksstrong evidence — extension confidence

    Cucurbits are thirsty and shallow-rooted. Water deeply about weekly (more in heat), at the base to keep foliage dry and slow mildew.

    Source: UC ANR

  • Routine careMulch to hold moisturemoderate evidence — extension confidence

    Lay straw or leaf mulch once established to even out soil moisture, suppress weeds, and keep fruit off bare soil.

    Source: UC ANR

Plan crop rotation

Rotation
  • Routine careRotate plant families between bedsstrong evidence — extension confidence

    Avoid planting the same family in the same bed in consecutive years (aim for a 3+ year gap), grouping crops by family so soilborne diseases and pests that build up don't carry over to the next susceptible crop.

    Source: UMN Extension; Cornell

  • Routine careSequence for soil healthmoderate evidence — extension confidence

    Follow heavy feeders like tomatoes and brassicas with legumes or a cover crop to support soil fertility and structure, and keep simple notes each year so you can track where each family grew.

    Source: UMN Extension

Protect the garden from deer

Protection
  • Routine careFence the gardenstrong evidence — extension confidence

    A fence about 8 feet tall and tight to the ground is the most reliable barrier; an outward-angled or double fence, or monofilament line strung at 30 to 36 inches, can also deter deer on smaller beds.

    Source: UMN Extension; Cornell CCE

  • Routine careRotate repellents as a supplement· every 2 wksmoderate evidence — extension confidence

    Where fencing isn't feasible, apply odor/taste repellents and alternate formulations, reapplying every couple of weeks and after rain; combining repellents with fencing works best.

    Source: UMN Extension; PennState Extension

Water deeply at fruiting

Watering
  • Routine careProvide steady deep watering during fruiting· every 3 daysstrong evidence — extension confidence

    Once plants begin flowering and setting fruit, supply about 1 to 1.5 inches of water per week in deep soakings rather than light sprinkles, ideally at the base; even moisture reduces cracking, blossom-end rot, and bitter or misshapen fruit.

    Source: UMN Extension: Tomato disorders; UMN Extension: Growing tomatoes

Clean up debris and sanitize at season end

Sanitation

Unusual this time of year.

  • Routine careRemove spent plants and fallen debrisstrong evidence — extension confidence

    Pull and clear old plants, dropped fruit, and leaf litter at season end, since many pests and diseases overwinter in this debris; dispose of diseased material rather than composting it.

    Source: UMN Extension; Cornell

  • Routine careClean tools, stakes, and cagesmoderate evidence — extension confidence

    Wash and sanitize stakes, cages, and tools that touched diseased plants before storing or reusing them to avoid carrying pathogens into next season.

    Source: Cornell; UMN Extension

Cutworm collars at transplant

Protection

Unusual this time of year.

  • Routine careSet a collar around each new transplantstrong evidence — extension confidence

    When setting out transplants, slip a collar (a toilet-paper tube, paper cup with the bottom cut out, or similar) around each stem and press it a couple inches into the soil so it stands a few inches above ground, blocking cutworms from the stem.

    Source: UMN Extension: Cutworms; UC IPM: Cutworms

Floating row cover timing

Protection

Unusual this time of year.

Harden off seedlings

Protection

Unusual this time of year.

Read: starting seeds indoors

Trellis vining crops

Support

Unusual this time of year.

Something looks wrong?

Describe what you see on your summer squashand we'll rank the likely causes — most likely first, least-invasive fix first.

Cucurbit bacterial wilt

Diseasesevere

Symptoms: sudden wilting of individual leaves then whole vines; wilt with no yellowing at first; plants collapse despite moist soil; cut stem oozes sticky sap that strings out; cucumber beetles present

Gummy Stem Blight / Black Rot (Cucurbits)

Diseasesevere

Symptoms: water-soaked stem cankers; amber gummy ooze on stems; tan-to-dark circular leaf lesions with concentric rings; black speck-like fruiting bodies; black rot of fruit

  • CulturalRotate, sanitize, and use clean seedstrong evidence — extension confidence

    Use disease-free seed and rotate at least 2 years away from cucurbits, removing and destroying infected vines and fruit since the fungus survives in debris and seed. This is a prevention/management problem, not a cure.

