Sunflower
Sunflower is a flower in the Asteraceae family. It grows best in full sun with dry to medium moisture, and is listed for USDA zones 2-13. Plants reach maturity about 7–127 days after planting and sit about 12 inches apart.
Varieties
33 from High Mowing, Seeds Now & True Leaf Market · sorted by days to maturity▸Sunflower Shoots7–14 days
▸Zohar F143–57 days
Pollenless cut flower; 4-6” flowers; 3-4’ tall; Annual
Pollenless sunflower for cut flowers. Greater holding capacity as a cut flower and no mess from shedding pollen. Single-stemmed plants bear flowers with rays of orange-yellow petals surrounding a fully sterile dark center
Growing notes: We have selected these easy-to-grow flower varieties for their individual beauty, for the beneficial insects they attract, and/or suitability for cut flower production. By offering an assortment of hues, heights, growth habits and appearances, we strive to fill your flower needs, whether you are adding color to your home garden or selling bouquets for market. Our varieties are tried-and-true standards that are sure to perform well in a wide range of growing conditions. Many of these varieties are well suited for succession plantings to ensure a continuous harvest throughout the season. Days to maturity are from seeding. M=1,000.
View on High Mowing ↗▸Teddy Bear50–63 days
Good container variety; 2-3’ tall; Annual
Loads of big, golden yellow, puffy-looking blooms. Great selection for a kids’ garden. Sturdy, dwarf plants have an upright habit. Teddy Bear is nice for cutting and equally nice for a colorful garden border. Suitable for containers. 1.3M seeds/oz.
Growing notes: We have selected these easy-to-grow flower varieties for their individual beauty, for the beneficial insects they attract, and/or suitability for cut flower production. By offering an assortment of hues, heights, growth habits and appearances, we strive to fill your flower needs, whether you are adding color to your home garden or selling bouquets for market. Our varieties are tried-and-true standards that are sure to perform well in a wide range of growing conditions. Many of these varieties are well suited for succession plantings to ensure a continuous harvest throughout the season. Days to maturity are from seeding. M=1,000.
View on High Mowing ↗▸Medium Red51–69 days
Great cut flower; Gorgeous blend of red sunflowers; 5-6’ tall; Annual
Beautiful blend of well-branched, red sunflowers ideal for cut flowers and gardens alike. This lovely mix of red sunflowers offers some unique flair as the genetic mix presents a deep and romantic coloration that is hard to resist. Striking in the field or garden, the strong stalks make these colorful blooms an excellent choice for cut flower production. From our partners at De Bolster Organic Seeds. 1.3M seeds/oz.
Growing notes: We have selected these easy-to-grow flower varieties for their individual beauty, for the beneficial insects they attract, and/or suitability for cut flower production. By offering an assortment of hues, heights, growth habits and appearances, we strive to fill your flower needs, whether you are adding color to your home garden or selling bouquets for market. Our varieties are tried-and-true standards that are sure to perform well in a wide range of growing conditions. Many of these varieties are well suited for succession plantings to ensure a continuous harvest throughout the season. Days to maturity are from seeding. M=1,000.
View on High Mowing ↗▸Golden Ray F155–75 days
Pollenless cut flower; 5-6’ tall; Annual
Prolific producer of exceptionally uniform, bright yellow flowers. Multi-branching plants are covered in medium sized, near perfect flowers, making this an ideal variety for commercial production, cut flowers and bouquets. The visual display of these uniform plants is striking; plants are not too tall and are excellent for the garden due to their tidy growth habit. From our partners at Genesis Seeds
Growing notes: We have selected these easy-to-grow flower varieties for their individual beauty, for the beneficial insects they attract, and/or suitability for cut flower production. By offering an assortment of hues, heights, growth habits and appearances, we strive to fill your flower needs, whether you are adding color to your home garden or selling bouquets for market. Our varieties are tried-and-true standards that are sure to perform well in a wide range of growing conditions. Many of these varieties are well suited for succession plantings to ensure a continuous harvest throughout the season. Days to maturity are from seeding. M=1,000.
