You will know underwatering is the problem if your leaves start to yellow on their edges until the whole leaf drops off the plant.įor overwatering problems, remove the layer of mulch covering the soil at the base of the tomato plant and let the soil stay exposed to airflow and sunlight for a few days, trimming the access leaves from your plant. Underwatering your plant can also cause leaves on tomato plants to turn yellow after wilting. However, the excess water in your soil will suffocate roots and cause the root to rot, and as the roots get damaged, the soil has less oxygen available to the leaves hence the tomato plant leaves turn yellow and drop off. To keep the plants happy, gardeners may overwater the plant giving it more water than it needs to avoid the soil drying out. One of the common causes of yellow tomato leaves is incorrect watering, where gardeners may sometimes provide the plant with too much water or too little water. To prevent nitrogen-deficient plants, add earthworm castings, compost, and coffee grounds to boost the soil’s nitrogen level and add a balanced all-purpose fertilizer to your soil at the beginning of a season.Īdd Rockdust in your garden plants to prevent an iron-deficient plant, and you can also add a chelated or a powdered iron supplement in the spring season to correct the soil. Ensure you follow the package instructions and repeat the application if need be. As a result, an iron-deficient plant will develop pale yellow leaves that will drop off eventually, and the tomato plant will be unproductive after the yellowing leaves drop.įor the immediate effect on nitrogen-deficient plants, apply some liquid fertilizer with a high nitrogen value and follow the instructions on the fertilizer package to avoid burning the plant.įor a quick fix on iron deficiency, apply a liquid iron supplement to your tomato plant, which you can spray on the foliage if it’s mixed with water or added to the soil. The yellowing will continue through the leaf veins, and the leaf’s base of the plant will develop a web-like appearance. Once the older leaves turn yellow, the plant will stop growing and producing due to a lack of nutrients.įor Iron Deficiency, when the soil is not providing enough iron to the tomato plant, the youngest leaves start to turn yellow at the bottom of the plant.

Since tomato plants grow very fast, they must have their nitrogen-rich soil for tomato production and optimum plant growth, and if the soil has a nitrogen deficiency, the older leaves will start turning pale yellow. Nitrogen deficiency is among the most common deficiencies, and nitrogen is need for any above-ground plants to flourish. Reasons why your Tomato plants are Turning Yellow When should you stop watering tomato plants? Should I remove yellow leaves on tomato plants? Frequently Asked Questions on the Yellow Leaves on a Tomato Plant.Reasons why your Tomato plants are Turning Yellow.

Tomato seedlings turning yellow