    Source: UMN Extension; Cornell LIHREC

  • CulturalKeep foliage drystrong evidence — extension confidence

    Switch to drip irrigation and space plants for airflow so leaves dry quickly, since free moisture drives infection.

    Source: UMN Extension; UF/IFAS

Phytophthora blight (root and crown rot)

Diseasesevere

Symptoms: sudden wilting and collapse of peppers or squash; dark water-soaked lesions at the crown or stem base; white cottony growth on infected fruit; root and crown rot; vine and fruit rot after heavy rain or in wet low spots

  • CulturalRemove affected plants at first sign (manage, not cure)strong evidence — extension confidence

    Infected plants can't be saved; promptly pull and destroy them at the start of an outbreak to slow spread, and avoid working in beds when wet.

    Source: Cornell Vegetables; UMN Extension

  • CulturalImprove drainage and avoid waterloggingstrong evidence — extension confidence

    Plant on raised beds, never let beds stay saturated, and water with drip rather than flooding, since this water mold thrives in standing water and saturated soil.

    Source: Cornell Vegetables; UMN Extension

  • CulturalRotate and choose tolerant varietiesmoderate evidence — extension confidence

    Rotate out of peppers, cucurbits, and tomatoes for at least three years where the disease has occurred, and select tolerant or resistant varieties when available.

    Source: Cornell Vegetables

Phytophthora Fruit & Crown Rot (Cucurbits)

Diseasesevere

Symptoms: sudden wilt and crown collapse; soft water-soaked rot at the crown; large tan-to-salmon soft spots on fruit; white yeast-like mold on rotting fruit; plants dying in wet low spots

  • CulturalImprove drainage and avoid waterloggingstrong evidence — extension confidence

    Plant on raised, well-drained beds, avoid low wet spots, and lengthen intervals between irrigations, since this water mold thrives in saturated soil. Once established it is very hard to control, so prevention is key.

    Source: UC IPM; Clemson Extension

  • CulturalRotate and avoid infested fieldsstrong evidence — extension confidence

    Avoid sites with a Phytophthora history and rotate to non-host crops (avoid cucurbits, peppers, tomato, eggplant), since the oospores survive in soil for years.

    Source: Clemson Extension; OSU Extension

  • ChemicalApply oomycete-targeted fungicide preventively· every 1 wkmoderate evidence — extension confidence

    As part of an integrated program, apply an oomycete-active fungicide (e.g., mefenoxam or phosphonate class) preventively before wet weather, rotating modes of action per the label.

    Always follow the product label — it is the law.

    Source: UC IPM; MSU Extension

Pickleworm (Southern Cucurbits)

Pestsevere

Symptoms: entry holes in fruit with sawdust-like frass; tunneled squash and cucumber fruit; chewed buds and flowers; caterpillars boring into stems and fruit

  • CulturalPlant early and use trap/less-preferred cropsstrong evidence — extension confidence

    In southern regions plant early to harvest before populations build, prefer less-susceptible types (e.g., butternut), and remove infested fruit promptly, since larvae feed inside the fruit.

    Source: UF/IFAS; LSU AgCenter

  • OrganicTreat early before larvae bore in· every 5 daysmoderate evidence — extension confidence

    Scout flowers and apply a Bt (B. thuringiensis kurstaki) product targeting young larvae before they enter fruit, since internal feeders are protected once inside; repeat per the label.

    Always follow the product label — it is the law.

    Source: UF/IFAS; UT Extension

  • ChemicalApply insecticide on a tight schedule under heavy pressure· every 1 wkmoderate evidence — extension confidence

    Where pressure is severe, apply a labeled insecticide (e.g., pyrethroid or spinosyn class) timed to flowering and small larvae, per the label, rotating classes.

    Always follow the product label — it is the law.

    Source: UF/IFAS; LSU AgCenter

Root-knot nematodes

Nematodesevere

Symptoms: galls or knots along roots; stunted plants; yellowing and midday wilting that recovers at night; poor vigor despite good care; patchy poor growth in beds

  • CulturalConfirm with a soil test, then rotate (manage, not cure)strong evidence — extension confidence

    Root-knot nematodes can't be eradicated from garden soil, so confirm via a county Extension nematode assay and rotate beds to non-hosts or resistant varieties (look for VFN-type resistance in tomato).