View on High Mowing ↗▸Sunspot (Dwarf)55–65 days
Direct sow; Grows well in full sun; Grows well with raised beds; Matures in <90 days
Sunspot is a dwarf annual sunflower that carries a large golden flower on a plant about 18 to 24 inches tall. Its compact size suits containers and the front of beds. Direct-sow after frost in full sun and keep young plants evenly watered while roots establish.
View on Seeds Now ↗▸Mardi Gras Blend Tall59–81 days
Heirloom; Non-GMO; Annual
70 Days to maturity. Helianthus annuus. Mardi Gras Blend Tall Sunflower Seeds: Non-GMO. Open Pollinated. Ornamental. Annual. The color of these flowers varies from pale yellows to dark reds and looks stunning in the garden. They are free flowering multiple branched and flowered plants with strong stems. They are ideal for cut flowers. Each flower grows to be 5 inches when bloomed. Approximately 400 Seeds / Ounce.
View on True Leaf Market ↗▸Fireworks Blend60–80 days
Great cut flower; 8’ tall; Annual
A dreamy blend of vibrant sunflowers ranging in hues from light, lemon yellow to deep, burgundy red. This gorgeous blend of summer sun is reminiscent summer evenings with beautiful colors that light up the landscape. Plants are vigorous and well branched, making the mix an excellent addition to your cut flower assortment. Easy to grow and adaptable, blooms will attract pollinators and bring some magic to your market tables and home gardens. 1.3M seeds/oz.
Growing notes: We have selected these easy-to-grow flower varieties for their individual beauty, for the beneficial insects they attract, and/or suitability for cut flower production. By offering an assortment of hues, heights, growth habits and appearances, we strive to fill your flower needs, whether you are adding color to your home garden or selling bouquets for market. Our varieties are tried-and-true standards that are sure to perform well in a wide range of growing conditions. Many of these varieties are well suited for succession plantings to ensure a continuous harvest throughout the season. Days to maturity are from seeding. M=1,000.
View on High Mowing ↗▸Lemon Queen60–80 days
Excellent cut flower; Attracts bees; 8-10’ tall; Annual
Buttery, pale yellow petals contrast nicely with a wide brown center. This well-known variety has one large main flower followed by smaller, branching secondary flowers of excellent quality. Each flower has a long stem and holds well in bouquets. Plants bloom for a long period of time. 700 seeds/oz.
Growing notes: We have selected these easy-to-grow flower varieties for their individual beauty, for the beneficial insects they attract, and/or suitability for cut flower production. By offering an assortment of hues, heights, growth habits and appearances, we strive to fill your flower needs, whether you are adding color to your home garden or selling bouquets for market. Our varieties are tried-and-true standards that are sure to perform well in a wide range of growing conditions. Many of these varieties are well suited for succession plantings to ensure a continuous harvest throughout the season. Days to maturity are from seeding. M=1,000.
View on High Mowing ↗▸Evening Colors Blend61–83 days
Great cut flower; Attracts bees and butterflies; 8’ tall; Annual
Each plant carries an amazing variety of gold and pale yellow flowers with dusty- rose to pink rings. An unusual genetic mix with few solid colors and chocolatey-brown centers. Well-branched; stems average 18” long with single heads. Great for bouquets and provides a long season of color. 1.1M seeds/oz.
Growing notes: We have selected these easy-to-grow flower varieties for their individual beauty, for the beneficial insects they attract, and/or suitability for cut flower production. By offering an assortment of hues, heights, growth habits and appearances, we strive to fill your flower needs, whether you are adding color to your home garden or selling bouquets for market. Our varieties are tried-and-true standards that are sure to perform well in a wide range of growing conditions. Many of these varieties are well suited for succession plantings to ensure a continuous harvest throughout the season. Days to maturity are from seeding. M=1,000.
