Your tomato plant leaves are likely curling due to hot temperatures or a lack of water. Nutrient deficiencies can make leaves curl as well. Too much nitrogen from fertilizer can also cause tomato leaves to curl and produce thickened leaves. Pests and diseases, like curly top virus, can also result in your tomato plant’s leaves curling up. There are many ways to fix this issue. First, you must identify the exact cause of leaf-curling. After that, set up shade cloth, water more often, or fix nutrient problems to return your tomatoes to health.
Table of Contents
5 Reasons Why Your Tomato Plant’s Leaves are Curling
Growing tomatoes only to see the leaves begin to curl can be very frustrating. However, understanding the problem is the first step toward correcting it. Take the time to identify the cause of your tomato curling leaves. Here are the top reasons your tomato has curling leaves.
Tomato leaves often start to curl as temperatures climb in the mid-summer. The edges of the leaves will roll upward to help the plant cope with the heat stress. Tomato plants thrive in temperatures between 65–85°F (18–29°C). Anything higher than that results in stress from the heat. Watering can help your plants better cope with high temperatures from the sun. The leaves may still curl though. Luckily, the curling leaves do not impact tomato yields.
Lack of Water
The leaves on your tomato plants may curl up if they don’t get enough water. Tomatoes need 1 inch (2.5 cm) of water per week to thrive. Increase the watering amount to 2 inches (5 cm) per week during hot weather. Aim to give your plants about 1/2 to 3/4 gallon of water (2–3 liters) daily to hit those targets. Otherwise, the leaves may curl to help the plant stay alive during drought conditions. Just be careful not to overwater your tomatoes.
Nutrient deficiencies cause tomato leaves to curl up. Calcium deficiencies often result in the new leaves curling inward. Then, the leaves form a parachute shape as they grow. You must resolve this problem before the fruit sets. If you don’t, blossom end rot will ruin your tomato harvests. Regular applications of agricultural lime can help. But you can also reverse the issue by using this organic fertilizer monthly to feed your tomatoes.
Too Much Nitrogen
Too much nitrogen results in the leaves curling into little rolls. The surface of the leaf also turns a dark green color and thickens. The excess nitrogen will force the plant to focus on vegetative growth. This could impact your harvests if you keep applying nitrogen. So, hold back on the fertilizer until the blossoms set fruit. Then, resume your monthly fertilizer applications.
Pests and Disease
Pests and disease often result in leaves curling and even dying altogether. These problems usually go hand in hand, too. Curly top virus is the most likely culprit. This disease occurs as the Beet Leafhopper feeds on the plant and infects it with the virus. The leaves start to thicken, and then curl up and die. Unfortunately, plants affected by this virus do not recover. You must remove them and start over. Put the new plants under a row cover to keep the pests out.
Can You Fix Tomato Leaf Curl?
It’s usually possible to resolve tomato leaf curl, especially if you catch the problem early. You must find the underlying cause first though. Leaves curling due to high temperatures may need a shade cloth. Alternatively, your plants might just need more water.
- You can usually fix tomato leaf curl, especially when you catch it early.
- It’s necessary to find the cause before you can fix the problem.
- Curling leaves caused by high temperatures will benefit from this shade cloth or more water.
- Curly top virus is the only exception—You cannot save plants affected by this virus.
- You must plant new tomatoes under a row cover to get a harvest for that year.
Curly top virus is the only exception. You cannot save plants affected by the virus. Instead, you need to replant your tomatoes under a row cover. Plants placed in an open garden will just get the virus again once the pests return.
How Do You Treat Leaf Curl on Tomato Plants?
The treatment for leaf curl on tomato plants depends on the cause. Too much heat? Add a shade cloth or water more often. Not enough water? Increase your watering frequency and/or amount.
- Your approach to treating leaf curl tomato plants depends on the cause.
- Resolve high temperatures by adding a shade cloth or watering your plants more.
- Plants without enough water just need you to give them more water overall.
- It’s possible to resolve nutrient deficiencies with agricultural lime or a balanced fertilizer.
- If your plants suffer from excessive nitrogen, hold back on the fertilizer until the fruit sets.
Plants with nutrient deficiencies may need agricultural lime or a balanced fertilizer. Leaf curling caused by excessive nitrogen requires you to hold back on the fertilizer until fruit sets, however. Curly top virus is the main exception. You cannot save plants affected by this virus.
Why are the Leaves of Your Tomato Plant Curling?
Curling tomato leaves typically occur due to the following five reasons.
- Exposure to high temperatures.
- Not getting enough water.
- A lack of the right nutrients.
- Too much nitrogen in the soil.
- Development of pests and disease.
Watch for leaf curl as your plants grow. Then, jump into action as soon as you spot the problem developing. Your quick response will help your plants recover faster, so you can still enjoy a big tomato harvest.