Oriental poppies are hardy and beautiful, but gardeners often face unexpected challenges. Oriental poppy problems range from poor soil drainage that causes plants to rot, to natural summer dormancy that can look like sudden dieback. Leaves may turn yellow or brown from aphids, or develop black spots from fungal disease. Knowing which signs are harmless and which need treatment helps you keep your poppies thriving year after year.
Dead Or Rotted Plants - Poor Soil Drainage
Poppies will die if their soil is waterlogged over the winter. To improve drainage, build the growing bed higher than the surrounding soil and add lots of organic matter (peat moss, leaf mold or sand).
Plants Die Back In Summer - Normal Dormancy
After oriental poppies bloom in the early summer, their foliage dies back and virtually disappears by the end of July. During the hot weeks of summer the plants are dormant. As fall approaches they begin to produce new young foliage that persists over the winter and produces the new blooms.
Leaves Curled And Distorted - Aphids
Aphids are soft-bodied, pear-shaped sucking insects, about the size of the head of a pin, and may be green, brown or pink. They sometimes cluster in large groups on poppy leaves and stems, especially new, tender ones. Plant growth slows and leaves may turn yellow or brown. Foliage wilts under bright sunlight, or sometimes curls and puckers. Oriental poppies aren't usually severely infested, but if aphid populations look heavy, spray the pests with insecticidal soap every 3 to 5 days. If that doesn't work, spray them with pyrethrum every 5 to 7 days for 2 weeks.
For more information see file on Dealing with Aphids.
Leaves Discolored and Distorted - Leafhoppers
Leafhoppers are wedge-shaped, often brightly-colored insects 1/4 to 1/3 inches long. They hold their wings above their bodies like a roof. They dart sideways or hop suddenly when disturbed. Nymphs and adults suck juices from poppy leaves, buds, and stems, weakening the plants. Affected leaves are finely mottled with white or yellow spots; they eventually shrivel and drop off. Sticky honeydew from the insects' feeding may give foliage a glazed appearance and foster growth of sooty mold. If you've had problems in the past, apply a preventive spray of insecticidal soap and seaweed extract to vulnerable plants during the first month of growth. Later, spray pests with insecticidal soap laced with isopropyl alcohol to control any serious infestations.
For more information see the file Controlling Leafhoppers
Plant Stunted, Leaves Yellowed; Lesions On Roots - Nematodes
Nematodes are not insects, but slender, unsegmented roundworms less than 1/20 inch long. They dwell in the soil, sucking on plant roots. Infested poppy plants will look sickly, wilted and stunted, and often have yellowed or bronzed foliage. Their root systems are poorly developed and sometimes even partially decayed. Plants eventually die. Add lots of organic matter (leaf mold or compost if you have it) to the soil to encourage beneficial fungi. Soak the soil near affected plants with fish emulsion diluted in water which may repel the nematodes.
For more information see file on Dealing with Nematodes.
Deformed or Dwarfed Flowers - Tarnished Plant Bug
The 1/4 inch tarnished plant bug is mottled with markings of yellow, brown and black. Look for a black-tipped yellow triangle on each of its sides. The active insect sucks young poppy shoots and especially buds, causing deformed or dwarfed flowers. Tarnished plant bugs appear in early spring, becoming more numerous toward the end of summer. In the morning, when the bugs are least active, spray them with pyrethrum laced with isopropyl alcohol once every 3 days. If the infestation is heavy, dust plant surfaces with sabadilla. Thorough fall and spring cleanup of plant debris may prevent infestations entirely.
For more information see the file on Controlling Plant Bugs
Water-soaked Spots On Leaves - Bacterial Blight
Bacterial blight can cover all above ground parts of the poppy plant with black or water-soaked areas ringed by translucent markings. Remove and destroy affected plants. A sulfur spray or other fungicide may provide some control.