View on High Mowing ↗▸Goldie (Organic)64–86 days
Organic; Non-GMO; Annual
75 Days to maturity. Helianthus annuus. Goldie Organic F1 Hybrid Sunflower Seeds: Non-GMO. Organic. Ornamental. Annual. Goldie is feathery and unique hybrid sunflower that looks like pompoms of sunshine! If you are looking for bright yellow double flowers that are large and fuzzy, then Goldie is the sunflower for you. These seeds are the same as Goldie Sunflower Seeds, but are produced using organic best practices. Around 400 Seeds / Ounce.
View on True Leaf Market ↗▸Goldy Double64–86 days
Attracts bees; 5-6’ tall; Annual
Large, fully double and fuzzy blooms soft enough to cuddle with. Multi-branching plants have numerous bright yellow, eye-catching, pompom-like flowers adored by everyone. Will bloom longer than any other type; highly vigorous and productive. 550 seeds/oz.
Growing notes: We have selected these easy-to-grow flower varieties for their individual beauty, for the beneficial insects they attract, and/or suitability for cut flower production. By offering an assortment of hues, heights, growth habits and appearances, we strive to fill your flower needs, whether you are adding color to your home garden or selling bouquets for market. Our varieties are tried-and-true standards that are sure to perform well in a wide range of growing conditions. Many of these varieties are well suited for succession plantings to ensure a continuous harvest throughout the season. Days to maturity are from seeding. M=1,000.
View on High Mowing ↗▸All Sorts Surprise Mix65–100 days
Direct sow; Grows well in full sun; Grows well with raised beds; Matures in <90 days
Includes a mix of all sorts of different sunflowers! Be surprised as you watch they grow in your garden. Follow SeedsNow.com's board Sunflowers on Pinterest.
View on Seeds Now ↗▸Chocolate Cherry65–90 days
Direct sow; Grows well in full sun; Grows well with raised beds; Matures in <90 days
Chocolate Cherry is a branching heirloom sunflower growing 6 to 7 feet tall and producing multiple blooms per plant. The 5 to 8 inch flowers have velvety, deep mahogany-red to burgundy petals surrounding a dark center. A low-pollen, long-lasting variety prized as a cut flower, it blooms from midsummer into early fall.
View on Seeds Now ↗▸Dwarf Sunspot65–80 days
Non-GMO; Annual
65-80 Days to maturity. Helianthus annuus. Dwarf Sunspot Sunflower Seeds: Non-GMO. Open Pollinated. Ornamental. Annual. Heirloom. Dwarf Sunspot sunflower seeds grow the ideal compact alternative to summer's tallest and most magnificent blooms. Dwarf Sunspot sunflower seeds grow a convenient 30-36 inches tall semi-dwarf, but still boast the same lustrous 10 inch wide golden-yellow heads as 100 inches tall varieties! Dwarf Sunspot sunflowers are vigorous garden performers, easy to grow from seed, and tolerant to drought and poor soils. Sunflower Dwarf Sunspot seeds mature as early as 2-3 months and make a quick and fun grow for novice gardeners to try out in a flower bed, walkway, fencing, or indoor planter. ~510 seeds/oz.
View on True Leaf Market ↗▸Skyscraper68–92 days
Heirloom; Non-GMO; Annual
80 Days to maturity. Helianthus annuus. Skyscraper Sunflower Seeds: Non-GMO. Open Pollinated. Ornamental. Annual. This sunflower is so tall you will need a big ladder to reach it, and even then you won't be able to reach the top! The yellow flowers are giant at 14 inches across. Can have single heads or many per stalk. Large edible seed. Heat and drought tolerant. Approx. 275 seeds/ounce.
View on True Leaf Market ↗▸Skyscraper (Organic)68–92 days
Organic; Non-GMO; Annual
80 Days to maturity. Helianthus annuus. Organic Skyscraper Sunflower Seeds: Non-GMO. Open Pollinated. Ornamental. Annual. The skyscraper sunflower is beautiful and grows 12 feet tall with long, strong stalks holding the flowers up into the sky. As it looks upon the sky, the flowers are 14 inches in diameter. The petals are a soft yellow with an orange into green centers. The seeds are large and edible. Approximately 400 Seeds / Ounce.
