Why Does My Nasturtium Look Sickly?

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

Are the leaves stippled and distorted?

Do the leaves have small, water-soaked spots?

Are the roots enlarged and clublike, plants are stunted with yellowish leaves that wilt during the day?

Do the leaves have large, ragged holes in them?

Are the leaves curled and yellow?

Are there large or small holes in leaves, damage may be extensive?

Have the leaves been tunneled?

Are the leaves mottled with dark green?

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.

Bacterial leaf spot causes circular water-soaked spots on leaves. These spots turn brownish-black and may spread to form large patches of dead tissue. To prevent the spread of this disease, avoid working around wet plants. Remove and destroy affected parts. Spray Bordeaux mix on remaining plants.

Enlarged and clublike roots are most likely caused by fungal disease - Club root. Remove and destroy any infected plants. Applying lime to the soil can reduce fungus sporulation.

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.

Distorted, curled leaves are caused by aphids. These tiny insects 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.

Cabbage looper is a pale green caterpillar with white lines running down either side of their body. Looper populations are usually held in check by natural enemies, but if they do become problematic larvae can be hand-picked from the plants. The application of BTK will effectively kill younger larvae.

Leafminers are known pests on nasturtium plants. These tiny pale green fly larvae feed between the upper and lower surfaces of the leaves. Prune off and destroy all infested leaves. Remove debris in fall because it might contain overwintering leafminers. Introducing parasitic wasps is a very effective method of controlling leafminers.

Mottled or streaked leaves are caused by Nasturtium Mosaic Virus. There is no cure for infected plants. Remove and destroy all flowers that have the symptoms of the mosaic virus. Mosaic virus is spread by aphids, so the best way of preventing the disease is to control these insects.

If your plants are suffering from an abnormal flatting of stems, which may cause them to have a fused appearance they may have a condition called Fasciation. The distortion often develops at the base of the plant. It is usually caused by a bacteria or virus and enters through a wound in the plant. Be very careful when handling plants. Remove and destroy any plants that show signs of the disease.