If your tomato plants are developing yellow or black spots on their leaves, it might be a sign that there's a larger problem at work. And if you don't identify and treat the problem, you might lose your tomato plant---or worse, a whole crop.
Early blight is a fungal infection that produces blackish-brown spots on older tomato leaves. Remove all infected leaves, and plant your tomatoes in a different spot next year---the fungus can continue to live in the soil.
Aphids and Whiteflies
Aphids and whiteflies are common garden pests. Infested plants will have yellowed leaves covered with a sticky substance. Spraying the leaves with a solution of mild, diluted dish soap usually solves the problem.
Named for the fungus that causes it, Fusarium wilt advances up the stem, yellowing foliage and wilting branches as it goes. Remove all infected plants and debris from the garden.
Many tomato varieties are resistant to Fusarium wilt. Check with your nursery to see if they carry Fusarium-resistant cultivars.
Tomato plants need support to keep branches and fruit from trailing on the ground, where they might pick up pests and diseases. Use a stake, cage or trellis to keep your tomato plant upright and healthy.
- Colorado State University Extension: Recognizing Tomato Problems
- Iowa State Extension: Tomato Diseases and Disorders
- You Grow Girl: Start Healthy Tomatoes
tomato plants, tomato diseases, yellow leaves, black leaves, early blight, fusarium wilt
About this Author
Helene Wecker lives and writes in California's sunny East Bay. Her work has appeared in numerous trade magazines, websites, and newspapers including the Chicago Tribune. A professional writer for 14 years, Helene holds a Master's in Creative Writing from Columbia University.