A colony of aphids feeding on a rosebud. Photo by: Floki / Shutterstock.

If you have a garden of any size, you’ve probably dealt with aphids at some point in time. Also known as greenflies or plant lice, they are most commonly light green or black, but can also be white, brown, gray, or yellow. The tiny insects, less than ¼-inch long, are usually found on the backs of leaves, bases of stems, on flower buds and fruits, and sometimes roots, depending on the species.

There are many ways to keep aphids in check and avoid using dangerous chemicals in your garden. Aphids have several natural predators, including other insects, insect larvae, and birds. Additionally, they move rather slowly, making them easy to remove by hand or target with sprays. Due to the rate at which aphids multiply, it may take a combination of methods as well as repeated efforts to completely knock out an infestation. Be persistent and patient, as some of the methods take time to see results.

Here are a few methods to try:

Lady beetle larva. Photo by: Geoffrey Budesa / Shutterstock.

NATURAL PREDATORS

Lady beetles:

Lady beetles don’t eat nearly as many aphids as adults as they do in their larval stage, which is why many people are disappointed with the lack of control they see after releasing purchased live ladybugs into their garden. However, there are ways to get better results: Lightly mist plants right before releasing to encourage them to stop for a drink as they are probably dehydrated; and release them in cooler times of the day, early morning or evening. Repeat applications are needed, as most will fly away within a few days.

There also needs to be a large enough aphid population to support them and keep them fed long enough to mate and lay eggs — that’s where the best control will be gained because it’s the larvae that consume the most aphids. Lady beetle larvae don’t look at all like the adults we are all familiar with, so identification is important (see photo). Live ladybugs can be purchased online or at your local nursery.

Green lacewings:

As with ladybugs, green lacewing larvae do the work of controlling aphids. Green lacewing eggs can also be purchased online and occasionally at a local nursery.

Green lacewing larva. Photos by: Tomasz Klejdysz / Shutterstock.

Birds:

Provide houses for bug-eating birds, like wrens and chickadees, to live in and they’ll repay you by helping keep the insect population under control. Grow small trees and shrubs where they can take cover and build their own nests.

PLANT SELECTION

Use plants to your advantage by planting varieties that attract beneficial insects or those that naturally repel aphids. You can also plant some aphid favorites as trap plants to lure aphids away from plants you are trying to protect. Also, keep your garden clean of dead plant material that may be harboring aphid eggs over winter.

  • Attract beneficial insects: Clover, mint, dill, fennel, and yarrow
  • Natural aphid repellents: Catnip, garlic, chives, onion, and allium
  • Aphid trap plants: Zinnias, dahlias, cosmos, asters, mustard and nasturtium

PHYSICAL REMOVAL

Water:

Spray aphids off of plants with a strong stream of water from a garden hose. This method is most effective early on in the season before the infestation has fully taken hold. It may not be a good choice for younger plants or more delicate foliage, but works on more well-established plants where you can use higher water pressure.

Remove by hand:

Put on some garden gloves and knock them off of stems, leaves, flower buds, or wherever you see them, and into a bucket of soapy water to kill them. You can also cut or prune off the affected areas and drop them into the bucket.

NATURAL AND ORGANIC BUG SPRAYS

Soap and water:

Make a homemade aphid spray by mixing a few tablespoons of soap in a small bucket of water and apply with a spray bottle directly on aphids and the affected portions of the plant. Use a pure liquid soap, such as castile, and avoid detergents or products with degreasers or moisturizers. The soap dissolves the protective outer layer of aphids and other soft-bodied insects, eventually killing them. Be sure to soak the undersides of leaves where eggs and larvae like to hide. It doesn’t harm birds or hard-bodied beneficial insects like lacewings, ladybugs or pollinating bees. You can also purchase ready-to-use insecticidal soaps online or at a local nursery.

Neem oil:

The organic compounds in neem oil act as a repellent for aphids, as well as many other insects, including mealy bugs, cabbage worms, beetles, leafminers, ants and various types of caterpillars. Apply similarly as the soap and water method by diluting neem oil in water and spraying, or use a ready-to-use neem oil spray. Neem oil is also good for controlling different types of fungus. However, it may also repel beneficial insects, so use caution when and where they are present.

Essential oils:

Create your own spray mixture with essential oils. Use 4 to 5 drops of each: peppermint, clove, rosemary and thyme, and mix with water in a small spray bottle. Spray on affected plants to target adult aphids, as well as aphid larvae and eggs.

APHIDS 101

An infestation of black aphids. Photo by: gcpics / Shutterstock.

Aphids feed on soft stems, branches, buds and fruit, preferring tender new growth over tougher established foliage. They pierce the stems and suck the nutrient-rich sap from the plant, leaving behind curled or yellowed leaves, deformed flowers, or damaged fruit. Most aphids feed on a wide variety of plants, although some species are specific to certain types of plants.

Aphids don’t like to dine alone, and can usually be found feeding in large groups. Depending on the level of infestation, they can cause serious injury to individual plants or even entire crops. Aphids produce multiple generations in one year and infestations can quickly get out of hand. Treating them early, before they have a chance to reproduce, can make a huge difference in gaining aphid control. Aphids frequently carry viruses and can spread them from one plant to another, often proving fatal to crops like citrus, potatoes and grains.

Aphids secrete a sticky substance called honeydew that attracts ants, so following a trail of ants into a plant can often lead to a discovery of an aphid infestation. Ants are known to protect aphids from natural predators and even herd them into tight colonies so they can harvest the honeydew easier. Honeydew also creates a favorable environment for sooty mold to grow and spread.

Most species of aphids overwinter as eggs and hatch in the spring; however, in warmer climates, they can be an almost year-round problem.

ROOT APHIDS

Root aphids. Photo by: Floki / Shutterstock.

The signs of damage from root aphids are similar, with curled or yellowed leaves and a failure to thrive. Root aphids cause infected plants to be susceptible to root rot, mildew, and other diseases, but many of the above-ground treatments aren’t effective. Root aphids are also common on indoor-grown plants and herbs.

Here are a few suggestions on dealing specifically with root aphids:

Natural predators:

For outdoor plants, predators such as birds feed on aphid eggs, parasitic wasps also attack the eggs, and ladybugs eat aphids they find on top of the soil.

Beneficial nematodes:

Introduce beneficial nematodes into the soil and they will protect against a number of soil-borne pests including root aphids, without harming beneficials like earthworms. Nematodes can be used on indoor or outdoor plants.

Neem oil:

While it won’t kill the root aphids, it can help keep an infestation from spreading.

Avoid spreading infestations:

Be especially careful when relocating or disposing infected plants to not drop soil. This can lead to spreading the infestation to other pots or nearby plants, or tracking soil on the soles of shoes to other locations.

RELATED:
Getting Rid of Japanese Beetles
How to Get Rid of Grub Worms

Free Weekly NewsletterSign up for weekly gardening inspiration and design tips

Join thousands of readers, from avid to casual gardeners, for plant information, gardening solutions, and design inspiration to make the most of your outdoor spaces.

* Required Fields
We will never sell or distribute your email to any other parties or organizations.

More about the newsletter

Follow Us Garden Design Magazine Facebook Garden Design Magazine Twitter Garden Design Magazine Google Plus Garden Design Magazine Pinterest Garden Design Magazine Instagram Garden Design Magazine Youtube

Shop Garden Products

From tools to furniture, these garden products are sure to delight

Discover unique garden products curated by the Garden Design editors, plus items you can use to solve problems in your garden right now, and best sellers from around the web.

Shop Garden Design!