Why Do My Geraniums Look Unhealthy?

Are the leaves yellow and the plant looks weakened?

Are the leaves stippled with yellow and the foliage is webbed?

Are the leaves, stems and buds distorted?

Do the leaves have large, ragged holes in them?

Do the stems have rotted sections and the leaves wilt?

Do the leaves have spots?

Do leaves have water-soaked spots on them?

Are the flowers covered with gray mold?

Do the leaves have reddish-brown pustules on their undersides?

Yellow leaves and stunted look are caused by 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. 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.

Spider mites often cause problems for geraniums. You can control spider mites by spraying plants thoroughly with water 2-3 times a day for several days. For severe infestations, spray plants with insecticidal soap or pyrethrin.

Distorted stems and leaves are caused by aphids. These tiny insects can vary in color, green, pink, black, gray and 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.

Large, ragged holes in the leaves are caused by 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.

Stem rot is a fungal disease that starts at the base of plants and works its way upward. It commonly affects cuttings, but can also injure full-grown plants. Stems often turn black. Only take cuttings from healthy plants and stick them in a sterile medium. Remove and destroy affected parts or plants.

A large number of fungi and bacteria cause spots on plant leaves, in a variety of colors, shapes and sizes. 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.

Water-soaked spots on geranium leaves are caused by bacterial blight. The copper spray will help in reducing the spread of the disease. If there are no new pods on the plant, you should remove the diseased plants.

The likely cause for these symptoms is the fungal disease - Botrytis blight. Other symptoms include brown to black spots that may appear on leaves and petals. You can only prevent Botrytis blight disease by planting sweet alyssums in areas with good air circulation. Water sweet alyssums sparsely. Infected plants should be removed. Spray weekly with a copper fungicide until the disease is under control.

Pelargonium rust is a fungal disease that causes reddish-brown pustules to develop on the undersides of leaves. Yellow areas form directly over pustules on the leaf's surface. Remove all infected leaves and apply commercial fungicide. Spray leaves with sulfur early in the season to prevent rust or to treat mild infections.

If there are small holes in unopened buds, the culprits are Geranium or tobacco budworms. This caterpillar tunnels into unopened buds and eats them from the inside out. To prevent the spread of the worms into healthy buds remove any buds showing tiny holes and nearby brown specks. Handpick any visible worms and destroy them.