    Source: Clemson HGIC; UF/IFAS

  • CulturalPlant suppressive cover/rotation cropsmoderate evidence — extension confidence

    A solid planting of French marigolds grown 2+ months and turned under, or cover crops such as sorghum-sudangrass or cowpea, can lower populations between susceptible crops.

    Source: UF/IFAS; Clemson HGIC

  • CulturalSanitation and organic mattermoderate evidence — extension confidence

    Avoid moving infested soil on tools or transplants, build soil organic matter to support beneficial organisms, and keep plants well watered to help them tolerate root damage.

    Source: UC IPM; Clemson HGIC

Southern blight

Diseasesevere

Symptoms: sudden wilting in hot weather; yellowing then collapse of whole plant; white fan-like mold mat at the stem base and soil; tan-brown mustard-seed-sized sclerotia near soil line; girdled rotted lower stem

  • CulturalRemove infected plants and surrounding soil (manage, not cure)strong evidence — extension confidence

    Once a plant collapses it can't be cured; dig out the plant plus the top few inches of nearby soil containing sclerotia and dispose of it, avoiding spread on tools.

    Source: Clemson Land-Grant Press; UC IPM

  • CulturalBury residue and rotatemoderate evidence — extension confidence

    Deep-turn soil to bury sclerotia, remove crop debris at season end, and rotate susceptible solanaceous and legume crops with grasses for several seasons.

    Source: Clemson Land-Grant Press

  • CulturalAdjust soil pH and plant earlymoderate evidence — extension confidence

    Maintain soil pH at the level recommended for the crop, since the disease is worse in low-pH soils, and time plantings so harvest begins before peak summer heat favors the fungus.

    Source: Clemson Land-Grant Press

Squash vine borer

Pestsevere

Symptoms: a vine suddenly wilts at the height of summer; sawdust-like frass at a hole near the stem base; hollowed stem

  • CulturalRow-cover early; bury nodes for backup rootsstrong evidence — extension confidence

    Cover plants until flowering to block the egg-laying moth, then hand-pollinate or uncover. Mounding soil over vine nodes lets the plant re-root past a borer.

    Source: UMN Extension

White mold (Sclerotinia stem rot)

Diseasesevere

Symptoms: water-soaked stem or branch lesions; fluffy white cottony mold on stems and pods; sudden wilting of part of a plant; hard black sclerotia inside or on stems; collapse during cool wet bloom periods

  • CulturalRemove infected plants (manage, not cure)strong evidence — extension confidence

    There's no cure for an infected plant; cut out and bag affected plants including the black sclerotia, and don't compost them, since sclerotia survive years in soil.

    Source: UMN Extension; UC IPM

  • CulturalOpen the canopy and rotatestrong evidence — extension confidence

    Space plants widely, control weeds, orient rows to prevailing wind, and avoid overhead watering at bloom to dry the canopy; rotate to non-host crops (corn or other grasses) for several years.

    Source: UMN Extension; UC IPM

  • CulturalWater at the base, not overheadmoderate evidence — extension confidence

    Use drip or soaker irrigation to keep foliage and the soil surface drier, which discourages the sclerotia germination and mycelial growth that drive white mold.

    Source: UC IPM

Angular Leaf Spot (Cucurbits, bacterial)

Diseasemoderate

Symptoms: small angular water-soaked leaf spots bounded by veins; spots dry and tear leaving holes; milky bacterial ooze on leaf undersides in humidity; water-soaked spots on fruit

  • CulturalUse clean seed, rotate, avoid working wet plantsstrong evidence — extension confidence

    Plant certified pathogen-free seed, rotate 2-3 years away from cucurbits, and never cultivate or harvest while foliage is wet, since this bacterial disease spreads in water and on hands and tools. Bacterial diseases are managed, not cured.

    Source: UMN Extension; UF/IFAS

  • CulturalAvoid overhead irrigationstrong evidence — extension confidence

    Use drip irrigation and space plants for rapid drying, since splashing water spreads the bacteria.

    Source: UMN Extension; Univ. of Illinois Extension

  • ChemicalApply copper preventively in warm humid weather· every 1 wkmoderate evidence — extension confidence

    During warm, moist periods that favor disease, apply a fixed-copper bactericide preventively to slow spread, per the label; copper suppresses but does not eliminate the bacterium.

