Pepper plants are prone to all kinds of ailments, diseases, and infestations. Being able to recognize symptoms and signs of distress early can make all the difference between a healthy, thriving pepper plant and an unhealthy or dead one.
Common pepper plant diseases include blight, verticillium wilt, blossom-end rot, root-knot, and root rot, and symptoms include yellowing, curling, or scorched leaves; black spots on stems; or holes in leaves. Proper amounts of water, humidity, and nutrients can help prevent these ailments.
If you don’t know how to diagnose pepper plant diseases properly, you run the risk of your plants dying from them. This article covers most of the common problems that pepper growers face and what you can do to prevent them.
Commonly Observed Ailments in Pepper Plants and How to Treat Them
This is, perhaps, the single most common ailment many pepper growers have to deal with. Although yellowing leaves are a common symptom of more serious issues, most of the time, it probably won’t be that big of a deal as it is also part of the plant-aging process.
When yellowing is not due to aging, that generally means something is wrong. It may be a matter of over-watering or a lack of nutrients. Any part of the leaf may begin to yellow—even just the veins—and eventually fall off.
How to Fix Yellowing Leaves
If you notice yellowing leaves on your pepper plant, you might have to adjust the amount of water you are providing it, or the amount and/or type of fertilizer.
When it comes to watering your pepper plants, make sure to only give your plant water when needed, and try not to over water it. It’s okay to let the first inch or so of soil dry between watering.
If the leaves turn yellow, but the veins remain green, that might be a sign of chlorosis, which means a magnesium deficiency might be to blame. A lack of calcium could also cause leaves to turn yellow. If yellowing starts at the plant’s base and moves upwards, your peppers need nitrogen.
Just like yellowing leaves, curling leaves may be a sign of something worse, but there is likely a smaller issue at hand. Leaves may curl or otherwise appear distorted, or might look stunted. When this happens it may be a sign of:
- A calcium deficiency
- Too much light
- Plant edema (identified as white, crystalized bumps on the underside of leaves)
How to Fix Curling Leaves
Provide adequate calcium to help plants form strong cell walls. Treat the soil before planting or use a fertilizer with calcium.
If growing your pepper plant indoors with the assistance of grow lights, make sure the lights are not too close to your plants. Keep LED lights around 12 to 15 inches (30.5 to 38.1 cms) away from plant leaves, so that your plant is not overhwating. If plants are outdoors, ensure that they aren’t overly exposed to heavy sunlight, and provide additional shade if necessary.
Don’t over-water your pepper plants! We can’t stress this enough.
If plants show signs of plant edema, poor air circulation may be the cause. Increase airflow by spacing peppers further apart in an outdoor garden or with a fan indoors.
Scorched, dry, brown, and crumbly leaves may be due to any number of reasons. Like the other leaf ailments listed above, these could be signs of nutrient imbalances, environmental stress, pest infestation, or disease.
When leaves turn brown and crumble, this is generally a sign of insufficient watering. If this is the case, you may also notice leaves dropping and your plant might also start to droop. Scorched leaves may also be the result of sunburn, frost damage, or other temperature-related injuries. Typically, such damage results in the entire plant becoming discolored and wilted.
How to Fix Scorched Leaves
Pepper plants should be watered regularly and deeply at the base, when their soil feels dry.
Additionally, keep plants in a location in your garden where it will get proper sunlight, shade, and other environmental requirements for healthy growth.
If plants that are generally well-cared for have brown, scorched leaves, it may be a sign that something else is wrong. You may have an infestation of whiteflies, for example, as these insects suck juices from the plant, which leads to yellowing and then browning of the leaves.
Black Spots on the Plant
Black spots on your pepper plant may not always be cause for alarm. In some cases, you may notice a darkening on plant stems in or around the joints. This is actually quite common and natural, more so in Bell peppers and Jalapeños, but it may occur in any type of pepper plant.
