What causes leaf curl on tomato plants can be anything from excessive heat to fungi attacks to certain diseases. Fortunately, this article will teach you all possible problems and their solutions. So read on for some great tips!Curl Leaf on Tomato Plants

What Causes Curling Tomato Leaves?

Curling tomato leaves are caused by difficult growing conditions, excessive pruning, shock following transplantation, weed eaters or even some diseases that tomatoes are prone to. You should not ignore these as they are a sign that something is going wrong and you do not want to ruin the entirety of the crop!

Curled-up leaves indicate something is wrong in the environment or the plant itself. First, examine your tomato leaves closely to determine why they are curling. Lack of moisture, herbicide damage, and diseases are all common culprits.

– Difficult Growing Conditions

Nature can present several challenges to tomato plants as they grow. Generally, the most common cause of tomato leaf curl is poor growing conditions, which is also the easiest to correct. The leading causes of leaf curl are high temperatures, a lack of moisture, and heat stress. The leaf margins roll upwards in excessively hot and dry conditions, and it is more common on the bottom leaves.Nutrient Deficiency of Tomato Plants

Hot and dry conditions, like other vegetables, can cause leaf curling on tomatoes. Plants actively growing and developing fruit have a high demand for water in late spring and early summer. Plants respond to hot and dry conditions by rolling their leaves to reduce the surface area exposed to high radiation.

Lower leaves on a tomato plant are frequently the first to be affected; they may recover if environmental stresses are reduced. However, in some varieties, leaf curling can occur on all of a plant’s leaves and last all season. Leaf curling caused by environmental stresses is not a major concern, but if the stress condition persists, it may eventually lead to blossom end rot fruit and decreased yield.

The reason behind this stress-induced leaf curl reveals that it is a protective mechanism plants use. When the weather is hot and dry, tomato plants cannot absorb as much water as they lose through evaporation. Leaves curl up due to the internal water deficit, and a curled leaf absorbs less sunlight and loses less water. In other words – leaf curling is a self-defense mechanism.

Reducing the environmental factors of stress that causes leaf curl can help prevent the problem. Begin with proper watering techniques. You should try for 1 inch of water per week for tomato plants. If plants do not receive that amount from rainfall, supplement with a hose or drip line that delivers water directly to the root area.

To prevent disease spread, avoid overhead watering. Add a 2.5-inch layer of mulch around tomato plants to reduce soil moisture evaporation.

– Excessive Pruning

While pruning tomato plants can help promote fruit development, removing too much foliage at once can cause problems. As a stress response, the plant curls its remaining leaves after experiencing a sudden loss of energy-generating leaves.

Excessive pruning is best treated by thoroughly watering the plant and allowing it to recover. Allow new leaves to grow. In a few weeks, the plant should be back to normal.

– Shock Following Transplantation

Moving seedlings or young starts into your garden can cause tomato plants to become stressed. Temperature fluctuations and root disturbance caused by transplanting cause some tomato varieties’ leaves to curl up in self-defense.Transplantating Tomato Plants

Within a few weeks, plants often recover independently from leaf curl caused by transplant shock. As your tomatoes settle in, provide plenty of water. To avoid transplant shock in the future, slowly acclimate seedlings to garden conditions before planting and handle the root ball gently. Do your transplanting on a cool, overcast day, or provide temporary shade for your newly transplanted tomatoes with a tarp or other material that will block direct sunlight.

– Herbicide Damage

Your tomato leaves may be curling due to a weed-free lawn – “drift” from herbicides is a common offender. Drift is caused when the herbicide goes off-target. If the wind blows weed killer onto your tomato plants, the chemicals may even kill your tomatoes and will affect foliage growth.

Herbicide-damaged plants have leaves that bend downward and individual leaflets that bend upward in a cup-like shape – this differs from the tightly curled or rolled leaves that result from hot, dry growing conditions.

Herbicide-related leaf curl can also be caused by contaminated compost or mulch. The contamination is caused by long-lasting pasture herbicides such as picloram, clopyralid, or aminopyralid found in commercially available compost materials. When compost is spread throughout the garden, it can affect tomatoes.

There is no cure for herbicide-induced leaf curl, you can take a “wait and see” attitude. Some plants can withstand the effects and produce a crop; others will die if they do not bear fruit. Avoid using weed killers near tomato plants in the future. Know where you get your compost and mulch, and buy from a reputable dealer.

– Diseases of Tomatoes

Though uncommon, some viral tomato diseases may be the cause of curling leaves. If a tomato mosaic virus is to blame, you’ll notice twisting and twining new growth instead of the curled older leaves common in plants stressed by harsh growing conditions. Individual new leaflets are prone to curling.Thrips on Tomato Leaves

Unfortunately, tomato leaf curl viruses are incurable. To help prevent their spread, remove the entire plant from the garden. Do not throw the plants on the compost heap as they are tainted and rather choose newer varieties with virus disease resistance in the future.

Frequently Asked Questions

– Can Tomatoes Recover From Leaf Curl?

Yes, tomatoes can recover from leaf curl and still produce a good crop. You should pull the plant out and start over if you notice curling leaves on new growth. Ensure that the manure or compost you use in the garden is not contaminated.

Irregular irrigation and improper pruning cause the leaf edges to leaf roll inward, sometimes overlapping. This condition may appear serious when most of the leaves on the plant are affected, but it is not permanent. Deep, even watering regularly and careful pruning are the cures. Additionally, it also helps with broad mites.

– What Are the Common Tomato Leaf Curl Disease Symptoms?

The most common symptoms of tomato leaf curl disease are:

  • Small tomato yellow leaves between the veins.
  • The leaves curl upwards and towards the center of the leaf as well and show leaves turning yellow.
  • Shoots shorten in tomato seedlings, giving the young plants a bushy appearance.Yellowing Leaves Between Tomato Veins

– What Are Your Hydroponic Tomato Leaves Curling Up?

Your hydroponic tomato’s leaves are curling up because the leaves of your plant curl up to protect themselves if exposed to too much sun, too hot temperatures or too much wind. Curled leaves are common and will not harm your tomato plant.


Tomato leaf curling is a problem that, in most cases, can be avoided with due care and diligence. Therefore:

  • Give them the right growing conditions to avoid such problems. This includes getting fungus infestation and too much watering.
  • Chemicals from weed killers are also a common culprit that results in tomato leaf curling, so try to cover your plants before blowing those chemicals.
  • Excessive pruning is also something that needs to be avoided to promote healthy growth.
  • If it is a disease, treat promptly and throw away the remnants so as to stop any reinfection.

With these factors in mind, we are sure you will help avoid leaf curling problems in your tomato plants. Happy growing!

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