Why chili plant leaves curl like this is explained at FarmerJer.com.

Why Chili Plant Leaves Curl (With 6 Easy and Fast Solutions) 

Have you noticed that your chili plant leaves curl at the edges? If you’re looking for a solution to your problem, this article will give you the answers you need to help save your chili plants. 

First, let’s state why the leaves of your chili plants are curling up. 

  1. Poor Watering Methods 
  2. Bad Lighting
  3. Cold
  4. Overheating 
  5. Nutrient Issues
  6. Pests and Diseases 

These are the main reasons why leaf curl is present in your chili plants. Be sure to note them down.

This article will give you new information on why the leaves of your chili plants are curling. The information will also apply to pepper plant leaves curling down, as the causes are typically similar, if not the same. You’re welcome to keep reading and find out how to save your chili plants. 

Why Chili Plant Leaves Curl (And Solutions For Each) 

A sign of abnormal reaction from your chili plants is a cause for concern. The plant may react this way due to poor conditions or inefficient resources. Chili plants will germinate between ten days and five weeks, and leaves will sprout. 

If you notice any leaf curling, keep reading for reasons and the chilli leaf curl treatment that corresponds to the cause. 

Poor Watering Methods 

Chili plants are, quite frankly, extremely fragile, especially during the seedling stage of growth. It is common knowledge that plants in the seedling stage may require more water. It exudes succulents since it can naturally retain water. 

Nevertheless, while new gardeners may try not to overwater their chili plants, they may accidentally underwater their chili plants causing them stress. 

When the plant is stressed out, it may turn to leaf curling. It is whereby the plant will roll its leaves, forming a tube-like shape. 

Overwatering may also cause leaf curling. The chili plant seedlings are not used to growing in harsher conditions. Thus, their root systems are not well developed. If you are overwatering, your chili plant will also show signs of leaf curling. 

When it comes to underwatering, in terms of solutions, increase the amount of water you are giving your plant. A good rule of thumb is to check for moisture in the soil, around 2 inches. 

If the soil is wet, your plant has had enough; if, however, the soil is dry, a little more water can go a long way. When it comes to overwatering, reduce the amount of water you give your plant. 

When the chili plant is slightly on the verge of wilting, you can start watering it carefully to help it get back on top of things. 

Bad Lighting 

The leaves will curl up when you expose your chili plant to too much lighting. Believe it or not, this is because your chili plant is trying to shade itself. 

Leaf curling not only involves curling up into a tube but also showing the underside of the leaves. When leaf curling occurs, your chili plant is trying to protect the green plant tissues in charge of photosynthesis. 

Photosynthesis is the biological process through which plants manufacture their food. Light is one of the resources that plants use to manufacture their food. However, too much of it can be deadly to your chili plant. 

When there’s too much lighting, your chili plant curls up to reduce the transpiration rate. Transpiration is the rate at which plants lose water. It means your chili plant is losing more water than it can. 

From a more biological perspective, the osmosis and transpiration rate is not in balance. The rate of osmosis is higher than the rate of transpiration, which causes your chili plants’ leaves to curl. 

The best solutions to curb this problem are:

Cold

Why chili plant leaves curl in the cold is explained at FarmerJer.com.
You can see the leaves have curled in the cold. I took this picture in my backyard, the first snow of the year. It’s been below zero at night for about three days, and the curl has worsened daily.

I can tell you from experience that chili and pepper plants don’t like getting cold. They are quite similar to tomatoes in this respect. Cold temperatures will cause the leaves to curl, similar to overheating but without the signs of wilt.

I recommend keeping your chili or pepper plants at room temperature; they will like it up to about 35 degrees Celsius (95 Fahrenheit). My plants will tolerate the hotter summer weather, but watering is crucial in warmer or hot weather.

Pro-Tip: Transfer your peppers and chili plants into self-watering pots and bring them indoors for the winter. Give them light, and don’t put them too close to drafty windows. If you want to use a window, I recommend putting a plastic barrier over it about an inch away from the glass. Something as simple as plastic wrap and tacks will work if the window is set into the wall. This air barrier will hold the cold in place and allow light to pass through. The only issue you have to watch for is mold, so you can add a couple of those silicon packets you get when you buy electronics. Add the packets to the window sill before putting up the vapor barrier, and they will help keep humidity in your vapor barrier lower, decreasing the chance for mold to start.

Overheating 

The average temperature that a chili pepper can flourish in is between 40 to 80°F. When temperatures cross this mark, they, in turn, cause the leaves to start curling. 

Leaf curl due to overheating is a result of the rate of transpiration. The chili plant will release much more water than usual because of the high temperatures in its microclimate. 

The leaves will then start to curl, trying to reduce the size of exposure. Transpiration depends on leaf size and how much of the leaf is exposed to outliers or external influences. 

As such, the chili plant will curl to reduce the size of exposure. It is its natural way to reduce the rate of transpiration. Eventually, your chili plants may see no need for curled leaves. 

It will then decide to drop them. It is a biological process known as abscission. 

A solution to this problem would be to regulate the temperature in your garden’s microclimate. It should help reduce or even increase the temperatures to an acceptable range. 

Chili plants are infamous for being fragile. Whether germinating, seedling, or mature plants. Temperatures must remain agreeable to the plant and constant. 

