Why Does My Verbena Look Unhealthy?

Are the leaves covered with white powder?

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

Are the leaves yellowing, wilting and, dying?

Are there any small, angular, gray-brown spots with defined red-brown margins on leaves?

Are the leaves discolored, fine webbing may be present?

Are the leaves curled and distorted?

Are there any irregular serpentine tunnels in the leaves?

Are the leaves dwarfed, thickened, and wrinkled?

White, powdery patches on the leaves are caused by a fungal disease Powdery mildew. Powdery mildew usually appears in damp places. Encourage good air circulation around the affected plants by thining them and any surrounding plants. Water plants from bellow to keep foliage dry. Any affected leaves should be cut off and removed. The appropriate fungicidal spray will protect your plant from further infections.

Gray mold on flowers is probably caused by fungal disease - Botrytis blight. You can prevent Botrytis blight disease by planting 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.

Yellow leaves that wilt and die usually indicate fungal or bacterial Root rot disease. Poorly drained, overly wet soil promotes rot so choose well-drained sites and add organic matter to improve drainage. Remove and destroy infected plants. Solarize the soil before replanting.

These symptoms indicate fungal disease - Septoria leaf spot. Remove and destroy infected plant debris. Don't handle or brush against plants when they are wet. Rotate plantings. Remove weeds growing nearby.

Spider mites often cause problems for verbena. Hose off plants when symptoms first appear. A strong stream knocks mites off plants and may give control. Introduce predatory mites. For severe infestations, spray plants with insecticidal soap or pyrethrin.

Distorted and 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.

Tunnels in leaves are caused by leafminers. These tiny fly larvae feed within the leaves in meandering mines that become wider as the larvae grow. 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.

Cyclamen mites are translucent, and almost microscopic insects that infest the new leaf and blossom buds. Infested plants do not bloom, or blossoms may be misshapen. Cyclamen mite is not easily controlled when mature plants are badly infested: effective miticides are not available to homeowners, so a commercial applicator may be required for effective miticide applications.

Gall midges are insects whose orange larvae tunnel into young shoots. One-inch-long swellings form around the developing larvae on leaves and stems. Leaves may wilt or turn brown. Prune off and destroy all infested tissue as soon as they appear. If there are a lot of galls on the plant, remove and destroy the infected plant.