Common Issues When Growing Pepper Plants

Hornworm Caterpillar on Pepper Plant
Hornworm caterpillar on pepper plant

Once planted, pepper plants are usually good to go. Keep them sunny and watered and they'll typically be vibrant, healthy plants. That said – like anything else – sometimes things go wrong. Here are some of the more common issues we've run into when growing pepper plants and what can be done.

Under Watering

Symptom: Green, Droopy Leaves

Commonly seen on hot, sunny days. The plant needs more water. Pepper plants love full sun, but they can get large and do need a lot of water. Watering early morning and in the evening after sun has lowered are the best times. Avoid overhead watering when the sun is strong. If the plant is very dehydrated during mid-day, use a watering can to get water directly to the soil near the plant. Even a significantly dehydrated plant will make a quick recovery with water and the lowering of the sun.

If droopy leaves are common mid-day, either increase watering amount or frequency. If in a pot, transplanting into a larger pot, adding more soil to the existing pot, or moving the pot to a slightly shadier location can help. Common plant dehydration will likely result in reduced growth and yield.

Over Watering

Symptom: Yellow, Droopy Leaves

Yellow, droopy leaves are a classic sign of over-watering – usually combined with insufficient drainage. Typically, we'll see this with potted plants that have no, or insufficient, drainage holes combined with a few days of heavy rain. Step one is to remedy any drainage issue. Then, discontinue watering and let the soil dry out. The plant may lose a few leaves, but if addressed early, it should make a full recovery.

Sun Scalding

Symptom: White, Wilty Leaves
Sun Scalded Pepper Seedlings
Newly transplanted pepper starts can suffer from sun scalding; especially the smaller ones

Pepper plants do love sun, though, they do need time to adjust when being moved outside. While this shouldn't be an issue with pepper seeds sown directly outside, pepper seedlings started inside need a transition period called hardening to gradually introduce the outside conditions of direct sunlight, changing temperatures and wind.

Pepper plants abruptly transitioned to full sun are likely to experience droopiness. Left unchecked, this can progress to sun scalding – a condition that stunts growth, and can possibly kill a young plant.

Plants showing signs of sun-wilt or scalding, should be shaded until they recover – allowing exposure to morning sun, while offering protection from the stronger afternoon sun. Also, extra attention should be paid to make sure the plant receives enough water while it recovers.

Similarly, overwintered pepper plants should be reintroduced gradually to direct sunlight as well. Though, sun scalding presents less danger to these plants as lost leaves are usually regrown in a week or two as long as the plant remains properly watered.

Calcium Deficiency

Symptom: Green, Wrinkly Leaves

This is likely due to the plant having a calcium deficiency. Work a generous amount of bone meal into the soil, then water. Normally, you'll notice an improvement within a week or two.


Symptom: Curling of Newly Grown Leaves or Brownish, Dry and Dying Leaves
Aphids on Winterized Pepper Plant
Aphids on overwintered pepper plant

Usually, this symptom is the result of a significant aphid infestation. Aphids suck fluid from plant stems and leaves. Aphids on outdoor pepper plants are usually kept in check by their predators, and we've yet to experience serious aphid issues with outdoor pepper plants.

On the other hand, aphids can do significant damage to overwintered pepper plants. Household temperatures and a relative lack of predators inside, make ideal conditions for an aphid infestation to take hold. Aphids can also transmit diseases, such as the Mosaic Virus, which render a pepper plant mostly useless and a threat to nearby plants.

We've seen aphid issues most on overwintered plants that were stressed or pruned aggressively and rarely on indoor seedlings or pepper starts, unless under-watered. Based on this and feedback from other growers, we're led to believe that healthy pepper plants are much less prone to aphid issues.

A couple of days before moving potted pepper plants inside, it's a good idea to spray both sides of all leaves, stems, and the soil surface with insecticidal soap (see below). Once inside, quickly move any plants with aphids away from other pepper plants – ideally outside or in the garage, weather permitting – to prevent their spread. Use a water jet spray to dislodge as many of the pests as possible. Allow the plant to dry and reapply insecticidal soap. Inspect in a few days to ensure it's aphid-free before returning.

Insecticidal Soap Ingredients

Homemade Insecticidal Soap

Insecticidal soap can be purchased online or at most garden supply stores. Or, you can easily make your own for a fraction of the price.

  • To make the concentrate, mix one tablespoon of Ivory® Clean body wash with one cup of vegetable oil and shake thoroughly.
  • Mix two teaspoons of the concentrate with one cup of water into a spray bottle. Seal spray bottle and shake.
  • Spray solution on both top and bottom sides of leaves as well as surrounding soil.
  • Wait at least 24 hours before picking peppers from sprayed plants. Always wash peppers thoroughly after picking.

We've Also Tried...
Aphidius Colemani Captured on Sticky Trap
One of many Aphidius colemani sticky trap casualties

We've also tried the yellow sticky insect traps to target aphids. In our use, we've found the traps to be more effective at trapping Aphidius colemani and Aphidius ervi – tiny parasitic wasps that kill aphids (harmless to humans) – than the targeted adult aphid flies.

Apparently, as the aphids are (somehow) hitching a ride into our dwelling, their hunters aren't far behind. As such, we wonder if these traps are counterproductive. We'll be trying them again in the near future to further evaluate.