Nutrient Issues

Sometimes chili or pepper plant leaf problems like curling can result from a nutrient deficiency. I’ve seen pepper leaf curl happen for this exact reason. Typically, you won’t see curling if a nutrient is in over-supply. However, you might see curling if a nutrient like calcium is deprived. Similarly, you might encounter chili or pepper leaves curling up and turning yellow. Again, these issues can be the result of nutrient problems.

To solve nutrient issues with peppers, I like to start with a good organic soil mix for growing vegetables. Next, I’ll ensure that I add a touch of peat moss and 2-year-old compost into the soil. I compost myself with table scraps and cuttings from my vegetable garden. I like using a composter and ensure I only put ‘clean’ compost into the bin, so it’s safe to use in the following years on my vegetables.

Pests and Diseases 

It is, by far, one of the most common and easily noticeable causes of leaf curling. It is because leaf curling is but one of the symptoms caused by pests and diseases. 

Here are the pests and diseases that cause leaf curling in chili plants. 

  • Beet Curly Top Virus (BCTV) 

It causes the leaves to curl up and stunts growth in the chili plant. Moreover, it causes yellowing in the plant. It is also known as chlorosis. 

You may also notice that the leaves have a leathery texture to them. 

You can control this virus by removing infected plants from the garden. The virus is easily transmitted. Removing the infected plants should keep the rest of the plant community safe. 

  • Gemini Viruses 

This virus causes curling, stunting, and twisting of the chili plant leaves. Furthermore, the leaves and the fruits become distorted. It makes them inedible and less beneficial. 

You can solve this problem by removing the infected plants. Whiteflies quickly spread the Gemini viruses. You could also try crop rotation; however, it might be challenging to control the insects. 

  • Chili Leaf Curl Virus 

This virus is known to attack chili plants and tomato plants. As the name suggests, it is a leaves-curling virus. Another symptom is stunted plant growth. 

You cannot do much because a vector also transmits this virus. This vector is also the whiteflies. The best you can do to save your plants is to remove the infected plants. 

  • Green Peach aphids or plant lice 

These aphids have a light green color and soft bodies. You can also find them on the underside of the leaves or the stems. 

They damage the chili plants by excreting a sticky liquid known as honeydew. It creates multiple spots on the leaves. 

The honeydew spots create a breeding ground for a black fungus or a sooty mold. This fungus or mold will then grow on the honeydew spots. 

This fungus will then cause leaf curling on your chili plants. They can also cause stunting or leaf distortion. 

Because aphids reproduce at an astronomical rate, I recommend using an insecticide to stop their multiplication. 

  • Thrips 

They are most commonly known as vectors for the tomato spotted wilt virus. They do, however, cause leaf curling in chili plants. 

Thrips cause the leaves to distort and curl upwards. The leaves will form a boat shape. Because the leaves are curled, they will expose the underside of the leaves. 

The underside will then develop a silvery sheen, turning to bronze in time. Thrips are tiny and hard for the naked to see. They reproduce every two weeks, and it may be hard to control them. 

The best method is using an insecticide. You can also use biological methods such as predatory mites or ladybugs. 

Leaf Curl FAQs

How do you treat leaf curling?

It is essential to determine what is causing the leaf curl and use the appropriate solutions for treatment. Causes such as lighting, overwatering, or pests are all potential contributors. They each have their solutions to control the leaf curling problem. 

How do I stop your chili plant leaves from curling?

You cannot stop your plants from curling. You can ensure that your chili plants are growing in the right environment and in the right conditions. Chili plants are known to be fragile and quite fickle. 

What causes leaf curl?

Leaf curling is caused by numerous factors, such as overheating, lighting, overwatering, underwatering, pests, and diseases. All these factors play a role in your chili plant’s leaves curling up and dying out. Nevertheless, there are successful solutions to the problem.

  1. Dave Dewitt, Paul Bosland, The Complete Chile Pepper Book: A Gardener’s Guide to Choosing, Growing, Preserving, and Cooking (London: TimberPress,2009)
  2. Khan AJ, Akhtar S, Al-Zaidi AM, Singh AK, Briddon RW. Genetic diversity and distribution of a distinct strain of Chili leaf curl virus and associated betasatellite infecting tomato and pepper in Oman. Virus Res. 2013 Oct;177(1):87-97. doi: 10.1016/j.virusres.2013.07.018. Epub July 30, 2013. PMID: 23911631.
  3. Sayed Sartaj Sohrab, Molecular diagnosis of begomovirus associated with Chilli leaf curl disease in Jeddah, Saudi Arabia, Saudi Journal of Biological Sciences, Volume 27, Issue 11, 2020, Pages 3060-3064, ISSN 1319-562X, https://doi.org/10.1016/j.sjbs.2020.09.009.
  4. Keita Goto, Shin Yabuta, Peter Ssenyonga, Shotaro Tamaru, Jun-Ichi Sakagami, Response of leaf water potential, stomatal conductance and chlorophyll content under different levels of soil water, air vapor pressure deficit and solar radiation in chili pepper (Capsicum chinense), Scientia Horticulturae, Volume 281, 2021, 109943, ISSN 0304-4238, https://doi.org/10.1016/j.scienta.2021.109943

Scroll to Top