    Always follow the product label — it is the law.

    Source: UF/IFAS; PNW Handbooks

Anthracnose fruit rot

Diseasemoderate

Symptoms: small sunken circular spots on ripening fruit; spots enlarge with darkened concentric centers; soft rot spreading inward; worse on ripe tomatoes and cucurbit fruit in wet weather

Botrytis gray mold

Diseasemoderate

Symptoms: fuzzy gray-brown mold on leaves, stems, flowers, or fruit; soft watery rot on fruit and blossoms; dieback from cut or wounded stems; mold spreading in cool humid still conditions; blighted flowers that fail to set

  • CulturalRemove infected tissue and old blossomsstrong evidence — extension confidence

    Prune out moldy leaves, stems, and fruit and clear fallen blossoms and debris where the fungus gets started, disposing of them rather than composting.

    Source: UMN Extension; Cornell

  • CulturalImprove airflow and reduce leaf wetnessstrong evidence — extension confidence

    Space and stake plants for good air movement, water at the base in the morning, and harvest ripe fruit promptly so botrytis has fewer cool, humid, wet surfaces to colonize.

    Source: UMN Extension; Cornell

Cucumber beetle

Pestmoderate

Symptoms: yellow beetles with stripes or spots; chewed leaves and flowers; wilting that follows (bacterial wilt risk)

  • CulturalRow-cover early; clean up debrisstrong evidence — extension confidence

    These beetles also spread bacterial wilt, so block them with netting on young plants and remove garden debris where they overwinter.

    Source: Cornell Vegetable MD Online

  • OrganicLabeled insecticide for heavy pressure - label use only· every 1 wk · ~2 wksmoderate evidence — extension confidence

    If wilt risk is high, a labeled product applied in the evening protects pollinators. Follow the label.

    Always follow the product label — it is the law.

    Source: Cornell

Damping-off (seedlings)

Diseasemoderate

Symptoms: seedlings flop over and collapse at the soil line; thin water-soaked pinched stem base; fungus gnats or constantly wet mix

  • CulturalDry out, ventilate, sow into clean mixstrong evidence — extension confidence

    Use sterile seed-starting mix, bottom-water and let the surface dry between waterings, add airflow, and don't over-sow. Damping-off can't be cured once a seedling collapses.

    Source: UMN Extension: Damping-off

Read: starting seeds indoors

Downy mildew

Diseasemoderate

Symptoms: angular yellow patches bounded by leaf veins on top; gray-purple fuzz on the underside; spreads in cool humid weather

  • CulturalSpace, prune, and water at the basestrong evidence — extension confidence

    Improve airflow, remove infected leaves, and keep foliage dry. Resistant cucumber varieties help next season.

    Source: Cornell Vegetable MD Online

  • ChemicalLabeled downy-mildew fungicide - label use only· every 1 wk · ~3 wksmoderate evidence — extension confidence

    In wet seasons a labeled fungicide on a 7-day schedule slows spread. Follow the label.

    Always follow the product label — it is the law.

    Source: Cornell Vegetable MD Online

Iron deficiency (interveinal chlorosis)

Deficiencymoderate

Symptoms: yellowing between veins of youngest leaves while veins stay green; new growth pale or nearly white; bleaching and browning of leaf tips in severe cases; symptoms worst on alkaline high-pH soils; older leaves stay greener than new ones

  • CulturalTest and address soil pHstrong evidence — extension confidence

    Iron is present but unavailable in high-pH soils, so test soil pH and, for the affected bed, lower pH toward the crop's preferred range (especially important for acid-loving blueberries) rather than just adding iron.

    Source: UMN Extension; UF/IFAS

  • OrganicUse chelated iron for a quick correction· every 2 wksmoderate evidence — extension confidence

    A foliar spray or soil drench of chelated iron can green up new growth per the label; soil-applied ferrous iron quickly oxidizes and becomes unavailable in high-pH soil, so chelate plus pH management works best.

    Always follow the product label — it is the law.

