Why Does My Purple Coneflower Look Unhealthy?

Do the leaves and/or flowers have holes in them?

Are the leaves stems and buds distorted?

Are the leaves yellowing and shredding, black sooty mold might have developed?

Are the flowers distorted and the growth is stunted?

Are the leaves stippled and distorted?

Are the flowers discolored and deformed?

Do the leaves have spots?

Are the leaves mottled?

Holes in leaves and flowers are caused by Japanese beetles. Adults of these insects devour leaves, stalks, and flowers of nearly 300 plant species. Their larvae feed on the roots of the plants. Handpick adult beetles into a can of soapy water but make sure to wear gloves as Japanese beetles are blister beetles. Apply parasitic nematodes to the soil to limit beetle grub populations. Use pyrethrin powder or neem oil as a last resort.

Distorted stems, buds, and leaves are caused by aphids. These tiny insects can vary in color, green, pink, black, gray to completely white. They cluster under leaves and on growing tips where they feed on plant sap. Leaves, stems, and buds get distorted and later leaves and flowers drop from the plant. You can control them by washing them off the plant with water spray. Insecticidal soap should be used with severe infestations.

These symptoms indicate Sweet potato whiteflies. These tiny, mothlike flies and their larvae feed by sucking plant juices. Whiteflies secrete honeydew, a sugary substance that makes leaves sticky to the touch. Sweet potato whiteflies can also transfer diseases, such as vector virus. Control whiteflies by eliminating garden weeds and by introducing green lacewings in the garden. Spray infested plants with insecticidal soap every 3 days for 2 weeks.

Eriophyid mites live and feed on the insides of flower buds. Introduce predatory mites. Prune off all affected flowers. For severe infestations, spray plants with insecticidal soap or pyrethrin.

Aster leafhoppers are greenish-yellow, tiny insects that feed on leaf undersides, giving the foliage a finely mottled look. Leaves yellow, shrivel and drop. Besides injury from feeding, leafhoppers transmit the disease aster yellows. Use water or insecticidal soap sprays to dislodge nymphs. Encourage enemies such as big-eyed bugs and parasitic wasps. For control of severe infestations, spray plants with neem or pyrethrin.

Discolored and deformed flowers are caused by Aster yellows disease. This disease is transferred by leafhoppers. There is no cure for Aster yellows, so the affected plants should be destroyed. Prevent the disease by controlling leafhoppers. Spray the plants with the insecticidal soap 3 times, once every 3 days.

Several fungi and bacteria cause leaf spots in purple coneflowers. Remove and discard infected leaves. Thin plants and avoid crowding future plantings. Wash your tools and hands after handling infected plants. Avoid overhead watering. Inspect bedding plants on purchase. Clean up plant debris to remove overwintering sites.

Mottled leaves are caused by viruses - Impatiens necrotic spot virus or Cucumber mosaic virus. There is no cure for this condition. To protect other plants, you should remove and destroy the infected purple coneflowers. Aphids carry the viruses so use insecticidal soap or neem oil to eradicate them.

Some environmental issues or poor growing conditions could have caused purple coneflower sickly look. They like full sun, but endure poor soils and tolerate some drought once established. Shaded sites cause tall, spindly growth, as docs excess fertilization. Pinch in spring to encourage sturdy, branching growth.