Nothing is more frustrating than putting in the work to plant and grow peppers, only to see your plants wilting and dying. The question is, why does this happen? More importantly, how can you stop it?
So, why do your pepper plants keep dying? Over watering is the most common reason that pepper plants will wilt and die. Over watering will cause root rot in a pepper plant, and too much water can also wash away vital nutrients in the soil.
Always check to make sure you are watering correctly before doing anything else. Many beginner gardeners will over water pepper plants at first – once per day is probably too much in most areas!
If you know that watering is not the problem, then there are a few other possibilities. First, you should check the basics, such as sunlight, temperature, and soil (pH and nutrients). Then, check to see if any pests are present, such as aphids or cutworms. Finally, look for signs of disease in your plants.
Let’s take a closer look at what kills pepper plants, and how you can prevent this from happening.
Over Watering Your Pepper Plants
Over watering is the most common reason that pepper plants die off. Many well-intentioned gardeners who are growing peppers for the first time will over water. In effect, they are “killing the pepper plant with kindness”.
There is more to watering than just frequency. Let’s start with how to treat the soil to assist in your watering efforts.
How to Improve Soil for Watering
The most important thing to remember is to add organic material to your garden every year. This can be in the form of compost or manure. Both of them should be sufficiently decomposed, to the point where they look similar to dirt (compost will be darker, with a color that is almost black).
For more information, check out my article on how to make your own compost.
Adding organic material to your soil improves drainage. This means that water will not sit for too long in the soil without moving through it. As a result, you will prevent common symptoms of over watering, such as root rot.
As an added benefit, adding compost and manure to your garden each year replaces vital nutrients in the soil. Remember that your plants will use some of this material when they grow, so you need to replace it constantly.
When and How to Water Your Pepper Plants
You should water in the morning, when temperatures are cool and the sun is still low in the sky. This ensures that the water will soak through to the roots before the water evaporates.
When watering, slower is better. Watering too quickly with a bucket will often wash away topsoil and nutrients, which your plants need to survive.
Instead, use a soaker hose to water a plant slowly, or go up and down your rows a few times, using a hose with a spray attachment.
Finally, keep an eye on the pepper plants and the soil itself to tell you when to water. If the pepper plants look fine, they probably don’t need water. For more information, check out my article on over watering your plants.
If the pepper plants start to wilt a bit, especially on a hot day, check the soil. If it feels dry down to a depth of a few inches, you probably need to water.
It is ok to let the soil get dry between watering, since this gives the roots a chance to dry a bit and avoid root rot. If you think you have a problem with dry soil, check out my article on how to treat dry soil.
Check the Environment for Your Pepper Plants
At this point, you are confident that over watering is not the problem that is causing your pepper plants to die. In that case, let’s look at some other common factors that can kill pepper plants.
Sunlight and Temperature
Pepper plants need full sunlight, which means 6 to 8 hours of direct sunlight per day. This means that they should be in the sun most of the day during the summer.
Your pepper plants may be lacking sunlight if they are in a shady location in the garden. In this case, the only thing to do is to cut down trees that are shading them, or plant in a different area next year.
Extreme temperatures can also affect your pepper plants. The ideal temperature is 65 to 80 degrees Fahrenheit (18 to 27 degrees Celsius) during the day.
If temperatures drop below 55 degrees Fahrenheit (13 degrees Celsius) at night, you may begin to see slowing growth. Low temperatures also interfere with a plant’s ability to absorb nutrients.
Remember that a frost will generally kill pepper plants that are not covered. Starting your pepper plants too early or too late in the season can lead to loss of your crop due to a late spring or early fall frost at night.
For more information, check out my article on how to protect your plants from cold and frost.
Soil pH is important for plants to grow properly, since it dictates whether they will be able to absorb nutrients from the soil. An ideal soil pH for pepper plants is 6.0 to 7.0 (slightly acidic).
If the soil pH is too low or too high, certain nutrients in the soil will be unavailable to the pepper plant’s roots. This is true even if there is plenty of the nutrient in the soil!
For more information, check out this article from Research Gate about how nutrient availability depends on soil pH.
To find out if your soil pH is off, you can buy a test kit online or at a garden center. You can also send a soil sample to your local agricultural extension. For more information, check out my article about soil testing.
If your soil pH is within an appropriate range, then another place to look is at the nutrient levels in your soil. This can also be determined by a soil test (see above).