View on True Leaf Market ↗▸Sungold Dwarf68–92 days
Heirloom; Non-GMO; Container; Annual
Helianthus annuus (80 days) Sunflower Dwarf is also known as "Teddy Bear". Sungold grows 24" to 36" tall and has profusion of bushy yellow sunflowers. Very easy to grow and a great project for kids. ~1,420 seeds/oz.
View on True Leaf Market ↗▸Sun Gold (Tall)70–90 days
Direct sow; Grows well in full sun; Grows well with raised beds; Matures in <90 days
Giant "Teddy Bear" type sunflower - Seven to eight inch bold yellow flowers - Plants grow to 6 feet tall - Easy to grow
View on Seeds Now ↗▸Earthwalker75–85 days
Non-GMO; Annual
75-85 Days to maturity. Helianthus annuus ’Earthwalker’. Earthwalker Sunflower Seeds: Non-GMO, open-pollinated, ornamental, annual, drought-tolerant, heat-tolerant, multi-branching sunflower. Earthwalker sunflower seeds grow deeply colored and complement any outdoor space. These late bloomers are perfect for ushering in fall with autumnal shades that will feel right at home among mums and other fall bloomers. As branching sunflowers, each plant will burst forth with multiple blooms that are perfect for using as cut flowers to excite the eye from summer through fall. Approximately 1,100 Seeds / Ounce.
View on True Leaf Market ↗▸Hella Sonnenblume75–80 days
Superb cut flower; 2-3’ tall; Annual
A stunning dwarf sunflower for bouquets. Lovely 4” diameter gold-petaled blooms are incredibly uniform on sturdy 12” stems. Cute, undeniably dwarf plants reach only 3.5’ in height, but from the main stalk each produces an abundance of long, ruler-straight stems perfect for cutting. Easy to harvest with long vase life—an instant stand-out in our trials. From our friends at Swiss biodynamic seed company Sativa. 2M seeds/oz.
Growing notes: We have selected these easy-to-grow flower varieties for their individual beauty, for the beneficial insects they attract, and/or suitability for cut flower production. By offering an assortment of hues, heights, growth habits and appearances, we strive to fill your flower needs, whether you are adding color to your home garden or selling bouquets for market. Our varieties are tried-and-true standards that are sure to perform well in a wide range of growing conditions. Many of these varieties are well suited for succession plantings to ensure a continuous harvest throughout the season. Days to maturity are from seeding. M=1,000.
View on High Mowing ↗▸Indian Blanket75–90 days
Heirloom; Non-GMO; Annual
75-90 Days to maturity. Helianthus annuus. Indian Blanket Sunflower Seeds: Non-GMO. Open Pollinated. Ornamental. Annual. Indian Blanket blooms gorgeous flowers that are shades of orange, red, and yellow. These beautiful flowers are sure to add color to the garden. Indian Blanket is multi-heading and is the perfect sunflower for any summer garden or kitchen table. Approximately 400 Seeds / Ounce.
View on True Leaf Market ↗▸Hopi Black Dye81–109 days
Natural dye source; 7-11’ tall
A Hopi heirloom prized for its purple-black seeds, used especially for dyeing baskets. High Mowing sold this variety in our very first catalog, and we brought it back in part to complete the circle of our journey and in part because it’s a great variety. Like us, it’s scrappy and resilient and does a lot with a little. The seeds are good for dye but also for food or feed, and are the best for de-hullling. The massive, tall flowers are classically sunflower beautiful, with yellow rays around purple-black centers. Grown for countless generations, this variety will almost certainly still be used to make dye a hundred years from now. 500 seeds/oz.
Growing notes: We have selected these easy-to-grow flower varieties for their individual beauty, for the beneficial insects they attract, and/or suitability for cut flower production. By offering an assortment of hues, heights, growth habits and appearances, we strive to fill your flower needs, whether you are adding color to your home garden or selling bouquets for market. Our varieties are tried-and-true standards that are sure to perform well in a wide range of growing conditions. Many of these varieties are well suited for succession plantings to ensure a continuous harvest throughout the season. Days to maturity are from seeding. M=1,000.