If you see this happen on your plants, don’t worry, as the fruit is seemingly unaffected and considered safe to eat. Although the exact cause of why this happens is not known, it seems as though it could be a reaction to stress that causes an excess of anthocyanin pigments to buildup. In any case, such spots are not a sign of disease but rather a natural response to some kind of stimuli.
The fruits can be affected by this as well, causing their skin to look black—technically, a deep purple—in appearance. This may change all or some of the skin color, but the fruit remains safe to eat.
How to Fix Black Spots on a Pepper Plant
With the pigmentation issues above, there is no pressing danger to the plant that needs to be addressed. These are naturally occurring abnormalities that simply affect the visual aesthetic. However, if spots on the stem are occurring near the plant’s base, and spots on the leaves are present as well, then this means your plant has a disease, such as blight. You can read more about blight in the section below.
Leaves Have Holes in Them
If you find holes in leaves that have mild or no discoloration, this is often a sign of some kind of pest infestation. There are many insects that love to feast upon pepper plants, so this is most likely the issue.
However, if your plant has developed brown or black dead spots on its leaves, this is known as a bacterial spot. It is a particularly destructive disease as it will eat away at your plant’s leaves, cause early leaf drop, and create spotting on stems. Warm weather, high humidity, and heavy dew on leaves all increase the development of this disease, and it is spread from plant to plant via splashing water.
Early symptoms first appear as water-soaked areas on the undersides of the leaves. Over time, these areas enlarge and turn dark brown or black. The tops of the leaves will then display beige spots with brown borders.
How to Fix Leaves With Holes in it
If pest infestation is the issue, use organic pesticides or other appropriate measures to alleviate the issue. You can also take steps in pest-prevention through soil preparation and such before planting.
Bacterial spot, on the other hand, is tough to control once a plant is infected, and you will likely have to get rid of the plant so as to avoid the disease spreading to other plants in your garden. You can prevent or slow the development of this bacteria, however, by using copper-based sprays and protecting the plant from overly humid environments in general.
Common Bacterial, Viral, and Fungal Infections that Affect Peppers and How to Treat Them
There are different types of blight, generally called early blight or late blight. Most symptoms of each are the same, but certain types of blight are prone to different parts of the world at various times in the growing season. Pepper plants usually have lower leaves affected because rainfall causes soil to splash onto the foliage, thereby spreading the disease.
One particular strain of blight, known as phytophthora blight, is a soil-borne pathogen. This specific type of blight can lead to damping-off and root rot (see below). Another unique type, southern blight, is a fungal infection that can be identified by mycelia mats growing on the plant stem and in the soil.
How to Identify Blight
- Leaves have large, brown spots and are wilting
- The stem is brown or black at the plant’s base
- You see signs of root rot (more info on that below).
- If low-hanging fruit that has contact with the soil begins to rot (evidence of a pathogen in the soil).
How to Fix Blight
Blight is found commonly in gardens and fields because the rain will splash soil all about and leave plants soaking in standing water at times, which is how blight mold spores multiply. They will then spread out, infecting all the plants the water reaches.
With this in mind, do not over-water your plants. If your pepper plants get dry, provide multiple smaller watering sessions throughout the day to avoid drowning them.
A good way to lessen the chance of this is to plant peppers in raised beds or pots to allow for good drainage.
Encourage further protection in each plant by mounding up the soil around them to prevent standing-water at their base. This is a good trick for in-ground plants, particularly as they don’t have a raised bed or other container’s drainage assistance.
Additionally, you can use some type of ground covering—tarps, straw, mulch, etc. This will keep soil from splashing up onto your pepper plants when it rains. Plus, such coverings can assist in moisture retention as well as subduing weeds.
This infection is caused by fungi and can affect many plants, including all nightshade family members that may grow in your garden. Some symptoms of verticillium wilt actually mimic the natural aging process, so it’s possible to overlook this infection. The real give away is that symptoms are typically only seen on one side of the plant at first.
