What to do when tomato plants leaves turn yellow

Yellow leaves on tomato plants can be a sign of a variety of problems, from over-watering to insect infestations to nutrient deficiencies. Here are some steps you can take to diagnose and treat your yellowing tomato plants.

Step 1: Check for Over-Watering

One common cause of yellowing leaves in tomato plants is over-watering. Too much water can lead to root rot, which prevents the roots from absorbing nutrients properly. You can check if your soil is saturated by sticking a finger about an inch deep into the soil. If the soil is wet, you should wait to water your plants until the top inch of soil feels dry. Also, make sure your plants have proper drainage and never let them sit in standing water.

Step 2: Inspect for Insect Infestations

Another possible cause of yellowing leaves in tomato plants is insect infestations. Check your plants carefully for signs of aphids, mites, or other pests. You can wipe them off with a damp cloth or spray them with an insecticidal soap. Keep an eye on your plants to make sure new infestations don't appear.

Step 3: Check for Nutrient Deficiencies

Tomato plants require a variety of nutrients to grow and produce fruit. If your plants are not getting enough nutrients or are unable to absorb them properly, their leaves may turn yellow. Check your soil pH, as tomato plants prefer a slightly acidic soil pH of between 6.0 and 7.0. If your soil is too alkaline, add sulfur or ammonium sulfate. Also, make sure your plants are getting enough nitrogen, phosphorus, and potassium by fertilizing them regularly with a balanced fertilizer.

Step 4: Prune Your Plants

If your plants are still yellowing despite following the above steps, you may need to prune them. Remove any yellow leaves or branches, as they are likely damaged and not contributing to the plant's health. This will help your plants focus their energy on healthy growth and fruit production.

Step 5: Seek Professional Help

If you have tried all of the above steps and your plants are still struggling, it may be time to seek professional help. Contact your local horticulture extension office or a professional landscaper who can diagnose the issue and recommend appropriate treatments.

Overall, yellow leaves on tomato plants can be a sign of a variety of problems, but with careful attention and diagnosis, you can address the issue and get your plants back on track to producing healthy and delicious fruit.