What to Do When Your Tomato Plant Leaves Turn Yellow

Yellow leaves on your tomato plants can be concerning, but they are not always a sign of a serious problem. There are a variety of reasons why your leaves may be turning yellow. Here’s what you can do to diagnose the issue and get your plants back to healthy growth.

1. Inspect for pest infestations

Pests such as aphids, whiteflies, and spider mites can feed on the leaves of your tomato plants, causing yellowing or discoloration. Check your plants closely for signs of pests, such as small holes or webs on the leaves. If you do find infestations, use an insecticidal soap or other organic treatment, or consult a professional for help with more serious infestations.

2. Check soil nutrient levels

Another common cause of yellow leaves in tomato plants is nutrient deficiencies. Check the soil around your plants for nitrogen, phosphorus, and potassium levels. Low levels of any of these nutrients can result in yellowing leaves. Consider using a fertilizer to provide your plants with the nutrients they need to grow healthy and strong.

3. Assess watering practices

The amount of water your tomato plants receive can also impact leaf health. Overwatering or underwatering can both lead to yellowing leaves. Ensure that your plants are receiving an appropriate amount of water for their needs. You can check the soil moisture by sticking your finger a few inches into the soil – if it feels dry, it is time to water.

4. Evaluate sunlight exposure

Tomato plants need a lot of sunlight to grow, and insufficient light can result in yellow leaves. Ensure that your plants are getting at least six hours of direct sunlight each day. If your plants are in a shady area, consider transplanting them to a sunnier location.

5. Consider temperature and humidity

If the air around your tomato plants is too hot, too cold, or too dry, it can impact leaf health. Tomato plants thrive in temperatures between 70 and 85 degrees Fahrenheit, with humidity levels between 40 and 70%. If your plants are in a location with extreme temperatures or low humidity levels, consider moving them to a more suitable location.

By identifying the root cause of your tomato plant’s yellow leaves and taking appropriate action, you can ensure that your plants grow healthy and strong. With proper care and attention, you can enjoy a bountiful tomato harvest all season long.