Why Your Tomato Leaves Are Curling - Backyard Boss
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Why Your Tomato Leaves Are Curling

There’s nothing quite like a fresh-picked tomato still warm from the sun. But have you ever looked at your tomato plant leaves and wondered why they were all curled up? Don’t worry, you’re not the only one! This is a common question among gardeners, and there are several possible explanations.

If you’re curious about what’s going on with your plants, as well as how to fix the problem, keep reading!

Common Causes of Tomato Leaf Curl

If you’re like most gardeners, the sight of tomato leaves curling up is cause for concern. While it’s not always a death sentence, it can be a sign of a problem. Here are some of the most common causes of leaf curl in tomato plants and how to remedy them.

Watering

Watering tomatoes plant in greenhouse garden. Hand with watering can in greenhouse watering the tomato. Close up.
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If you notice that your tomato leaves are beginning to curl up, it could be due to an abundance or lack of water. When plants don’t receive enough water, their leaves will begin to droop and curl in order to prevent further water loss.

If you see curling leaves, check your plant before watering to ensure that the soil is not moist, and the roots are still healthy. If the soil is dry, be sure to give the plant a thorough watering. If the problem persists, you may need to increase the frequency of your watering schedule.

Be aware, too much water is also bad.

Herbicide Damage

Curled tomato leaves
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Herbicide damage can also make leaves curl up, preventing the plant from getting the sunlight it needs to produce fruit. While there are many different herbicides on the market, some work by interfering with a plant’s growth hormones. This disrupts the normal process of cell division and cell elongation, causing the leaves to curl up. In some cases, the leaf may also turn yellow or brown and eventually drop off the plant.

Take a close look at the leaves for signs of injury. In most cases, the damage is not permanent, and the plant will recover once the herbicide is no longer present. However, if the plant is severely damaged, it may not produce fruit for the current growing season.

If you suspect that herbicide damage is causing your tomato leaves to curl up, the chemicals can reach your plants in different ways.

  • Drift: a gardener near you sprayed herbicides and the wind carried the drift to your garden
  • Residue: compost made with hay that has been sprayed with a toxic herbicide
  • You: make sure that you are using the correct amount of herbicide for your plant. Don’t overdo it.

Temperature Extremes

red tomato damaged by disease and pests of fall leaves and fruits of tomato
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If the temperature is consistently hot, dry, and sunny, the leaves will roll up to reduce their surface area and prevent themselves from getting sunburned or drying out. When the temperature drops below 50 degrees Fahrenheit, the leaves will also curl up to try to preserve warmth. In both cases, curling leaves can lead to reduced fruit production.

To help your tomatoes thrive in extreme temperatures, make sure they are getting enough water. Irrigation can help cool down plants during hot weather and help prevent damage. Mulching can also help insulate plants, keeping them warm during cold snaps.

Finally, choose varieties that are adapted to your local climate and make sure they are getting enough sun exposure.

Nutrient Deficiency

compost tumbler turner full with green and brown material
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Curled leaves in tomato plants could be a sign of different nutrient deficiencies, including nitrogen, phosphorus, and potassium. Conversely, too much nitrogen or salt can also cause this problem.

The best way to determine which nutrient is lacking is to take a soil sample and have it tested. Once you know the  lacking nutrient, you can take steps to correct the problem. For example, if the soil is low in nitrogen, you can add compost or other organic matter to improve its fertility. If the problem is due to a lack of phosphorus or potassium, you can apply a fertilizer that contains these nutrients.

Once the deficiency has been corrected, the leaves should begin to uncurl, and the plant will return to normal growth. However, if the problem is not corrected in a timely manner, it can lead to serious problems for the plant, including stunted growth, yellowing of the leaves, and premature fruit drop.

Over-Pruning

person crouched pruning tomato plant
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Pruning is an important part of gardening, but it’s also important to know when and how much to prune. Over-pruning can cause serious damage to your tomato plants! So, if you’re not sure how much is too much, it’s best to err on the side of caution and prune a little less than you think you need to.