Mosaic Virus

Symptom: Yellow Spotted, Firm, Wrinkly Leaves

Mosaic, or Cucumber Mosaic, is a virus transmitted by aphids, cucumber beetles and other tiny insects that suck sap from plants. Aphids are usually most active during temperatures of 70-85°F. Mosaic usually results in stunted growth as well as less and poor quality fruit. Unfortunately, there is no cure for this disease. Furthermore, this disease can be transmitted via the above mentioned insects to nearby plants. As such, affected plants should be removed, then burned or thrown away. While we hate the thought of giving up on one of our plants, after pulling we see the infected plant’s tiny, vastly undersized root system and know it didn't have any hope.

It’s believed this virus can live within soil for up to a year. As such, removed plants should not be composted and the affected soil should be not be used for another pepper or tomato plant for a year. Also, keep soil free from weeds during that time as weeds can give refuge to the virus. Consider adding affected soil to a garden bed or landscaping area with other types of plants.

We've yet to see this virus on plants that were raised and kept outdoors. For us, it's most common with overwintered plants – where aphids can be an issue. With a little preparation and diligence, we've been able to mitigate aphid issues. Our Keeping Pepper Plants for Another Year Guide has more information on what we do.

Garden Slugs

Symptom: Leaves With Numerous Eraser-Sized Holes in Them
Slug Trap Near Affected Plant
Slug trap near affected pepper plant

Leaves with many holes seemingly punched in them are a telltale sign that garden slugs are feeding on your pepper plants. In most cases, leaf damage is minor and not worth worry. Though, with damp and slightly shady conditions, garden slugs can be a nuisance. If the leaf damage gets significant (leaves start looking like Swiss cheese), it's time to take action. Left unchecked, slugs can kill a small plant.

Slugs thrive in damp and shady conditions. With part-shade or a bout of rainy/cloudy weather, garden slugs can establish themselves. If in pots, moving plants to a sunnier location will help.

If you're unable to move the plants, we've found filling a small tray (a few inches across and an inch or two deep) with an inch or so of beer to be an effective solution. The slugs are attracted to the beer and end up drowning (don't know when to say when?). This tends to work quickly as we've seen trapped slugs within a few hours of setting a trap. The beer should be refreshed every couple of days. We'll typically refill a time or two until the traps are no longer catching slugs. We've seen these traps catch up to eight slugs on a medium-sized potted pepper plant.

Hornworm Caterpillar

Symptom: Leaves Eaten from Outside Edge Toward Leaf Stem

If the plants leaves are being mostly, or completely eaten – from the edge of the leaf inward – the likely culprit is the Hornworm caterpillar (pictured at the top of this page). These caterpillars grow large and can eat quite a bit. They do turn into a pretty cool moth (in our opinion), so if necessary, we'll relocate it/them to a grape vine which is also a food source for this caterpillar. Though, some do suggest more drastic measures (what happens in your garden stays in your garden).


Symptom: Plants Being Dug Up

Small critters love to dig in fresh soil. For us, the chipmunks are known offenders (and possibly squirrels). They tend to dig in the same spots over and over again, getting more aggressive with their digging over time – sometimes uprooting our smaller plants. We refill their holes and re-seat plants, though at times we find their persistence is greater than ours. We recently started an experiment of putting high-octane pepper powder in the areas they're digging. So far, it appears to be working!


Symptom: Small Peppers Disappearing or Tips of Peppers Getting Eaten
Thai Pepper Eaten by Pest
Tip of Thai pepper eaten by unknown pest – birds or mice?

Occasionally, we'll see a rash of ripened pepper tips being eaten and the small berry-like peppers being prone to complete removal. With the affected varieties, it also appears that the more ripe the pepper, the more likely it is to have damage. Many times, this will occur all over the plant, even in the upper portions.

From an evolutionary perspective, chile peppers were "designed" to be eaten by birds, as the pungent capsaicinoids they contain tend to deter mammals from ingesting them (with a notable exception or two). So, it's quite natural for birds to desire the smaller, more manageable peppers.

Hanging shiny spinners, CDs or aluminum tins to create movement and noise with the wind can help to scatter birds. Some gardeners claim success with plastic predators, like owls and snakes. With either of these, they should be moved every one or two weeks, so the birds don't get used to their presence. If they're in pots, bringing the plants inside, or onto a patio, once the fruit starts to ripen can also help. We've had good results with simply harvesting the susceptible varieties as soon as they ripen, or slightly before.

Mice or Their Larger Cousins

Symptom: Larger Peppers Disappearing or Tips of Peppers Getting Eaten

And, a not so common issue we recently experienced…

In 2019, we had few jalapeno and guajillo plants that were mysteriously losing every pepper as they ripened. When small peppers disappear, it's usually due to birds. Jalapenos on the other hand, seem a bit too big for our local birds. Additionally, the whole peppers were disappearing without a trace – with no fragments being left behind.

Baffled, we set up a motion-detecting camera and found our culprit – a mouse caught red-handed raiding one of our jalapeno plants just after midnight. Later that same morning, it returned to feed on a nearby ornamental pepper.

The capsaicinoids in spicy peppers are supposed to deter mammals from eating them. Ever since we've been growing peppers, this had been true. Though, it's now apparent that occasionally these critters can acquire a taste for them. Interestingly, in our case, anything hotter than those varieties were spared – except for the tips of our nearby Thai peppers, Since the tips of peppers usually contain less pith/heat than the upper portion, we're now wondering if it was the birds in 2018 taking our Thai pepper tips, or this visitor building up its tolerance.

Picking the peppers before they ripen, trapping the vermin, or relocating the plants are the only remedies we initially explored – with early harvesting and relocation working the best. Another option we recently learned of (and will try next time), is non-toxic deer spray – though if effective, would require thoroughly washing the fruit after harvesting to remove the foul taste. A similar thought would be liquefying a super hot variety into a spray.

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