Why do tomato leaves curl up?

Author: Cornell Kub  |  Last update: Monday, June 9, 2025

Heat and low moisture can cause the edges of the tomato leaves to die back, then twist and curl. Hot dry weather may also cause a symptom called physiological leaf roll. This is a self- defense response, where leaves and leaflets curl slightly to prevent further water loss (Fig.

How do you fix leaf curl on tomato plants?

Management strategies for physiological leaf curl include:
  1. Select varieties less prone to leaf curl.
  2. Maintain adequate soil moisture.
  3. Avoid excessive fertilizer, especially nitrogen.
  4. Prune indeterminate varieties conservatively.
  5. Avoid high temperatures by shading plants, when logistically possible.

Can overwatering cause tomato leaves to curl?

Inadequate watering, over-watering, unstable temperatures, and hormone weed killers are among the main causes of leaf curl. Here we take a look at some of the reasons why your tomato leaves don't look quite as lush and healthy as you'd like.

What are the signs of overwatering tomato plants?

What are the signs of overwatering a tomato plant? Plants looking smaller and less healthy. Soil is saturated for extended periods. Seeds aren't sitting in saturated soil for extended periods. Soil is just as saturated a week after watering. Plants look sickly. Roots don't grow as deep. Root rot/fungal infections.

Should you water tomatoes every day?

Water correctly: Do not overwater. The first week tomato plants are in the ground, they need water every day, but back off watering after the first week, slowly weaning the plants down to 1 to 1.5 inches of water per week.

TOMATO LEAF CURL - 3 Causes and What to Do When Your Tomato Leaves are Curling Up.

How do you tell the difference between overwatering and underwatering tomatoes?

Overwatering tomatoes can lead to yellow and spotted leaves, while underwatering results in wilt and diseased fruit.

Do curling leaves mean too much water?

Plants can also run out of water through overwatering! When a plant is over-watered, its roots rot. They can no longer drink and feed the stems and leaves. And the leaf blades curl up to reduce water evaporation.

What deficiency causes curling of leaves?

Phosphorus deficiency commonly causes older leaves to curl, distort, and remain smaller than normal. Unusually purple leaf veins and tip dieback from phosphorus deficiency. Purpling of leaf undersides due to phosphorus deficiency.

Will leaf curl go away on its own?

Leaf curl disease shows up in spring, does the damage, and then disappears (until next spring). If your trees were infected last spring, they should have completely recovered by mid to late summer. They usually grow lots of healthy new leaves (like the photo below).

How to treat leaf curl?

Leaf curl can usually be controlled satisfactorily by a spray of a suitable registered fungicide at any stage of dormancy. Most effective control is achieved by spraying when the buds are swelling but before they have opened. It's not possible to control the fungus once it's entered the leaf.

What do tomato leaves look like with too much water?

While underwatered foliage will be dry and crispy, overwatered tomato plants will usually have soft and mushy leaves or stems. The issue lies in root health. When you overwater, you limit the amount of airflow around the roots, essentially suffocating them.

How do you treat tomato leaf curl virus?

Management of TYLCV includes reducing viral inoculum by destroying crop residues, using reflective mulches to repel the vector in early stages of crop growth, planting TYLCV-resistant varieties when appropriate, and treating plants with a combination of at-plant, drip injected, and foliar insecticides ( Schuster et al.

Does too much water make tomato leaves curl?

You could be applying too much water, the soil might be poorly drained, or there could be a combination of the two factors. Within a few days of the soil drying out a bit, the leaves should uncurl. At that point, begin to monitor how much water you apply to the soil.

What does a stressed tomato plant look like?

Symptoms on leaves - curling & distortion

Symptoms: upward rolling of the leaves. This is a common occurrence in mid-summer and is associated with high temperatures and moisture stress. Some tomato varieties, including heavily pruned determinate-type varieties, are more prone to leaf roll.

What is good food for tomato plants?

How to Make Tomato Fertilizer by Yourself
  • Matured compost (should make at least half of the final product)
  • Alfalfa dry leaves or pellets (rich in nitrogen)
  • Blood meal (a rich source of nitrogen)
  • Pet and human hair (source of keratin and nitrogen)
  • Crushed egg shells (high in calcium)
  • Bone meal (source of phosphorus)

How do you get rid of leaf curls naturally?

What to Do About Leaf Curl
  1. choose the right variety that matches conditions well.
  2. take the time to build diversity and soil strength.
  3. use mixed, woody mulches to drive a strong fungal network.
  4. don't use artificial fertilisers, manure or other strong food – trees don't need it!

What does nitrogen deficiency in tomatoes look like?

N (nitrogen) deficiency of tomato crop is typically characterizes by older leaves that gradually change from green to yellowish or paler green. These leaves will later become yellow, and under extreme nitrogen deficiency they are likely to become bright white-yellow.

What do curling leaves indicate?

Overwatering can lead to root rot, while underwatering can cause the plant to conserve moisture by curling its leaves. Other factors may include pests (such as aphids or spider mites) damaging the leaves, low humidity, exposure to extreme temperatures or drafts, or nutrient deficiencies.

What do overwatered leaves look like?

1. If a plant is overwatered, it will likely develop yellow or brown limp, droopy leaves as opposed to dry, crispy leaves (which are a sign of too little water). Wilting leaves combined with wet soil usually mean that root rot has set in and the roots can no longer absorb water. 2.

What can I spray to keep leaves from curling?

Leaf Curl, prevention is the only way to deal with it that I know of. I start spraying my trees with Neem oil / Bonide Copper Fungicide mixture when dormant 3 times last spray when the buds start swelling but are still gray colored. Blossom Blight is a problem too, this spray takes care of that too.

What do tomato plants look like when they get too much water?

Barbara Gillette is a Master Gardener, herbalist, beekeeper, and journalist. She has 30 years of experience propagating and growing fruits, vegetables, herbs, and ornamentals. One sign of overwatered tomato plants is drooping stems and foliage.

How often should I water tomatoes?

Soil that contains a lot of sand doesn't hold water well and dries quickly. Because of this, tomato plants growing in sandy soil may need to be watered more often, about every three or four days. Clay soil, on the other hand, holds water well. Plants growing in clay soil usually only need to be watered once a week.

Is Underwatering worse than Overwatering?

Is Overwatering Worse Than Underwatering? Overwatering is as equally lethal as underwatering in plants. The colossal factor is blamed on the length of exposure: the more time the soil was soggy or dry, the more a plant is likely not to survive.

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