View on High Mowing ↗▸Velvet Queen85–100 days
Great cut flower; Attracts bees; 5’ tall; Annual
Deep velvety, crimson blooms accented with traces of yellow around a black center. Foliage is distinct and attractive, and the plants are free branching, bearing lots of 5-6” blooms that are lovely for cutting. A chic and sophisticated sunflower for cut flower connoisseurs. 550 seeds/oz.
Growing notes: We have selected these easy-to-grow flower varieties for their individual beauty, for the beneficial insects they attract, and/or suitability for cut flower production. By offering an assortment of hues, heights, growth habits and appearances, we strive to fill your flower needs, whether you are adding color to your home garden or selling bouquets for market. Our varieties are tried-and-true standards that are sure to perform well in a wide range of growing conditions. Many of these varieties are well suited for succession plantings to ensure a continuous harvest throughout the season. Days to maturity are from seeding. M=1,000.
View on High Mowing ↗▸All Sorts Mixture90–110 days
Annual
90-110 days. All Sorts Mix sunflower seeds grow one of the most spectacular, vibrant, and unique pairings of color and size in this blend of summertime classics. All Sorts Mix seeds grow hardy, drought tolerant sunflowers ranging from 24-144" tall with brilliant 8-12" heads bursting of unique color including Velvet Queen, Autumn Beauty, Sunspot, Mammoth, Teddy Bear, Lemon Queen, and Sungold. All Sorts Mix seeds are an ideal grow to showcase along the back of a garden, fence, siding, or any wide open spaces. All Sorts Mix sunflower seeds grow fun, exclusive floral shop favorites used as exciting centerpieces for more traditional fresh cut arrangements.
View on True Leaf Market ↗▸Autumn Beauty Blend90–100 days
Food for birds and bees; 7’ tall; Annual
An explosion of 4-6” flowers in the rich colors of fall. Flowers seem to glow in an array of gold, bronze, orange and scarlet tones with lots of bicolors. Well-branched, tall plants with numerous flowers over a long season. Good bird food with lots of oil-rich seeds. 1.1M seeds/oz.
Growing notes: We have selected these easy-to-grow flower varieties for their individual beauty, for the beneficial insects they attract, and/or suitability for cut flower production. By offering an assortment of hues, heights, growth habits and appearances, we strive to fill your flower needs, whether you are adding color to your home garden or selling bouquets for market. Our varieties are tried-and-true standards that are sure to perform well in a wide range of growing conditions. Many of these varieties are well suited for succession plantings to ensure a continuous harvest throughout the season. Days to maturity are from seeding. M=1,000.
View on High Mowing ↗▸Autumn Beauty Mix90–100 days
Annual; Non-GMO
90-100 Days to maturity. Helianthus annuus. Autumn Beauty Mix Sunflower Seeds: Non-GMO. Open Pollinated. Ornamental. Annual. Heirloom. Autumn Beauty Mix seeds grow one of the summer's most explosive and familiar bordering flowers. Autumn Beauty seeds promise your garden brilliant 8-inch heads bursting with a mix of bronze, golden, purple, mahogany, and yellow sunburst. Autumn Beauty sunflower seeds grow up to 60 inches tall, and its countless seeds serve as a natural bird feeder all season long. Autumn Beauty Mix seeds are a simple, easy-to-grow addition to many hot, drought-prone gardens across North America. ~1,700 seeds/oz.
View on True Leaf Market ↗▸Evening Sun90–110 days
Direct sow; Grows well in full sun; Grows well with raised beds; Matures in <90 days
Evening Sun is a branching annual sunflower with flowers in burgundy, rust, gold, and warm bicolors. Plants can reach 6 to 8 feet and may need support in windy sites. Direct-sow in full sun after frost and leave several side branches for a longer cut-flower harvest.