    Source: UF/IFAS

Read: diagnosing leaf spots & yellowing

Mosaic virus

Virusmoderate

Symptoms: mottled light-and-dark green leaf patterns; puckered distorted or fern-like leaves; stunted growth; mottled bumpy fruit; spread by aphids and handling

Read: diagnosing leaf spots & yellowing

Potassium deficiency

Deficiencymoderate

Symptoms: yellowing and browning along older leaf margins; scorched curled leaf edges; weak stems; poor or uneven fruit ripening; symptoms starting on lower, older leaves

  • CulturalConfirm with a soil test firststrong evidence — extension confidence

    Edge scorch on older leaves has several causes, so get a soil test before adding potassium; over-applying can lock out magnesium and calcium.

    Source: UMN Extension; Missouri Botanical Garden

  • OrganicApply potassium per soil-test guidancemoderate evidence — extension confidence

    If the test confirms low potassium, apply a potassium source (such as sulfate of potash) at the labeled/test-recommended rate and keep watering even, since drought worsens uptake.

    Always follow the product label — it is the law.

    Source: UMN Extension

Read: diagnosing leaf spots & yellowing

Powdery mildew

Diseasemoderate

Symptoms: white powdery coating on upper leaf surfaces; starts as spots then spreads; leaves yellow and dry under the coating

  • CulturalImprove airflow + remove worst leavesstrong evidence — extension confidence

    Cut out the most heavily coated leaves and thin for airflow; avoid wetting foliage late in the day.

    Source: UC IPM

  • OrganicPotassium-bicarbonate or sulfur - label use only· every 1 wk · ~4 wksmoderate evidence — extension confidence

    Apply a labeled potassium-bicarbonate or sulfur fungicide weekly per the label. No sulfur within 2 weeks of oil or in high heat.

    Always follow the product label — it is the law.

    Source: UC IPM

Root rot from overwatering / poor drainage

Diseasemoderate

Symptoms: stunted yellowing plants that wilt despite wet soil; soft brown mushy roots; sloughing root outer layer leaving thread-like core; poor growth in low or compacted wet spots; seedlings collapsing at the soil line

Scab (Cucurbits)

Diseasemoderate

Symptoms: small sunken corky spots on fruit; gummy amber ooze from fruit lesions; angular pale leaf spots that drop out; cavities and dark velvety mold on fruit lesions

  • CulturalPlant resistant cultivars and rotatestrong evidence — extension confidence

    Use scab-resistant cucumber cultivars where available and rotate 2-3 years to non-cucurbit crops, removing crop debris to lower spore carryover.

    Source: UMN Extension; UMass Extension

  • CulturalPromote rapid dryingstrong evidence — extension confidence

    Choose well-drained sites with good air movement, avoid overhead irrigation and dense canopies, and avoid handling plants when wet.

    Source: UMass Extension; Cornell

Slugs & snails

Pestmoderate

Symptoms: large ragged holes with smooth edges; slimy silvery trails; damage worst after rain and overnight

  • CulturalTrap, hand-pick at night, reduce cover· every 2 days · ~3 wksstrong evidence — extension confidence

    Pick at night with a flashlight, set shallow beer traps, water in the morning so soil dries by dusk, and clear damp hiding spots.

    Source: UC IPM: Snails and Slugs

  • OrganicIron-phosphate bait - label use only· every 1 wk · ~3 wksmoderate evidence — extension confidence

    Scatter a labeled iron-phosphate slug bait sparingly per the label; it's pet- and wildlife-safer than metaldehyde.

    Always follow the product label — it is the law.

    Source: UC IPM

Spider mites

Pestmoderate

Symptoms: fine pale stippling/speckling on leaves; fine webbing on undersides in hot dry spells; leaves bronzing and dropping

  • CulturalHose down and raise humidity· every 3 days · ~2 wksstrong evidence — extension confidence

    Mites thrive in hot, dry, dusty conditions. Spray foliage (especially undersides) with water to dislodge them and reduce dust.

    Source: UC IPM

  • OrganicInsecticidal soap or horticultural oil - label use only· every 5 days · ~2 wksmoderate evidence — extension confidence

    Apply to undersides per label; mites resist many products, so soaps/oils are preferred. Not in extreme heat.

    Always follow the product label — it is the law.

    Source: UC IPM

Squash bug

Pestmoderate

Symptoms: bronze/gray shield-shaped bugs at the plant base; bronze egg clusters on leaf undersides; wilting runners

  • CulturalCrush eggs, trap adults, hand-pick· every 3 days · ~4 wksstrong evidence — extension confidence

    Scrape off the coppery egg clusters, lay a board by the base and collect bugs under it each morning. Easiest controlled early.

