What are those small green bugs that are on your plants? Most likely, they’re aphids. Here are our best ideas for getting rid of aphids in your garden.
What Are Aphids?
It seems like aphids get into every garden. They have soft bodies and live by sucking liquids from plants that are full of nutrients.
They can make a lot of plants much weaker and kill flowers and fruit. Aphids have a lot of babies quickly, so it’s important to get rid of them before they have babies. In one season, there may be more than one generation.
The good news is that aphids don’t move around quickly and can be controlled by paying close attention.
Adult aphids are less than 1/4 inch long, so they are usually too small to see with the naked eye. Different species can be white, black, brown, grey, yellow, light green, or even pink! Some may have a waxy or fuzzy layer on them.
Aphids have pear-shaped bodies and long antennae. Aphid nymphs look just like adult aphids. Most species have two small tubes sticking out of the back of their bodies. These are called cornicles.
Adults usually don’t have wings, but most species can develop wings when there are too many of them.
Aphids eat a wide variety of plants in general, but some species of aphid may only eat certain plants.
Some examples of aphids are bean aphids, cabbage aphids, potato aphids, green peach aphids, melon aphids, and fuzzy apple aphids.
What Does Aphid Damage Look Like?
Depending on the species, nymphs and adults feed on plant fluids by attacking leaves, stems, buds, flowers, fruit, and/or roots. Most aphids especially like juicy new growth. Some, like the green peach aphid, feed on a wide variety of plants, while others, like the rose apple aphid, only feed on one or a few plants.
- Check for leaves that are misshapen, curled, short, or turning yellow. Check the undersides of leaves for aphids because that’s where they like to hide.
- Aphids have been sucking sap if the leaves or stems are coated with a sticky substance.This “honeydew,” which is a sweet liquid made by insects as waste, may attract other insects, like ants, who eat it. Aphids eat the leaves of trees, and their honeydew can get on cars, outdoor furniture, roads, and other places.
- Honeydew can sometimes help a fungus called sooty mould grow, which turns branches and leaves black.
- Aphids that eat flowers or fruit can change their shape or make them look distorted.
Some species of aphids cause galls on the roots or leaves.
- Aphids can spread viruses to plants and attract ladybugs and other insects that eat them.
How to Get Rid of Aphids
- Spray the plants with a strong stream of water; sometimes a strong blast is all it takes to get rid of aphids. Most of the time, they can’t come back to the same plant.
- Neem oil, soaps that kill insects, and horticultural oils can all kill aphids, but they have to touch the bugs for them to work. Follow the directions on the package for how to use it.
- Aphids can usually be gotten rid of by wiping or spraying the leaves of the plant with a solution of water and a few drops of dish detergent. Apply soapy water every two to three days for the next two weeks.
- In one version of this soap-water mixture, cayenne pepper is added.
1 quart of water, 1 teaspoon of liquid dish soap, and a pinch of cayenne pepper Don’t dilute the spray before using it on plants.
- Do not use DE when plants are in bloom because it can hurt pollinators like bees and butterflies if they touch it.
How to Prevent Aphids
- Spray horticultural oil on fruit and shade trees while they are dormant to kill aphid eggs that have been there all winter.
- Aphids are eaten by ladybugs, lacewings, and parasitic wasps, all of which are good bugs. You can get these insects to come to your garden by giving them access to water and a variety of flowers and plants with leaves. You can buy more of these insects online, which should help keep the number of aphids under control from the start.
- Companion planting can help keep aphids away from your plants in the first place and also lure them away from the plants you want to grow.
- Catnip, for example, repels aphids.
- Mustard and nasturtium are especially attractive to aphids. Put them next to more expensive plants to catch aphids. Most likely, aphids will attack these plants before your tomatoes. (Check your trap plants often to keep aphids from migrating to your most valuable plants.)
- Aphids don’t like the taste of fruit tree sap, so nasturtiums keep them away from broccoli by covering up the taste.
- Garlic and chives keep aphids away from lettuce, peas, and roses when they are planted near them.
Using Alcohol to Control Aphids
Isopropyl alcohol, also called isopropanol or rubbing alcohol, works well and is easy to find, but make sure it doesn’t have any chemicals in it.
Ethanol, or grain alcohol, seems to work best. Most shops sell alcohol that is 70% strong. To make an alcohol solution that kills insects, mix equal parts 70% alcohol and water.
Don’t spray these solutions all over the plant at once. Only spray or wipe the spots that are dirty. It will only kill the aphids it comes in contact with, so you may need to treat your plants more than once.
Warning: Always test a soap or alcohol spray, or a mixture of the two, on a small part of the plant first, and use the spray in the morning or evening, when the sun isn’t as strong. Wait a few days to see if you get any rejections before sending in more applications.
Plants may die if they get too much alcohol or dish soap. Also, some soaps have chemicals that could hurt plants, so choose the one that is the cleanest.