As mentioned earlier, adding compost or manure to your garden is one of the best ways to add nutrients to the soil, while also providing new organic material.
You can also use chemical fertilizers, which can supplement the big three nutrients (NPK, or nitrogen, phosphorus, and potassium), along with some other nutrients, such as iron, magnesium, sulfur, zinc, or copper.
Be careful about adding too much of a supplement to your soil. If you identify a magnesium deficiency and add too much Epsom salt (magnesium sulfate) to your soil, you can end up with a calcium deficiency instead.
How? Well, magnesium and calcium ions compete for uptake by a plant’s roots (these two nutrients are on the same column in the periodic table of elements, so they behave in a similar way).
This means that having too much magnesium in your soil can prevent your pepper plant from absorbing calcium. This is true even if there is plenty of calcium in the soil!
The take-home message: nutrient balance and nutrient levels are both important for the health of your plants. For more information, check out my article on over fertilizing your plants.
If you think your watering, soil, and environment are on-par, then the next thing to do is to look for pests. Sometimes they will be obvious when you look at your plants, but other times they will be hidden. Here are a few common pests (unfortunately, this is not an exhaustive list by any means!)
Aphids are little bugs (over a dozen could easily fit on your fingernail). They can be green, black, white, brown, or other colors. They suck the juices out of stems and leaves on plants, and excrete a sweet secretion (honeydew).
Even though they are small, enough aphids can cause serious problems for a plant – after all, a plant can only produce so much energy, which the aphids are draining away.
If you notice that a pepper plant is infected with aphids, you can try to wash them away with a hose, or you can spray them with a solution of water and dish soap.
Be careful – aphids can spread from plant to plant, so if only one plant is infected, you might be better off removing and destroying the plant, instead of risking the whole garden!
Don’t put a removed plant from the garden into your compost pile, since aphids (or other pests or diseases) can survive the winter in some cases. Then, they will return to haunt your garden in future years when you apply your compost!
For more information, check out my article on how to get rid of aphids.
Cutworms are actually the larvae of moths. They feed on young, tender plants by wrapping themselves around the stem and chewing through it.
Cutworms will curl up into a “C” shape when disturbed, and often come out at night to feed on your plants.
If you see plants “knocked over” that look like they have been “cut off”, then you probably have cutworms in your garden. Even if they don’t chew through the main stem completely, cutworms can still weaken and kill your pepper plants.
For more information, check out my article on how to get rid of cutworms on plants.
Whiteflies are another pest that can weaken or kill your pepper plants. They almost look like tiny moths, and live on the underside of leaves.
You will find them out during the day, in warmer weather, especially in the southeastern U.S. If you shake the pepper plant, you will probably see whiteflies flying around.
Whiteflies also excrete honeydew, the same sticky sweet substance that aphids leave behind. As with aphids, you can use a hose to wash whiteflies away, or use a solution of soap and water to spray your leaves.
If you cannot find any obvious signs of pests on your plants, then it might be time to consider the possibility of a plant disease. Unfortunately, many plant diseases are not curable.
The best strategy is prevention, and if diseases appear, to remove and destroy any affected plants quickly. Let’s take a brief look at a couple of diseases that affect pepper plants.
Fusarium wilt is a fungal disease that exists in the soil. The fungus enters the plant through the roots and spreads to eventually interfere with the plant’s ability to move water around its tissues.
Eventually, the leaves will wilt and turn yellow. The lower (older) leaves on the plant will be affected first.
Fusarium wilt can survive for years in the soil, so using crop rotation is the key to preventing it from spreading and persisting. If you find some of your plants are infected, remove them from the garden and destroy them. (Do not compost them, since this can spread the disease later on!)
Verticillium wilt is another fungal disease that lives in the soil. It acts in a manner similar to fusarium wilt, causing leaves to wilt and turn yellow.
One way to identify verticillium wilt is to cut off a branch from an affected pepper plant, and look at the cross section. If there are dark rings, then your plant probably has verticillium wilt.
There is no known cure for this disease, so as with fusarium wilt, you should remove and destroy any affected plants.
If the problem is widespread, you can use solar sterilization to try to remove the diseases from your soil. For more information, check out my article on soil sterilization.
By now, you should have a pretty good idea of what is causing your pepper plants to keep dying. The most likely problem is over watering. If not, check soil quality and nutrition, look for pests, and if all else fails, try to diagnose a disease.
I hope this article was helpful. If you have a question, please leave a comment below.