    Source: UMN Extension: Squash Bug

Stink bugs (brown marmorated and native)

Pestmoderate

Symptoms: cloudy or corky spots on fruit; dimpled or pitted fruit; catfacing on tomatoes; shield-shaped brown or green bugs; barrel-shaped egg clusters on leaf undersides

  • CulturalExclude with row cover and clear nearby weedsstrong evidence — extension confidence

    Cover susceptible crops with floating row cover before bugs arrive, and remove weeds and groundcover near the garden in early spring where stink bugs feed before moving to crops. Lift covers on flowering crops that need pollination.

    Source: UMN Extension; UC IPM Pest Notes

  • CulturalHand-pick bugs and egg masses· every 3 daysstrong evidence — extension confidence

    Scout in the morning and drop adults, nymphs, and egg clusters into a bucket of soapy water; regular hand-picking keeps low populations in check since most garden insecticides work poorly on adults.

    Source: UMN Extension; UC IPM

  • OrganicSpot-treat young nymphs if numbers climb· every 1 wkmoderate evidence — extension confidence

    If small nymphs are abundant, a botanical such as pyrethrin or azadirachtin, or insecticidal oil, may give some suppression per the label; adults are largely unaffected, so rely mainly on exclusion and hand-picking.

    Always follow the product label — it is the law.

    Source: UC IPM

Thrips on fruiting vegetables

Pestmoderate

Symptoms: silvery or stippled flecking on leaves; black specks of frass; distorted or scarred young leaves and fruit; tiny slender insects in flowers; deformed fruit set

  • CulturalRemove weed and crop reservoirsstrong evidence — extension confidence

    Control flowering weeds in and around the garden and remove spent host crops promptly, since thrips build up on these and move onto fruiting vegetables; avoid planting next to onions, garlic, or cereals where thrips numbers spike.

    Source: UC IPM; UF/IFAS

  • CulturalKeep plants vigorous and rinse foliagemoderate evidence — extension confidence

    Water and feed adequately so plants tolerate feeding, and a forceful water spray can knock down populations; reflective mulch can also deter thrips from settling on young plants.

    Source: UC IPM

  • OrganicTreat with spinosad or oil if needed· every 1 wkmoderate evidence — extension confidence

    If thrips are damaging growing points or fruit, spinosad or insecticidal soap/oil can help per the label; rotate modes of action and avoid spraying open blooms to protect pollinators and natural enemies.

    Always follow the product label — it is the law.

    Source: UC IPM; UF/IFAS

Whiteflies

Pestmoderate

Symptoms: clouds of tiny white insects fly up when plants are disturbed; yellowing stippled leaves; sticky honeydew and black sooty mold; weak stunted growth

  • CulturalRemove infested leaves and hose off· every 4 daysmoderate evidence — extension confidence

    Pick off and discard heavily infested lower leaves and rinse colonies off undersides with a strong spray of water; yellow sticky cards help monitor numbers.

    Source: UC IPM: Whiteflies

  • OrganicApply a labeled soap or oil· every 1 wk · ~3 wksmoderate evidence — extension confidence

    Apply a labeled insecticidal soap or neem oil per the label, covering leaf undersides; these reduce but won't eliminate whiteflies, so repeat as needed.

    Always follow the product label — it is the law.

    Source: UC IPM: Whiteflies

Cutworms

Pestmoderate

Unusual this time of year.

Symptoms: seedlings cut off at soil line; transplants toppled overnight; wilted clipped plants in a row; chewed stems near ground; gray-brown caterpillars curled in soil

  • CulturalPlace stem collars on transplantsstrong evidence — extension confidence

    Push a collar (cardboard tube, can, or cup with bottom removed) a couple inches into the soil around each stem so it extends a few inches above ground; this blocks cutworms from reaching the stem.

    Source: UMN Extension: Cutworms; UC IPM: Cutworms

  • CulturalScout soil and hand-remove· every 3 days · ~2 wksstrong evidence — extension confidence

    In the evening or early morning, check the soil around damaged plants and remove curled larvae by hand; tilling beds about two weeks before planting also reduces larvae and pupae.

