Why Does My Tulip Tree Leaves Look Unhealthy?

Are the leaves wrinkled and discolored?

Are the leaves yellow and drop early?

Are the leaves yellow and covered with small bumps?

Do the leaves on your tulip tree have a black coating?

Are the trunk and the branches of your tulip tree oozing sap through the lesions?

Do the leaves have spots?

The small green tuliptree aphids can be abundant on the undersides of leaves, secreting copious amounts of honeydew. You can control them by washing them off the plant with water spray. Insecticidal soap should be used with severe infestations. Ladybugs are their natural enemies.

If the leaves are yellow and dropping early, the problem may be the lack of water. This is a common problem on newly planted liriodendron trees as well as established plants that don't get enough water. Avoid this problem by watering well during dry periods and using a thick layer of organic mulch.

Yellow leaves covered by small bumps are caused by scales. These tiny, shelled insects often feed on the undersides of the leaves, causing an unhealthy appearance with yellowish blotches on the upper leaf surfaces. 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.

Black coating on the leaves is caused by a fungus Sooty mold. This fungus grows on honeydew produced by aphids and scales. The black coating doesn't harm the leaves directly but it does reduce the intensity of photosynthesis. Sooty mold is best controlled by dealing with the insects that are producing honeydew. Remove honeydew and sooty mold from the leaves by wiping it with the damp cloth.

Oozing lesion is 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.

Tuliptree spot gall is a fungal disease that causes circular brown or purple spots surrounded by a circle of yellow on the tulip tree leaves. Damaged leaves may fall early. While unsightly, the problem is not serious and is best countered by removing all affected fallen leaves

If the leaves have a powdery white coating on them, the cause is a fungal disease Powdery mildew. Powdery mildew usually appears in damp places. Thin your plants to ensure good airflow. 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.