For more information see the file on Controlling Fungal Disease
Foliage Burned - Dog
Dog urine may discolor and kill poppy foliage. Spraying foliage with an anti-transpirant gives some protection. For persistent problems, screen the plants or spray them with an aerosol pet repellent. Dealing With Dogs
In Case Your Poppies Confuse You
What is eating my poppy leaves?
The most common pests eating poppy leaves are flea beetles, poppy root weevils, aphids, slugs, snails, cutworms, and caterpillars. Larger animals like squirrels or deer may also nibble young plants.
Common culprits and signs
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Flea beetles – tiny beetles that leave small “shotgun” holes in young leaves.
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Poppy root weevils – adults chew leaves of small plants; larvae damage roots underground.
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Aphids – clusters of tiny insects that curl and yellow leaves.
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Slugs and snails – ragged holes with shiny slime trails left behind.
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Cutworms – caterpillars that cut young stems at soil level.
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Other caterpillars – chew irregular holes in leaves.
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Squirrels or deer – may eat buds, flowers, or entire plants.
How to identify and fix it
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Inspect leaves for holes, curling, or trails.
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Check the soil and stems for hidden pests.
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Hand-pick larger insects, slugs, or snails.
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Use insecticidal soap for aphids; organic bait for slugs and snails.
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Protect plants from deer or squirrels with netting or repellents.
Why are my poppy leaves turning brown?
Poppy leaves can turn brown for several reasons, ranging from natural dormancy to pests and disease. The most common causes are watering issues, fungal blight, heat stress, and normal summer dieback in Oriental poppies.
Possible causes to check:
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Poor soil drainage / overwatering – waterlogged roots rot, leading to brown or dead leaves.
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Underwatering – too little moisture causes wilting and crisp brown foliage.
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Normal dormancy – Oriental poppies naturally brown and die back after blooming in early summer, then regrow in fall.
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Aphids or leafhoppers – sap-sucking insects that cause curling, yellowing, and eventual browning.
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Fungal or bacterial blight – diseases that create brown spots, wilting, or leaf drop.
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Environmental stress – extreme heat, too much sun, or fertilizer burn can scorch leaves.
What to do:
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Check soil moisture and drainage; adjust watering.
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Inspect plants for aphids, mites, or leafhoppers.
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Remove diseased leaves and use fungicide if needed.
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Don’t panic if Oriental poppies brown in midsummer — it may just be their natural dormancy cycle.
Why are my oriental poppies leaves turning yellow?
Yellow leaves on oriental poppies are usually nothing to panic about. As covered above, the most common reasons are summer dormancy (plants naturally die back after blooming), pests like aphids or leafhoppers, or nematodes in the soil. In each case, the foliage may yellow before turning brown or dropping.
Outside of these issues, yellowing can also happen from watering problems, either too much or too little moisture, or from nutrient stress if the soil is depleted. Check if the timing lines up with normal dormancy, inspect the leaves closely for pests, and feel the soil for signs of poor drainage or dryness.
Why is my poppy plant dying?
Poppy plants usually die from poor soil drainage, root pests, or disease, though sometimes what looks like dying is just the plant’s natural dormancy. Oriental poppies, in particular, fade back after blooming in early summer and reappear in fall.
Other causes include waterlogged soil that rots roots, nematodes that weaken and yellow foliage, or bacterial blight that creates black or water-soaked spots. Even dog urine can scorch foliage. If your poppy is wilting outside its normal dormancy period, check the soil drainage, look for pests on the leaves and roots, and remove any infected parts.
When do oriental poppies bloom?
Oriental poppies bloom in late spring to early summer, typically May to June. Their showy flowers last for a short period—often just one to two weeks—before the foliage dies back in midsummer.
This dieback is not a sign of disease but part of the plant’s natural dormancy cycle. As fall arrives, oriental poppies send up fresh foliage that persists through winter and fuels the next season’s blooms. Deadheading spent flowers may help keep the plants tidy but won’t significantly extend bloom time.
