Why Does My Strawflower Looks Sickly?

Are the flowers covered with gray mold, leaves may be blotched or discolored?

Are the older leaves turning yellow and wilting, an overall decline in plant vigor is apparent?

Do the leaves have pale areas on upper surfaces and "downy" patches underneath?

Are the leaves greenish-yellow and the growth rate is poor?

Are the leaves stippled and distorted?

Are the stems, crowns, and/or roots rotted, leaves are wilting?

Gray mold on flowers is probably caused by fungal disease - Botrytis blight. You can prevent Botrytis blight disease by planting flowers in areas with good air circulation. Water plants sparsely. Severely infected plants should be removed. Spray weekly with a copper fungicide until the disease is under control.

These symptoms indicate fungal disease Verticillium wilt. Verticillium infects a wide range of plant species. Destroy all infected plants, as there is no cure. Prevent problems by presoaking seed in a 10 percent bleach solution.

Pale areas on upper surfaces of the leaves and "downy" patches underneath are caused by Downy mildew. This fungus spreads quickly during cool, wet nights and warm, humid days. Leaves will wilt and die. Remove and destroy all affected plant parts and encourage good air circulation around plants by thining them. Water plants early in the morning to make sure they dry before nightfall.

Greenish yellow, strap-shaped leaves followed by a poor growth is caused by Aster yellows disease. There is no cure for Aster yellows, so the infected plants should be destroyed. Prevent the disease by controlling leafhoppers. Spray the plants with the insecticidal soap 3 times, once every 3 days.

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.

Strawflowers are susceptible to several Crown or Root rot diseases. Crown injury and excess moisture increase the chances of infection. Choose well-drained sites. Add organic matter to improve soil drainage. Remove and discard infected plants and the surrounding soil.

If your strawflower has large, ragged holes in the leaves the culprits are slugs and snails. Slugs and snails feed on the plant leaves usually at night. To control slugs and snails use diatomaceous earth around your plants. You can also handpick them during the night or use shallow dishes filled with beer as a trap.