What Does Tomato Plant Leaf Curl Mean?

Tomatoes are an heirloom gardener's best friend. However, there is a world of diseases, deficiencies, and pests to deal with when growing them. Tomato leaf problems are the most frequent in the garden, especially if you are growing non-heirloom varieties. Today, we are going to discuss the handful of tomato issues that can be identified simply by looking at leaf curl on the plants. Leaf curl is not always a bad thing, so we will look at what it means on each part of the plant.

Let's get started.

Leaves Curling Up

Leaves that curl up are very common and won't hurt your tomato plant at all. This type of leaf curl is a response to environmental issues almost 100% of the time. If your plant is being exposed to too much sun, too hot of temperatures, too much wind, or a lack of water, the leaves will curl up to protect themselves. The leaves are like mini solar panels, so when the plant has a sufficient amount of sunlight, they close in order to prevent sunburn on the leaves. This type of curl will go back to normal as soon as the environmental problem goes away.

Leaves Curling Down

When tomato leaves are curling downward, this normally is the result of a lack of nutrients due to root rot. Root rot occurs when overwatering causes the plant to stop water uptake. The roots of the plant will contract and close to halt water uptake to prevent the plant from dying. Eventually, if the plant continues to be overwatered, the roots will rot and the plant will die. The leaf curl happens when because the plant cuts off the water supply until it is safe to drink again. The best thing to do in this situation is to wait for the plant to drink up any water in the soil. Normally, this problem will sort itself out. Preventative measures can be taken next season by adding better drainage to your garden beds.

Leaves Curling on the Bottom

Normally, tomato leaves curling at the bottom of the plant is a sign of a micronutrient deficiency. However, you will normally be able to tell by the yellowing leaves that there is a problem long before any curling occurs. There are a few easy fixes to this issue. Azomite is a clay compound that is packed with minerals and micronutrients that are often washed away in modern soils. Additionally, adding fresh compost or an all-purpose fertilizer will be the perfect soil amendment to get your plants back on track. Compost and Trifecta+ are both incredibly nutrient-dense and can be used without the risk of burning the plants.

Leaves Curling on the Top

If you notice your tomato plants begin to grow in a wiry pattern, if the leaves are smaller and curled, your tomato plant has a disease called curly top virus. This virus is spread by the leafhopper bug, and will only choose one plant to bite. Luckily, this virus will not spread to other plants. Curly top virus stunts the growth of the affected plant. If there is fruit growing, it will be able to reach full maturity. However, after the harvest, it's best to dispose of the plant completely and use that space for a new plant. Sometimes the plant will fight the virus by growing side shoots, and sometimes this can save the plant although the chances are very low. There isn't anything that can be done about curly top, so it's best to plant multiple tomato plants to decrease the chances of losing yield.

Written by - Kaitlynn from MIgardener 

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