Aphids seem to like every vegetable in the garden, but if you’re a pepper grower, it’s especially distressing when you start noticing the little green buggers clustered all over your leaves and buds.
While a few aphids isn’t something to be worried about, if left unchecked, heavy infestations can severely weaken your pepper plants and negatively impact your pepper yields. Young pepper plants are especially vulnerable.
Aphids are one of the most common pests in the garden, but luckily there are several ways to easily control aphids on your pepper plants.
Signs of Aphids on Pepper Plants
Aphids are difficult to identify with the naked eye, so you may not even know if you actually have aphids or not.
Aphids are small, usually wingless, insects which suck the juices out of your plants. They are commonly light green, which helps them blend in, but can also be white, brown, gray, black, pink, or yellow. They have long antennae and often have two smaller antennae sticking out the back as well.
You can find aphids anywhere on your pepper plants, on the leaves, stems, and even flowers, but they prefer soft, new buds and leaves.
There are a few signs that you may have aphids. In heavier infestations, you will notice leaves curling up and dying, and a sticky sap on younger leaves and branches. Another major sign is seeing ants crawling all over your pepper plants. Sometimes ants will “farm” the aphids, taking that sticky, sweet sap for themselves while protecting aphids from predators. Because ants are not exactly fond of pepper plants, so if you see them, you should look carefully for aphids.
Dealing with a Minor Presence of Aphids on Pepper Plants
Just a few aphids on your pepper plants are often nothing to worry about, but can be a sign of a future large infestation. Fortunately, aphids are one of the easiest pests to control.
Unlike scale insects, aphids can be easily blasted away with a water hose, and this is always my first line of defense against aphids. You would think they would just find their way back to your pepper plants, but aphids are quite dumb and clumsy, and most will get lost or distracted before they can find your pepper plants again.
A more effective strategy is to spray your pepper plants with soapy water (4 teaspoons of liquid dish soap per 1 gallon of water). The soapy solution helps smother the aphids, but you can also use it in combination with spraying down your plants with the garden hose, which will make it harder for the aphids to hold on. Then you can spray your pepper plants one more time with soapy water. Reapply every few days as a preventive measure until you notice no more aphids. Apply the soapy water all over your pepper plants, including under the leaves.
Heavy Aphid Infestations on Pepper Plants
If you have a major infestation of aphids, I recommend starting with spraying down your pepper plants with soapy water first. If that doesn’t work, there are a few other organic options.
Neem oil is a tried-and-true, all-purpose organic insecticide. It’s a natural oil which contains compounds that disrupt insect hormones, which causes insects to lose their appetite and negatively impacts their growth and reproduction. Neem oil won’t instantly kill your aphids, but will gradually reduce their numbers and kill them off.
Most commercially available pure neem oil should be diluted and mixed with soap to help it stick to the leaves and stems of your pepper plants. Always follow the dilution instructions on the label, but a common dilution rate is 1 teaspoon of neem oil and 1/2 teaspoon of dish soap per gallon of water. Some neem oil comes in already diluted sprays. Neem oil especially can burn your leaves if your pepper plants are already stressed, so always test it on a few leaves first and check after a few days to see if your pepper plants tolerate it.
Another option is to use insecticidal soap. This is more readily available so you may be able to find it at your local Walmart or other big box store. There are two kinds of insecticidal soap you can find: with only soap made with potassium salts, and with both soap and pyrethrins.
The potassium salt soap component will behave similar to dish soap, but also help degrade the protective outer skin of the aphids so they dehydrate faster and die. Pyrethrins are organic compounds derived from chrysanthemum flowers which kill a wide variety of insects. It kills fast, but also breaks down very quickly, so you will need to reapply every few days.
If you use insecticidal soap with pyrethrins, either avoid spraying on the flowers or spray in the evenings because pyrethrins can kill pollinators such as bees as well as pests.
Again, with any sprays, like neem oil or insecticidal soap, it’s a good idea to test spray a few leaves or part of your plants first and check back after a few days to see how well your pepper plants tolerate it.
Control Aphids with Natural Predators
One approach to pest management is by allowing nature to do the work for you. Aphids, being plump, soft-bodied, bite-sized insects with bellies full of sap, are basically a delicacy for predatory insects.
Ladybugs are the most common type of predator of aphids, and you can actually buy them at nurseries, garden centers, and also online (including Amazon). Simply release them in your garden and they will do the work for you. Note that ladybugs will only stick around if there are aphids, so if you are using ladybugs to prevent aphids, they’ll just end up flying somewhere else where the food is.
There are tons of other general predators that eat aphids such as lacewings, hover flies, and various wasps, including parasitic wasps which lay their eggs inside the aphids for their larvae to eat from the inside.
Parasitic wasps don’t actually eat the aphids themselves, so you can attract them by having plenty of flowers in your garden. Marigolds and various flowering herbs like thyme, rosemary, dill, lavender, and fennel can help attract these helpful wasps as well as other beneficial pollinators.