    Source: UMN Extension: Cutworms; UC IPM: Cutworms

  • OrganicApply a labeled Bt or spinosad· every 1 wk · ~3 wksmoderate evidence — extension confidence

    If damage continues, apply a labeled Bacillus thuringiensis (kurstaki) or spinosad product per the label, targeting small larvae; Bt works best on young first- and second-instar cutworms.

    Always follow the product label — it is the law.

    Source: UC IPM: Cutworms

Phosphorus deficiency

Deficiencymoderate

Unusual this time of year.

Symptoms: stunted plants with dark dull green leaves; reddish or purplish tint on leaves and undersides; delayed maturity and poor fruiting; symptoms worst in cold spring soils; older leaves affected first

  • CulturalCheck soil test and soil temperaturestrong evidence — extension confidence

    Purpling in cold spring soils is often temporary, since cold roots can't take up phosphorus that's actually present; warm weather usually resolves it, so confirm a true shortage with a soil test before adding phosphorus.

    Source: UMN Extension; Missouri Botanical Garden

  • OrganicAdd phosphorus only if the test calls for itmoderate evidence — extension confidence

    If low phosphorus is confirmed, work a phosphorus source into the root zone per the test recommendation, and keep soil pH in range since extreme pH ties up phosphorus.

    Always follow the product label — it is the law.

    Source: UMN Extension

Aphids

Pestlow

Symptoms: clusters of tiny soft-bodied insects on new growth and undersides; sticky honeydew or sooty mold; curled distorted new leaves; ants tending them

  • CulturalBlast off with water· every 3 days · ~2 wksstrong evidence — extension confidence

    Knock colonies off with a strong jet of water in the morning; repeat every few days. Light infestations rarely need more.

    Source: UC IPM: Aphids

  • OrganicInsecticidal soap - label use only· every 1 wk · ~3 wksmoderate evidence — extension confidence

    For persistent colonies apply insecticidal soap to undersides per label. Avoid open flowers.

    Always follow the product label — it is the law.

    Source: UC IPM

Edema (oedema)

Disorderlow

Symptoms: small watery blisters or bumps on leaf undersides; corky tan or brown scabby spots on leaves and stems; yellow flecking on upper leaf surface; worse in cool cloudy humid spells; not spreading plant to plant

Magnesium deficiency

Deficiencylow

Symptoms: yellowing between the veins of older leaves; veins stay green (interveinal); common in sandy soils and containers

  • CulturalConfirm with a soil test, then correct· every 2 wks · ~4 wksmoderate evidence — extension confidence

    Interveinal yellowing on older leaves suggests magnesium. Confirm with a test; if low, a dilute Epsom-salt foliar spray is a short-term fix while you amend the soil.

    Source: UMN Extension

Read: diagnosing leaf spots & yellowing

Nitrogen deficiency

Deficiencylow

Symptoms: oldest leaves uniformly pale yellow; plant pale and slow overall; common in containers and after heavy rain

  • CulturalFeed with balanced fertilizer· every 2 wks · ~4 wksstrong evidence — extension confidence

    Apply a balanced organic fertilizer or fish emulsion; new growth greens up within ~2 weeks. Don't overcorrect.

    Source: UMass Extension

Read: diagnosing leaf spots & yellowing

Poor cucurbit fruit set

Disorderlow

Symptoms: small fruit yellow, shrivel, and drop off; lots of flowers but little fruit; misshapen lopsided fruit; few bees visiting; worse in heat or cool rainy spells

Transplant shock

Disorderlow

Unusual this time of year.

Symptoms: wilting or drooping right after transplanting; stalled growth for days after setting out; leaf scorch or edge browning on new transplants; temporary yellowing; recovery once roots establish

  • CulturalWater in well and provide shade· every 1 days · ~1 wksstrong evidence — extension confidence

    Water transplants in thoroughly at planting and keep the root zone evenly moist for the first week or two, and provide temporary shade during hot, sunny, or windy spells to reduce stress while roots establish.

    Source: UMN Extension; Missouri Botanical Garden

  • CulturalHarden off and plant gently next timestrong evidence — extension confidence

    Most plants recover on their own; to prevent recurrence, harden off seedlings before planting, set them out in mild weather or evening, and avoid disturbing the roots when transplanting.

    Source: UMN Extension