Why Do Pepper Plants Lose Their Leaves? (Are They Dead?)


If your pepper plants are losing their leaves, you are probably wondering why it is happening and how you can stop it.  I did some research to find out some probable causes and solutions for this issue.

So, why do pepper plants lose their leaves?  Pepper plants leaves may fall off or have holes due to an infestation of pests, such as Tomato Hornworms or Colorado Potato Beetles.  If the leaves get spots before falling off, the problem is likely bacterial leaf spot.  If the leaves turn yellow before falling off, the problem could be improper watering or nutrition. 

Of course, there are other less common reasons that a pepper plant may lose its leaves, which we will also discuss.

Why Do Pepper Plants Lose Their Leaves?

One common cause of pepper plants losing their leaves is the appearance of garden pests.  Sometimes, it is difficult to see them on your plants or to catch them in the act, but they may be present nonetheless.

Pepper Plants Losing Their Leaves Due To Pests

Two common pests that attack the leaves of pepper plants are the tomato hornworm and the Colorado potato beetle.  Both of these insects can cause the appearance of fallen leaves on pepper plants, and both can do severe damage to one or more plants in your garden.

Tomato Hornworm

According to the University of Minnesota Extension, tomato hornworms are large caterpillars with a tail that looks like a horn (though they cannot sting or jab you with it).  They can measure up to 4 inches in length!

tomato hornworm
Tomato hornworms can totally defoliate pepper plants in one night!

Small tomato hornworms are yellow or white, while larger ones are green with white “V” shapes on their bodies.  Once they turn green, they can more easily blend in with the leaves of the plant they are eating, until it is too late!

Tomato hornworms feed exclusively on plants in the nightshade family.  This means that they eat common garden favorites such as peppers, tomatoes, eggplant, and potatoes.

Tomato hornworms chew through leaves, starting at the top of the plant.  Their activity sometimes gives the appearance of otherwise green and healthy leaves with holes in them.

If the hornworm chews close to the base of a leaf, the leaf may fall off, making it appear that the plant is dropping healthy green leaves.  Tomato hornworms even attack fruit in some cases!

Tomato hornworms can work quickly and can even completely defoliate a plant.  This means eating or cutting off all of the leaves, so that the plant is either dead or unable to recover quickly enough to produce fruit.

You might see dark green or black droppings as the hornworm feeds, which can alert you to their presence in your garden.  Pick any hornworms you see off of your pepper, tomato, eggplant, and potato plants and crush them or drop them in soapy water to kill them.

If you also have problems with worms on tomato plants in your garden, check out my article on what kind of worms eat tomato plants.

You can also check out this article on tomato hornworms from the University of Minnesota Extension.

Colorado Potato Beetle

The Colorado potato beetle is an oval-shaped pest that is 3/8 of an inch long.  It has a yellow-orange lower body and wing covers that are yellow with black stripes.  The females lay orange-yellow eggs on the bottom of leaves.

potato beetle
Colorado potato beetles are another pest that can do serious damage to a pepper plant’s leaves.

When they first hatch into larvae, Colorado potato beetles are red with black heads.  The larvae have two rows of black spots on each side of their bodies.

Colorado potato beetles feed on plants in the nightshade family, including peppers, tomatoes, eggplants, and potatoes.  They first emerge in spring when potatoes begin to grow.

Colorado potato beetles feed on the leaves of plants.  They can completely defoliate plants, much like tomato hornworms.

Their activity may create the appearance of leaves that have holes in them, or leaves that have fallen off if chewed through at the base of the leaf.

Colorado potato beetles are resistant to most pesticides.  Choose early-maturing varieties of peppers to help your plants to get strong enough to survive an attack.  You could also try buying some ladybugs and releasing them into your garden, since they are predators of the Colorado potato beetle.

For more information, check out this article on Colorado potato beetles from the University of Minnesota Extension.

Pepper Plants Losing Their Leaves Due To Bacterial Leaf Spot

Bacterial leaf spot, as the name suggests, will lead to spots on the leaves of your pepper plants.  However, the appearance of the spots will depend on the age (location) of the leaves.

The older leaves (lower leaves) on the pepper plant will develop small spots that look like pimples.  The younger leaves (higher leaves) on the pepper plant will develop small water-soaked spots.

Over time, the spots get larger, especially during warm, humid weather.  The spots become tan or gray in the center, with dark borders.

Eventually, the leaves will turn yellow or brown and then fall off.  You may also see spots or lesions developing on the stems of your pepper plant.  The fruit itself may get small, rough spots that are raised, but these do not affect the quality, and you can still eat the peppers.

Bacterial leaf spot is spread by splashing water from rain or when you water your plants.  It can also spread if you touch an infected plant and then touch other plants (it can also affect tomatoes, so watch out for cross-contamination!)

