How to Troubleshoot Tomato Plant Problems


It's wonderful to grow plump and juicy tomatoes at home instead of buying imported produce from your grocery store. Occasionally though, problems may arise that can affect your tomato harvest. These problems may be because of how you water your plants, or they may be connected to insect pests or diseases. Whatever the underlying problem, troubleshoot your plant to identify the issue and fix your tomato crop.

Step 1

Water the tomatoes if the plant's foliage appears wilted. North Carolina State University recommends irrigating your tomato garden once a week, using enough moisture to thoroughly soak the soil to a depth of 8 inches. To conserve soil moisture, apply a layer of mulch around the tomato plants during the summer.

Step 2

Fertilize the tomato plants if growth appears slow or if fruit appears stunted. Proper fertilization encourages vigorous and optimal growth rates. West Virginia University suggests watering newly planted tomatoes with a homemade fertilization solution made by combining 1/2 cup of 5-10-10 fertilizer in 2 gallons of water. Fertilize again once the tomatoes produce their first set of fruit.

Step 3

Inspect the plant for bugs. If you're watering and fertilizing but the plant still appears stunted or wilted, or if it begins turning yellow or is marked with bites or holes, bug are most likely the culprit. Dozens of different pests may attack the tomato plant, including the tomato fruitworm, tomato russet mite and whiteflies, according to the University of California. Control and eradicate bugs by treating your tomatoes with a pyrethrin-based insecticide or an insecticidal soap. Only spray your plant if more than 50 percent of its foliage is infested with bugs.

Step 4

Look at the tomato plant's stems and leaves for black, brown or yellow spots, or colored dust. Such spots or dust signify a fungal disease like powdery mildew, rust or blight. These weaken the plant and kill it if left untreated. Reduce fungal disease risks by only watering your tomatoes at their base so the foliage doesn't get wet. If the plants contract a disease, spray them with a vegetable fungicide formulated with fixed copper or sulfur.

Things You'll Need

  • Water
  • Mulch
  • Fertilizer
  • Insecticide
  • Fungicide


  • American Tomato Cooperative Extension Sevice: The Complete Guide to Growing and Using Tomatoes; Robert Hendrickson; 2006
  • West Virginia University: Growing Tomatoes
  • North Carolina State University: Growing Tomatoes for Home Use
  • University of California: How to Manage Pests: Tomato
Keywords: growing tomatoes, tomato plant problems, troubleshooting tomato plant

About this Author

Josh Duvauchelle is an editor and journalist with more than 10 years' experience. His work has appeared in various magazines, including "Honolulu Magazine," which has more paid subscribers than any other magazine in Hawaii. He graduated with honors from Trinity Western University, holding a Bachelor of Arts in professional communications, and earned a certificate in applied leadership and public affairs from the Laurentian Leadership Centre.