Why Does My Viburnum Shrub Look Unhealthy?

Are the leaves curled and yellow?

Have the leaves and flowers been skeletonized?

Are there holes in twigs, sawdust may be present?

Does the whole plant look stunted, leaves have been discolored?

Are the leaves and branches covered with small bumps?

Do the leaves have silvery pallor?

Do the leaves have sunken spots?

Do the stems have swollen, tumor-like growths on them?

Are the leaves blotched?

Are the leaves covered with white powder?

Are the leaves pale on their upper side and are there any dusty blisters on the undersides?

Have the bark and the roots been gnawed?

Distorted, curled leaves are caused by aphids. These insects cluster under leaves and on growing tips where they feed on plant sap. You can control them by washing them off the plant with water spray. Insecticidal soap should be used with severe infestations.

Asiatic garden beetles skeletonize new leaves, flowers, roots, and the bases of young stems. They are most active at night. The larvae are grayish, 3/4 inch long, and bent in a C-shape like Japanese beetle grubs. The adults are velvety chestnut-brown, nearly 1/2 inch long, resembling Japanese beetles. Control them by handpicking and applying beneficial nematodes to the soil. For long-term control, apply milky spore disease powder to the soil.

Dogwood twig borer is a white-bodied, brown-headed larvae. Preventive measures are the best control for these pests like avoiding wounding the trunk with lawnmowers, string trimmers, or pruning equipment because these injuries provide an easy entrance for borers. If borers do strike, try cutting them out of the trunk with a sharp knife. Remove and destroy seriously infected trees.

These symptoms indicate Root-knot nematodes. Prevent root-knot nematodes by applying chitin or introducing parasitic nematodes to the soil before planting. Solarizing the soil also helps in preventing root-knot nematodes. Adding lots of compost to the soil will encourage fungi that attack nematodes.

Leaves covered by small bumps are caused by scales. These insects often feed on the undersides of the leaves. Scrape off minor infestations with your fingernail. Prune out badly infested growth, or use a soft brush and soapy water to gently scrub the scales off the stems. Control scales by spraying insecticidal oil during the growing season.

Pale, silvery leaves, and petals are caused by thrips. They hide under leaves and inside flowers. Severely infested plant parts should be pruned off and destroyed. Control thrips by introducing lady beetles or lacewings. Insecticidal soap helps in severe infestations.

Most likely cause for these symptoms is a fungal disease - Anthracnose. Keep plants dry when watering to prevent spread. Spray plants with copper when the first fruit develops if you have had problems in the past.

Bacterial disease Crown gall causes wartlike swellings on stems of viburnum. Gall bacteria are introduced into shrubs that are vulnerable due to wounds. If the plant is only slightly infected, prune off diseased growth. Destroy severely infected plants and avoid replanting viburnums or any susceptible plant species in the same spot.

Your plants might be suffering from fungal leaf spots. Spots may enlarge rapidly, especially in wet weather. Destroy infected leaves or plants. Spray plants with sulfur to prevent the disease from spreading, especially if the weather is wet. Prevent problems by thinning plants to provide good air circulation.

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. Any commercial fungicidal spray will protect your plant from further infections.

Likely cause for these symptoms is a fungal disease - Rust. Provide good air circulation around plants by thining them. Avoid making leaves wet when watering. All infected leaves should be removed. Spray leaves with sulfur early in the season to prevent rust or to treat mild infections.

Small rodents gnaw the bark off trunks, causing injury that allows disease organisms to invade. Rake mulch away from tree bases during the winter; keep the area clear of weeds and grass, and wrap the trunk base with a guard of 1/4-inch hardware cloth.

Urination by dogs may discolor foliage and even kill branches. Spraying foliage with an anti transpirant gives some protection. Screen the plants or spray with an aerosol pet repellant.