If allowed to grow, this will eventually cause your pepper plants to collapse and die. So, if you see signs of this disease, take action immediately.
How to Identify Verticillium Wilt
- Leaves will turn yellow, wilt, and die, often on one side of the pepper plant
- Vascular discoloration is present (this is a brown streaking in the vascular tissue, which is identified by peeling away the outer layers of infected parts of the plant).
- Plants have fully collapsed
How to Fix Verticillium Wilting
If your peppers are infected with Verticillium, you will not be able to cure them, and they will eventually die. Unfortunately, they will have to be removed and destroyed. Non-vegetative plants can have their lives extended with proper watering and fertilization, but they will inevitably succumb to the disease as well.
Make sure you are providing all the nutrients your peppers need to avoid such a fate. Fertilization should be appropriately supplementing the soil, and watering should stay consistently sufficient.
Remove affected plants away from others to prevent spreading. Insects can also spread this infection, so pest control is important.
Blossom End Rot
Blossom end rot is typically caused by a calcium deficiency, although hot temperatures and irregular watering will produce the same symptoms. This isn’t an actual rot, rather a condition that affects the fruit’s skin from forming properly. This in turn will lead to rotting and mold, and thus inedible fruit (the portions that are affected, anyway).
How to Identify Blossom End Rot
- Soft, dark spots on the bottom of pepper pods
- Shriveled, dead skin
- Mold inside peppers
How to Fix Blossom End Rot
Always use nutrient-rich soil and fertilizers to provide sufficient nutrients for your pepper plants. Products like cal-mag foliar spray or bone meal can be used prior to planting to enhance your soil’s calcium levels. Also, if your soil’s pH level is below 6.0, adding limestone can help reduce the chance of blossom end rot from occurring.
Be sure to maintain even moisture in the soils—using mulch will help. Additionally, avoid subjecting plants to temperatures above 90 degrees Fahrenheit (32 degrees Celsius).
The name root-knot refers to the “knotty” appearance that roots get when infected by nematodes, which are microscopic, parasitic roundworms that pierce a plant’s roots and lay eggs inside them. Root-knot nematodes, in particular, cause major crop loss in many areas of the country every year.
How to Identify Root-Knot
- Plant growth is generally stunted
- Nutrient deficiencies are noticed in leaves (typically, yellowing occurs)
- Roots have galls or swellings
How to Fix Root-Knot
There are a few steps you can take before planting peppers to prevent root-knot. Once nematodes infest a plant’s roots, there are no good treatments available, so prevention is the best ure. For starters, you can choose nematode-resistant varieties of peppers to plant in your garden, such as Carolina Wonder or Charleston Belle. Then there are some best practices in general that you should adhere to, such as:
- Exercise good crop rotation
- Remove old plant roots when clearing garden beds
- Till soil two to three times each fall
- Plant overwintering grass cover crops
- Add organic material to the soil regularly
Other solutions include using a nematicide to help subdue the populations present in the soil and planting marigolds as companion plants, since they are toxic to root-knot nematodes.
Damping-Off or Root Rot
These two terms are used interchangeably to refer to the same thing, but there is a slight distinction. Root rot is a fatal disease caused by various soil-borne pathogens and it typically infects the plant starting at the roots, which inevitably leads to damping-off (among other things).
The term damping-off refers to the sudden death of seedlings from root rot infections. However, on rare occasions, damping-off may be caused by something else.
Root rot usually invades at the small, feeder roots of the pepper plant. It attacks quietly, and often, plants will show no symptoms until the infection is serious. By then, it will be too late to save the plant. Other times, root rot will attack stem, leaves, or fruit as well. This leads to rotten, brown spots that will separate easily from the rest of the plant.
Damping-off can kill or weaken seedlings both pre- and post-emergence. It occurs more frequently in cool, wet conditions as well as when soil is compacted, and airflow is poor. Eventually, tissues soften and restrict, causing the plant to wilt and fall over.