View on Seeds Now ↗▸Mammoth Grey Stripe90–110 days
Non-GMO; Annual
90-110 Days to maturity. Helianthus annuus. Mammoth Grey Stripe Sunflower Seeds: Non-GMO. Open Pollinated. Ornamental. Annual. Mammoth sunflower seeds grow one of the tallest, brightest, and most breathtaking flowers in the world! Mammoth sunflower seeds grow an unbelievable 9-12 feet tall and are famous for their stunning 12 inch blooms. Mammoth sunflowers are one of the most resilient and fastest-growing sunflower varieties in the world. Mammoth sunflower seeds are an ideal crop for bird enthusiasts because the countless seeds per head will keep birds well-fed and returning for more all season long. Approximately 375 Seeds / Ounce.
View on True Leaf Market ↗▸Mammoth Grey Stripe (Organic)90–110 days
Heirloom / Open Pollinated; Annual; Organic
90-110 Days to maturity. Helianthus annuus. Organic Mammoth Grey Stripe Sunflower Seeds: Non-GMO. Open Pollinated. Ornamental. Annual. Mammoth sunflower seeds grow one of the tallest, brightest, and most breathtaking flowers in the world! Mammoth sunflower seeds grow an unbelievable 9-12 feet tall and are famous for their stunning 12-inch blooms. Mammoth sunflowers are one of the most resilient and fastest-growing flowers in all of North America. Approximately 375 Seeds / Ounce.
View on True Leaf Market ↗▸Red Sun90–110 days
Non-GMO; Annual
90-110 Days to maturity. Helianthus annuus. Red Sun Sunflower Seeds: Non-GMO. Open Pollinated. Ornamental. Annual. Heirloom. Red Sun seeds grow one of the summer's rarest and most unique blooms, stunning 60-72 inch tall branching sunflowers with eye-catching 5-6 inch heads of smoky burgundy, bronze, and copper. Red Sun sunflowers are grown for their rich, warm petals and chocolate-seeded centers that promise to keep the birds fed and coming back all season long. Red Sun seeds mature in as early as 90 days and make a quick and fun grow for novice gardeners to try out in the back of a garden. Approximately 500 seeds/ounce.
View on True Leaf Market ↗▸Ring of Fire90–110 days
Non-GMO; AAS Winner; Annual
90-110 Days to maturity. Helianthus annuus. Organic Ring of Fire Sunflower Seeds: Non-GMO. Open Pollinated. Ornamental. Annual. Ring of Fire sunflower seeds are an easy and award-winning grow for invigorating any dull or tired garden. Ring of Fire seeds grow unique 5-6 inch golden yellow sunflower heads, erupting with a fiery sunburst-mahogany ring around a heavily-seeded, chocolate center. Ring of Fire sunflowers debuted as a 2001 AAS award-winning selection for "being different from other flowers and standing out in a crowd of plain gold or yellow flowers." Ring of Fire sunflower seeds grow hardy, vigorous garden performers and are a timeless seasonal favorite to add as a centerpiece to any fresh-cut arrangement, basket, or bouquet.
View on True Leaf Market ↗▸Mammoth94–127 days
Food for birds and bees; Fun for kids; 12’ tall; Annual
The giant of all sunflowers with tall, thick stalks supporting huge heads that tower over the garden. This single-stemmed variety is a very fast and vigorous grower, perfect for creating living walls or fences, sunflower houses, kids’ gardens and more. Also a great variety for edible seeds or feeding the birds. Towering plants are beloved by children, birds and bees. 295 seeds/oz.
Growing notes: We have selected these easy-to-grow flower varieties for their individual beauty, for the beneficial insects they attract, and/or suitability for cut flower production. By offering an assortment of hues, heights, growth habits and appearances, we strive to fill your flower needs, whether you are adding color to your home garden or selling bouquets for market. Our varieties are tried-and-true standards that are sure to perform well in a wide range of growing conditions. Many of these varieties are well suited for succession plantings to ensure a continuous harvest throughout the season. Days to maturity are from seeding. M=1,000.
View on High Mowing ↗
Plant spacing
In a square-foot bed, space sunflower about 12 in apart — that fits 1 plant in each 1-foot square (1×1). Wider rows or containers space the same.
