Why Are My Tomato Leaves Turning Yellow?
Understanding the causes of yellowing leaves and how to help your plants thrive.
2026-01-13
As the summer sun warms the garden, I often find myself checking on my tomato plants. A gentle breeze rustles the leaves, but sometimes I notice a troubling sight: yellowing leaves. It’s a common concern, and understanding the cause can help keep your plants healthy.
Yellow leaves can signal a few different issues. One of the most common reasons is nutrient deficiency. Tomatoes are hungry plants, and if they’re not getting enough nitrogen, phosphorus, or potassium, their leaves may start to yellow. A soil test can help you understand what nutrients your soil might be lacking.
Another reason for yellowing leaves is overwatering. Tomatoes prefer their soil to dry out a bit between waterings. If the soil stays too wet, it can lead to root rot, which affects how well the plant can absorb nutrients. Make sure your pots or garden beds have good drainage and check the moisture level before watering.
Pests can also be culprits. Aphids, spider mites, and whiteflies can sap the energy from your plants, causing leaves to yellow. Regularly inspect the undersides of leaves and along stems for any signs of these little critters. If you find them, a gentle spray of water or a soap solution can help manage the problem.
Lastly, consider the weather. Extreme temperatures, either too hot or too cold, can stress your plants and lead to yellowing leaves. If you notice this happening, providing some shade during the hottest part of the day or covering them during unexpected cold snaps can help.
To summarize, here’s a quick checklist to help you troubleshoot yellowing tomato leaves:
- Check for nutrient deficiencies with a soil test.
- Ensure proper watering practices; let soil dry between waterings.
- Inspect for pests and treat as needed.
- Monitor weather conditions and protect plants from extremes.
Taking these steps can help restore your tomato plants to health and ensure a bountiful harvest. Remember, every little effort in the garden brings its own rewards, and watching your plants thrive can be a wonderful joy.