How to Identify Root Rot
- Yellowing is present throughout the plant
- The plant is wilted or leaning, even when the soil is moist
- Growth is generally stunted
- Fruits are small or otherwise poorly produced
- There are rot and mushy brown spots in stems, leaves, or fruit
How to Fix Root Rot
Prevention is the best treatment for root rot. Soil conditions should be properly maintained, over-watering should be avoided, and good airflow is critical as well.
Death is usually inevitable once plants begin showing above-ground effects of root rot, and sadly you will be unable to save the plant. Only by catching this disease before the plant begins to wilt will it have a chance for survival. If you suspect root rot, increase drainage and avoid over-watering.
If your pepper plants have recently been bogged down with water, you will want to inspect their roots for damage. Rotten roots that have become brown and mushy should be removed and thrown away. The plant should be replanted in fresh, sterile, well-drained soil.
To avoid spreading infection, remove root rot infected plants away from healthy ones. Diseased plants should not be placed in compost piles or other areas where they could potentially infect other plants.
Soil that has root rot pathogens can be sterilized by baking it in the oven. Allow the infected soil to reach a temperature of 180 degrees Fahrenheit (82 degrees Celsius) for 20 minutes and then cool completely before planting.
Common Pepper Plant Pests and How to Get Rid of Them
Insects can cause a lot of damage and the list of pests that may infest your pepper plants is a long one. Luckily, there are preventive measures you can take to control this issue. Here are the common pests that may infest your pepper plants:
- Flea beetles
- Corn borers
- Spider mites
How to Identify Pests
- Pests are visible under the leaves, on stems, etc.
- Leaf damage such as holes
- Dark spots on leaves
How to Get Rid of Pepper Plant Pests
Which type of pest you have will best determine which solution is best. Some larger pests are often fewer in number and can easily be removed. Smaller pests, however, tend to come in large swarms that are not easily persuaded to leave.
Directly spraying leaves with water can knock many pests off your plant. It’s not a permanent fix, but it will certainly slow the devastation.
You can use insecticidal soaps and other organic pesticides to control virus vectors. Neem oil is a natural pesticide you can use to kill existing pests and prevent others from coming. This can lead to a reduction in diseases caused by infestations as well. Spray the plants with a solution of 1 tablespoon pure neem oil and castile soap in six cups of water.
Eliminating ornamentals and weeds around your peppers will also help to reduce virus spread. A great, natural way to combat pest infestation is to release natural predators like ladybugs, lacewing flies, and praying mantises.
Furthermore, you can reduce pests with gardening practices such as inter-planting, crop rotation, and by keeping plant foliage dry.
Pepper plants that are not properly cared for can easily fall victim to pests or disease. If your plants show signs of disease, act quickly to save the plant or stop infections from spreading. In general, preventive measures taken prior to planting and proper plant care will reduce the chance of infection and infestation.
Here are Some of my Favorite Gardening Products and Tools
Thank you for reading this article. I hope you found it helpful for growing some new plants in your home or garden. Here are some products I like that I hope you’ll also find helpful. These are affiliate links, and I am compensated for referring traffic. But in all honesty, these are the exact product that I use or recommend to everyone.
Soil: For high-quality soil, I really like Fox Farm Ocean Forest. I do all my growing in containers and this soil has worked great for me. I like how they use nutrient-rich contents like earthworm castings, bat guano, and composted crab and fish.
Fertilizer: Currently I am using a seaweed-based organic fertilizer call Neptunes Harvest. This is a great milder fertilizer option if you want to use something organic. If you want a more powerful fertilizer, I recommend Fox Farm Liquid Nutrient Trio, lots of people have had great growing success with this product.
Pruning Shears: Pruning shears are one of the most useful gardening tools to have because it’s important to prune your plants to keep them healthy. The pruning shears I recommend are the Gonicc 8’’ pruning shears. I like them because they are built sturdy and work both on bigger and smaller plants, so you don’t need to have multiple pruning shears.
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