Plan your sunflower planting
Add sunflower 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
Growing timeline
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 (2)
- CornEvidence tier C: Traditional practice with plausible mechanism but limited empirical replicationstructural-support, pollinator-attract
Sunflowers planted in or near corn rows provide structural niches for pole beans and feed pollinators and seed-eating birds; not a documented yield benefit but a common Midwest home-garden practice.
Source: S8
- Squash (Cucurbita spp., generic)Evidence tier C: Traditional practice with plausible mechanism but limited empirical replicationpollinator-attract, structural-support
Sunflowers attract native bees that pollinate squash; vines occasionally use lower sunflower stems as support. Manage spacing to prevent shading.
Source: S8
Avoid planting near (2)
- Common ArtichokeEvidence tier B: Extension consensus across multiple US/Canada land-grant institutionsdisease-host
Globe artichoke is susceptible to Sclerotinia and Verticillium that also infect sunflower; UC IPM advises against following sunflower in artichoke ground.
Region: California production.
Source: UC IPM
- Common BeanEvidence tier B: Extension consensus across multiple US/Canada land-grant institutionsallelopathy-negative
Helianthus annuus produces allelopathic terpenes (chlorogenic and isochlorogenic acids, sesquiterpene lactones) released by roots and decomposing residues that inhibit germination and growth of bean, potato, and several small-seeded vegetables. Documented in peer-reviewed allelopathy literature and Northern Plains extension trials.
Timing: Avoid direct seeding small-seeded crops within 1 m of sunflower row, and into ground freshly cleared of sunflower residue.
Source: S22, Putnam, 1988
Sources cited
- S22
- University of Saskatchewan / Saskatchewan Ministry of Agriculture
- S3
- UC IPM (University of California Agriculture and Natural Resources)
- S33
- Putnam, 1988 — cereal rye allelopathy review
- S8
- Iowa State University Extension and Outreach
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.
- 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.
Mulch to suppress weeds and retain moisture
Mulch- Routine careApply organic mulch around plantsstrong evidence — extension confidence
Spread a few inches of straw, shredded leaves, or compost around established plants (keeping it off stems) to hold soil moisture, suppress weeds, and moderate soil temperature; wait until soil has warmed for heat-loving crops.
Protect the garden from rabbits and voles
Protection- Routine careFence out rabbitsstrong evidence — extension confidence
Surround beds with 1-inch mesh chicken wire at least 2 feet tall with the bottom buried or staked down a few inches so rabbits can't push under it.
- Routine careReduce vole habitat and guard stemsstrong evidence — extension confidence
Keep grass and mulch pulled back from plant bases and crowns to remove vole cover, mow surrounding vegetation, and use hardware-cloth guards around vulnerable woody stems before winter.
Clean up debris and sanitize at season end
SanitationUnusual 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.
- 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.
Harden off seedlings
ProtectionUnusual this time of year.
- Routine careGradually expose plants to the outdoors· every 1 days · ~2 wksstrong evidence — extension confidence
Starting about two weeks before transplanting, set seedlings outside in a sheltered, shady spot for a few hours and lengthen their time and sun exposure each day, avoiding windy days, to prevent transplant shock.
- Routine careEase back on water and transplant on a mild daystrong evidence — extension confidence
Water a little less during hardening (without letting plants wilt) to toughen growth, then transplant in late afternoon or on a cool, cloudy, calm day.
Succession-sow quick crops
CareUnusual this time of year.
- Routine careSow small batches on a schedule· every 2 wksstrong evidence — extension confidence
Plant short rows of fast crops like radishes, bush beans, and lettuce every two to three weeks rather than all at once, so you get a steady harvest and one bad weather spell won't ruin the whole planting.
Something looks wrong?
Describe what you see on your sunflowerand we'll rank the likely causes — most likely first, least-invasive fix first.
Tomato spotted wilt virus
Virussevere- CulturalRemove infected plants (cannot be cured)strong evidence — extension confidence
There is no cure once a plant is infected, so promptly pull and dispose of symptomatic plants to reduce the virus reservoir that thrips spread to healthy plants.
- CulturalStart clean and control weeds and thripsstrong evidence — extension confidence
Use virus- and thrips-free transplants, choose resistant varieties (Sw-5 tomatoes, Tsw peppers) where available, and control weeds around the garden that harbor both virus and thrips vectors.