If you do find that you’ve over-pruned your plants, there are a few things you can do to help them recover. First, give them plenty of water; the leaves will need extra hydration to recover from the stress of being pruned. You may also want to add some organic matter to the soil to help give the roots some extra nutrients.

Pests

aphids on plant
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Pests can wreak havoc on your tomato plants, causing leaves to curl up and eventually die. Curled leaves are a sure sign that something is wrong with your plant, and if you see them, it’s important to take action quickly.

There are a few different pests that can cause leaf curl in tomatoes, including tomato pinworms, broad mites, and aphids. These pests suck the sap out of the leaves, causing them to curl up and turn yellow or brown. In severe cases, the entire plant may be killed.

Broad mites, in specific, are extremely difficult to see with the naked eye. You can identify them by their unique eggs that resemble transparent glass clustered close together. If you suspect that pests are responsible for the leaf curl on your tomato plants, there are a few things you can do to get rid of them.

First, try spraying the plants with water to knock the pests off. You can also use insecticidal soap or neem oil, which are both effective at killing pests. In the case of broad mites, miticides may help. Finally, make sure to keep your garden clean and free of debris, as this will help discourage pests from taking up residence in the first place.

Viruses

Tomato Virus
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If you’ve noticed that your tomato leaves are curling, it could be due to a virus. There are several different types of viruses that can affect tomatoes, including tomato mosaic virus and tomato yellow leaf curl. These viruses are spread by insects, such as whiteflies, and can cause the leaves of your plant to curl up and turn yellow or brown.

If you think your tomato plants have a virus, there’s, unfortunately, no cure. However, you can try to control the spread of the disease by removing infected plants and disposing of them properly.

How to Grow Tomato Plants

Potted cherry tomatoes plant
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If you’re new to growing tomatoes or have had bad luck in the past, you may be wondering how to get your tomato plants to produce a bountiful harvest. Here are some tips on how to grow healthy, productive tomato plants.

  • Choose the right variety of tomatoes for your climate and growing conditions. If you’re not sure which variety is best for your area, ask at your local nursery or gardening center.
  • Next, plant them in the right location. Tomato plants need full sun to produce well, so pick a spot in your garden that gets at least eight hours of sunlight per day.
  • The soil should be fertile, loose, slightly acidic, and well-drained, as tomatoes won’t do well in soggy soil. If your soil is heavy clay or very sandy, you may want to amend it with some organic matter before planting.

How To Care For Your Tomato Plants

Watering newly planted tomatoes and potted basil growing in a container garden
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Tomatoes are a delicious and nutritious addition to any meal, and they’re relatively easy to grow at home. With a little care and attention, your tomato plants can produce fruit all summer long. Here are some tips on how to care for your tomato plants:

  • Water regularly: Tomatoes need about an inch or 2 of water per week, so be sure to keep an eye on the moisture level in the soil. Water deeply and evenly, taking care not to overwater or allow the plants to dry out. Water in the morning when the sun is not as hot.
  • Fertilize regularly: Tomatoes are heavy feeders, so they’ll need regular fertilization to produce a bountiful crop. Use a balanced fertilizer every 2 weeks to a month, or you can use an organic fertilizer like compost or manure. This will give the plants the nutrients they need to produce plentiful fruit. Just be sure not to over-fertilize, as too much nitrogen can actually lead to fewer tomatoes.
  • Prune regularly: Pinching off the suckers that grow in the leaf axils will help the plant focus its energy on producing fruit, rather than foliage.
  • Stake or cage the plants: As the plants grow, they will need support to keep from falling over. Staking or caging helps prevent damage to the fruits and makes harvesting easier. And, don’t forget, harvest your tomatoes regularly! The more you pick, the more fruit your plants will produce.

Take These Tips To The Garden!

While there can be several causes for curling leaves, most of them are relatively easy to fix so don’t panic! Take a few minutes to read through this article and see if you can identify the cause. And if you have any tips or tricks of your own, be sure to share them in the comments below!

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