The disease can survive the winter in soil or in the remains of plants, so be careful about composting plants that were infected!

Your best bet to avoid bacterial leaf spot is to choose resistant pepper varieties to plant.  Also, avoid watering from overhead, so that you prevent wet leaves and splashing, which can allow the disease to spread more easily.

For more information, check out this article on bacterial leaf spot from the University of Maryland Extension.

Pepper Plants Losing Their Leaves Due To Improper Watering Or Nutrition

If there are no obvious signs of pests or diseases affecting your pepper plants, then they could be losing their leaves due to under watering, over watering, or improper nutrition.

Under Watering Pepper Plants

If your pepper plants are exposed to hot and dry weather, the leaves will curl and wilt.  This is because the plant is trying to avoid loss of water of water by minimizing the leaf area exposed to the sun and wind.

Eventually, the leaves may fall off if the plant experiences a severe lack of water due to drought or neglected watering.  Usually, the leaves of an under watered pepper plant will wilt and become dry first, then turn crispy and brown, and then fall off.

To avoid this, be sure to check the soil with your fingers regularly.  If it feels dry to the touch, give your plants a nice deep drink of water.

If your soil seems to dry out quickly, water in the morning, when the sun is not so hot and evaporation will not be so quick.  You can also put down a layer of mulch to prevent evaporation.  If you struggle with keeping your soil wet, check out my article on how to treat dry soil.

Over Watering Pepper Plants

Over watering your pepper plants is another way to cause the leaves to fall off and eventually kill the plant.  Many beginner gardeners are guilty of this, in effect “killing their plants with kindness”.

watering can
Be careful not to over water your pepper plants – the soil should not be constantly soggy!

Over watered pepper plants may show some of the same symptoms as under watered pepper plants.  However, the cause is completely different.

When you over water a pepper plant, it can suffer from root rot.  This weakens and destroys the root system so that the plant cannot absorb water from the soil.

If severe enough, the plant will start to suffer from a lack of water, even though there is plenty of water in the soil.   As with under watering, the leaves will eventually shrivel and fall off.

For more information, check out my article on over watering your plants.

Nutrient Deficiencies or Imbalances In Pepper Plants

If your pepper plant has either too much or not enough of a given nutrient, it can cause problems including loss of leaves.

For example, it is possible to hurt your plants by over fertilizing, either by using more than the recommended amount or adding fertilizer when none is needed.  Excessive nitrogen can cause leaves to get brown scorch marks and fall off.

For more information, check out my article on over fertilizing your plants and my article on low-nitrogen fertilizer.

It is also possible to add too much of a nutrient such as calcium (due to excessive lime) or magnesium (due to a heavy hand with Epsom salt).

Before you add anything to your soil, get a soil test to see the pH and nutrient levels of your soil and adjust accordingly.  For more information, check out my article on soil testing.

If a soil test does reveal a nutrient deficiency in your soil, then that is a likely culprit for your pepper plant’s leaves turning yellow and falling off.  The location of the first yellow leaves (top or bottom of the plant) can also give you hints as to which nutrient is deficient.

For more information, check out my article on identifying nutrient deficiencies in plants.

Pepper Plants Losing Their Leaves Due To Other Causes

There are a few other reasons that your pepper plant may lose its leaves, all of which have to do with stress on the plant.

Transplant Shock

Transplant shock is one big reason that a young pepper plant can lose its leaves.  After growing comfortably inside for weeks, it is a big shock to a pepper plant to be moved outside into the garden.

There is the change in sunlight, air temperature, soil temperature, humidity levels, and watering schedule.  All of this stress can cause a pepper plant to drop some of its leaves.

For more information, check out this article on growing peppers from the University of Massachusetts at Amherst.

Extreme Temperatures

Extreme cold, especially a frost, can cause a pepper plant to lose its leaves, and it can even kill the plant.  Use cloches, row covers, or soil insulation to protect your plants from cold.

frost
A frost can damage the leaves of pepper plants, causing some to fall off.

For more information, check out my article on how to protect your plants from cold and frost.

Sunlight

Ideally, pepper plants want to receive 6 hours of sunlight per day.  More than this could make the leaves dry out and cause the symptoms of a lack of water, as mentioned above.

sunlight through forest
Peppers want 6 hours of sunlight per day, but too much can be a problem, especially if your soil dries out easily.

Conclusion

By now, you should have a better idea of what is causing the leaves to fall off of your pepper plant.  You might also have some new information to help you combat the problem in the future.

I hope you found this article helpful – if so, please share it with someone who can use the information.  If you have any questions or advice about pepper plants losing their leaves, please leave a comment below.

jonathon.david.madore

Hi, I'm Jonathon. I’m the gardening guy (not guru!) who is encouraging everyone to spend more time in the garden. I try to help solve common gardening problems so that you can get the best harvest every year!

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