White mold (Sclerotinia stem rot)
Diseasesevere- 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.
- 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.
- 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.
Botrytis gray mold
Diseasemoderate- 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.
- 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.
Japanese beetles
Pestmoderate- CulturalHandpick into soapy water· every 1 days · ~4 wksstrong evidence — extension confidence
In early morning when beetles are sluggish, knock them into a bucket of soapy water; daily removal also reduces the scent that draws in more beetles. Skip the lure traps, which tend to attract more beetles than they catch.
- CulturalCover plants past bloommoderate evidence — extension confidence
On crops that have finished flowering and set fruit, drape a row cover or netting to keep beetles off without blocking pollination during bloom.
Leafhoppers & aster yellows
Diseasemoderate- CulturalRemove infected plants and weed reservoirsstrong evidence — extension confidence
Aster yellows can't be cured, so pull and discard plants showing yellowing and witches-broom, and clear nearby weedy hosts that harbor the phytoplasma and its leafhoppers.
- CulturalExclude leafhoppers with row covermoderate evidence — extension confidence
On young susceptible crops, a floating row cover keeps egg-laying leafhoppers off and lowers the chance of aster-yellows spread.
Powdery mildew
Diseasemoderate- 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.
- 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.
Root rot from overwatering / poor drainage
Diseasemoderate- CulturalLet soil drain and water lessstrong evidence — extension confidence
Water root rots like Pythium thrive in saturated soil, so cut back watering, let the surface dry between irrigations, and water at the base rather than keeping soil constantly wet.
- CulturalImprove drainage and aerationstrong evidence — extension confidence
Use raised beds, loosen compacted soil, and add organic matter to improve drainage; remove plants that are already rotted since affected roots won't recover.
Slugs & snails
Pestmoderate- 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.
- 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.
Tarnished plant bug / lygus
Pestmoderate- CulturalManage surrounding weedsstrong evidence — extension confidence
Keep broadleaf weeds mowed or removed around the garden, since lygus build up on flowering weeds and move to crops as those weeds dry down; avoid mowing large weedy areas right beside fruiting crops at bloom.
- CulturalVacuum or shake plants to monitor and reduce· every 5 daysmoderate evidence — extension confidence
Tap plants over a light-colored tray to check for nymphs; a handheld vacuum used once or twice weekly can hold low to moderate numbers down on small plantings.
- OrganicTreat nymphs if damage is building· every 1 wkmoderate evidence — extension confidence
For active nymph infestations, azadirachtin or a Beauveria bassiana product can give some control per the label; preserve the parasitic wasps and other natural enemies that help suppress lygus.
Whiteflies
Pestmoderate- 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.
- 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.
Cutworms
PestmoderateUnusual this time of year.
- 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.
- 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.
- 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.
Aphids
Pestlow- 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.
- 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.
Bolting (premature flowering)
Disorderlow- CulturalShade and harvest before boltingstrong evidence — extension confidence
Once a plant bolts it can't be reversed, so harvest at the first sign of stalk formation; 30-50% shade cloth and steady watering during heat help delay bolting in cool-season crops.
- CulturalUse bolt-resistant varieties and succession sowmoderate evidence — extension confidence
Choose heat-tolerant, slow-bolt varieties and stagger small sowings so a heat spell doesn't take out the whole planting.
Earwigs
Pestlow- CulturalTrap and remove· every 1 days · ~2 wksstrong evidence — extension confidence
Set rolled damp newspaper, low tuna-style cans of oil, or short tubes near plants at dusk, then dump trapped earwigs into soapy water each morning; reduce mulch and damp hiding spots near vulnerable seedlings.
- OrganicApply a bait only if damage persists· every 1 wkmoderate evidence — extension confidence
Established plants usually tolerate earwigs, which also eat aphids; if seedlings are being destroyed, a spinosad-based bait labeled for earwigs can help per the label.
Transplant shock
DisorderlowUnusual this time of year.
- 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.
- 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.