Amaranth

Symptoms: swarms of elongated soft-bodied beetles; rapid defoliation of leaves and flowers; gray, black, or striped beetles clustered on plants; skeletonized foliage on tomatoes and beans

• CulturalHand-pick wearing gloves· every 2 days●●Moderatemoderate evidence — extension confidence

  Wear gloves (these beetles release a blistering fluid) and knock beetles into soapy water, or use row cover ahead of swarms; their larvae eat grasshopper eggs, so tolerate light feeding when you can.

  Source: UMN Extension; Missouri Botanical Garden

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• OrganicSpot-treat heavy swarms· every 1 wk●●Moderatemoderate evidence — extension confidence

  If a large swarm threatens a planting, a pyrethrin or other labeled insecticide can knock them back per the label; avoid spraying open blooms to protect pollinators.

  Always follow the product label — it is the law.

  Source: Missouri Botanical Garden

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Symptoms: small round spots with tan-to-gray centers and reddish-purple borders; spots coalescing and turning gray; heavy spotting on outer leaves; foliage browning and dying back in warm humid weather

• CulturalRotate, space out, and water at the base●●●Strongstrong evidence — extension confidence

  The fungus survives on debris and spreads by splashing water, so rotate beds, space plants for airflow, and water at the soil rather than overhead. Remove and discard heavily spotted outer leaves and clear crop residue after harvest.

  Source: UMass Extension; UMN Extension

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• OrganicApply a copper fungicide if spreading· every 10 days●●Moderatemoderate evidence — extension confidence

  If spotting is severe and weather stays warm and humid, apply a labeled copper fungicide preventively per the label, before the disease takes over the planting.

  Always follow the product label — it is the law.

  Source: UMass Extension

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Symptoms: leaves skeletonized between veins; lacy chewed foliage; metallic green-bronze beetles clustered on plants; feeding worst in warm midsummer sun

• CulturalHandpick into soapy water· every 1 days · ~4 wks●●●Strongstrong 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.

  Source: UMN Extension: Japanese beetles; PennState Extension: Japanese Beetles in the Home Garden

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• CulturalCover plants past bloom●●Moderatemoderate 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.

  Source: UMN Extension: Japanese beetles

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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 first●●●Strongstrong 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

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• OrganicApply potassium per soil-test guidance●●Moderatemoderate 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

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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 wks●●●Strongstrong 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

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• OrganicIron-phosphate bait - label use only· every 1 wk · ~3 wks●●Moderatemoderate 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

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Unusual this time of year.

Symptoms: patchy poor germination; seedlings die in stretches; tunneled holes in potatoes and root crops; hard shiny orange-brown worms in soil; thinning stands after sod or grass

• CulturalRotate away from grassy ground●●●Strongstrong evidence — extension confidence

  Avoid planting susceptible crops right after sod, pasture, or grass cover, where wireworms build up; rotate to a less-favored crop and let infested beds dry out between plantings.

  Source: UMass Extension: Wireworms; UC IPM: Wireworms

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• CulturalBait-trap to monitor· every 5 days · ~3 wks●●Moderatemoderate evidence — extension confidence

  Bury pieces of carrot or potato or a handful of soaked wheat seed as bait when soil reaches about 50F, check after several days, and remove the worms you find to gauge and reduce pressure.

  Source: UMass Extension: Wireworms

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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 wks●●●Strongstrong 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

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• OrganicInsecticidal soap - label use only· every 1 wk · ~3 wks●●Moderatemoderate 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

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Symptoms: plant sends up a tall central flower stalk; leaves turn bitter; growth turns leggy; happens during heat and long days in lettuce, spinach, and brassicas

• CulturalShade and harvest before bolting●●●Strongstrong 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.

  Source: UMN Extension: Cool-season crops; PennState Extension: Heat-Proofing Your Vegetable Garden

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• CulturalUse bolt-resistant varieties and succession sow●●Moderatemoderate evidence — extension confidence

  Choose heat-tolerant, slow-bolt varieties and stagger small sowings so a heat spell doesn't take out the whole planting.

  Source: UMN Extension: Cool-season crops

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Symptoms: winding pale tunnels inside the leaf; pale blotches between the upper and lower leaf surfaces; tunnels/blotches that can't be rubbed off because the larva is inside

• CulturalPick mined leaves + row cover· every 5 days · ~3 wks●●Moderatemoderate evidence — extension confidence

  Remove and bag leaves with tunnels, and cover plants with insect netting to block the egg-laying flies. Damage is mostly cosmetic on leafy crops.

  Source: UMN Extension

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