What Is Wrong With My Desert Catalpa?

Are the older leaves turning yellow and wilting, an overall decline in plant vigor is apparent?

Are there any small, round to irregular spots on older leaves?

Have the seedlings collapsed, seeds or shoots may have rotted?

Are the leaves curled and distorted, sticky to the touch?

These symptoms indicate fungal disease Verticillium wilt. Verticillium infects a wide range of plant species. Destroy all infected plants, as there is no cure. Prevent problems by presoaking seed in a 10 percent bleach solution.

Phyllosticta leaf spot causes small, round to irregular spots to form on older leaves. Spots have purple borders and yellow halos. Avoid overhead watering. Apply a fungicide to protect healthy plants.

If you're growing desert catalpa from seeds and you have noticed that the seedlings are falling over and the stems are girdled or rotted at the soil line, the most likely cause is a damping-off disease. Remove and destroy all infected plants. To prevent damping-off let the soil surface dry between waterings, thin seedlings to avoid overcrowding, and do not add nitrogen fertilizers until plants have developed leaves.

Distorted and sticky leaves and stems 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 only with severe infestations.

Mineral deficiencies can cause tip chlorosis or necrosis or cause foliage to discolor, fade, distort, or become spotted, sometimes in a characteristic pattern that can be recognized to identify the cause. When nutrient deficiencies occur, nitrogen and iron are the most commonly seen deficiencies. Apply only the mineral found to be deficient. Excess nutrients, on the other hand, cause symptoms like leaf tip dieback, marginal leaf chlorosis, necrosis (or burn), branch dieback, and pest problems. In this case, you should provide good drainage, and use good practices during fertilization and irrigation.