Why Does My Linden Tree Look Unhealthy?

Is the foliage yellowing in places and dropping prematurely, growth is slowed?

Does the trunk or the branches sunken areas of dead tissue?

Are the leaves covered with white powder?

Are the leaves curled and distorted?

Are there any irregular galls on undersides of leaves, leaf stalks, and/or new shoots?

Does the trunk or the branches have small holes, limbs die, or break off?

Are the leaves yellow, branches, and leaves are covered with small bumps?

Do the leaves have spots?

These symptoms usually indicate a fungal disease - Verticillium wilt. This soilborne fungal disease makes leaves yellow, wilt, and fall off before the entire branch dies. Avoid planting trees near strawberries, potatoes, tomatoes, and eggplants as they are susceptible to Verticillium wilt. Soil solarization may prevent the disease.

Sunken areas of dead tissue on linden trees are caused by cankers. Cankers can be caused by several different kinds of fungi. Mildly affected plants will recover if you remove and destroy all affected branches. Heavily affected plants can't be cured and you should remove the whole plant. Avoid damaging your plant with lawnmowers, trimmers, or pruning tools because the wounds are the best place for cankers to start.

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.

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.

Linden gall mite is a known pest of linden trees. Monitor for the presence of gall mites by regularly checking the undersides of leaves. In large trees, the damage is often limited and does not require control. Miticides need to be applied protectively as once the mites have entered the leaves, chemical control is ineffective.

Longhorn borers attack linden trees, mining the inner bark and wood of branches and trunk. Prune off borer-infested branches. If you see borer holes in your trees, probe into them with a flexible wire or inject a solution of parasitic nematodes. After treatment, seal holes with putty.

Soft scales often attack linden trees. 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.

Linden trees are known to suffer from Anthracnose or other 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.

If there are small blisters on the woody surfaces the probable cause is a White rot. Also known as sap rot, white rot is a fungal disease that affects the tree during cool and humid weather. Linden becomes prone to white rot during winters, and this fungus attacks those linden trees that have been damaged due to drought. You can control white rot by pruning the affected area, and use fungicidal treatment. Since this disease is caused in cold weather, apply fungicides from spring to late fall.