What Is Wrong With My Nicotiana?

Are the leaves stems and buds distorted?

Are the leaves yellow and the plant looks weakened?

Are the nicotiana seedlings clipped off at the soil line?

Are the nicotiana flowers covered with gray mold?

Do the leaves have circular brown spots on them?

Do the leaves have small holes in them?

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.

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.

If the seedlings of your flowers are cut off at the soil level, most likely cause are cutworms. These caterpillars can be 1-2 inches long, brown, or gray. They feed at night by cutting off young plants and sometimes eating them whole. During the day, they are hidden below the soil surface. Control them by introducing parasitic nematodes to the ground. Using BTK spray on the ground will also control their numbers.

Gray mold on nicotiana flowers is probably caused by 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 flowers in areas with good air circulation. Water plants sparsely. Infected plants should be removed. Spray weekly with a copper fungicide until the disease is under control.

Bacterial leaf spot causes circular brown spots on nicotiana 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.

Small holes in nicotiana leaves are caused by Flea beetles. These tiny, black, brown, or bronze beetles hop when disturbed. Larvae are small and white, feed mostly on the undersides of leaves. Prevent problems by covering young plants with row cover. Control severe infestations by spraying or dusting plants with pyrethrin.

Some environmental issues may have caused your nicotiana unhealthy look. Nicotiana grows best in average soil in full sun or partial shade. Water well during hot, dry weather. Give less fertilizer and water in late summer to keep plants blooming longer. Do not grow nicotiana in dusty areas, because sticky, fuzzy leaves attract and hold dirt.