Aphids: How to Organically Control Aphids in The Garden

Aphids are likely one of the garden pests all gardeners have had to deal with more than once. Flowers, fruit, vegetables, herbs – aphids are not picky; they will destroy everything. And once you see a few, it only takes days for those “few” to turn into a full-on infestation. And aphids may seem small and unobtrusive – you can squish those little pests fairly easily under a fingernail – but they manage to do a LOT of damage. But before you run and spray chemicals, many ways exist to organically control aphids in your gardens.

In this post, we’ll take you through everything you never thought you needed to know about aphids, from their growth cycle to how you can upend infestations before they even begin, and how to use preventative measures so you don’t get another infestation next year. It’s a lot of ugly bug photos (UGH I know, me too) but it’s one of those grin-and-bear-it type posts.

Identification of Aphids

Aphids are small, soft-bodied insects commonly found in gardens and ornamental plants like roses, trees, and shrubs. They are usually less than 1/8 inch long and have pear-shaped bodies. Aphids can be in many colors, including green, brown, black, yellow, or red. Some species have wings, while others do not.

Related: Spider mites are similar in appearance to aphids, and cause similar damage to plants. Check out our article on identifying and eliminating spider mites to learn more!

Physical characteristics

Aphids have a unique physical characteristic that sets them apart from other insects: they have two small, tube-like projections called cornicles that protrude from their hind end. These structures secrete a defensive fluid that can repel predators and other insects.

Common types of aphids found in gardens

There are over 4,000 species of aphids, and I think they had a family reunion here in Nova Scotia last year. Some of the most common species of aphids include: 

1. Green peach aphid (Myzus persicae): One of the most common aphids found on various plants. They are usually green in color and can cause significant damage to crops.
2. Soybean aphid (Aphis glycines): As the name suggests, these aphids feed on soybean plants and can cause stunted growth and reduced yield. They are usually pale yellow in color.
3. Woolly apple aphid (Eriosoma lanigerum): These aphids are commonly found on apple trees and can cause significant damage to the fruit. They are covered in a white, waxy substance that gives them a woolly appearance.
4. Black bean aphid (Aphis fabae): These aphids are commonly found on bean plants and can cause significant damage to the crop. They are usually black in color.
5. Rose aphid (Macrosiphum rosae): These aphids are commonly found on rose bushes and can cause the leaves to curl and become distorted. They are usually green in color.
6. Melon aphid (Aphis gossypii): These aphids feed on various plants, including melons, cucumbers, and peppers. They can cause stunted growth and reduced yield.

Aphid Life Cycle

Aphids undergo a complicated life cycle that encompasses both sexual and asexual reproduction. While the specifics of this cycle may differ according to the species and environmental factors, here is a brief summary:

1. Egg stage: In the fall, adult female aphids lay eggs that will overwinter on plants or in the soil. In some species, the eggs will hatch in the spring, giving rise to a new generation of aphids.
2. Asexual reproduction: Some species of aphids can produce multiple generations of offspring through asexual reproduction. Female aphids can give birth to live young (nymphs) without needing a mate. And the larvae mature quickly and can begin reproducing within a week. This is how aphid populations, if left unchecked, can explode in a very short period of time.
3. Sexual reproduction: In the fall, some species of aphids will produce males and females, which will mate and lay eggs that will overwinter.

Aphids can have a significant impact on a garden. These tiny insects feed on plant sap, leading to leaf wilting, curling, and yellowing. Their excretion of honeydew can attract ants and other insects while promoting the growth of sooty mold that can cause further harm to plants. Aphids are also carriers of plant viruses that can cause significant damage to plants.

If left untreated, aphid populations can increase and cause significant damage to a garden. However, you can use many organic management techniques to control aphids, such as attracting natural predators, companion planting, homemade aphid sprays, manual removal, and soil maintenance.

Common Signs of Aphid Infestation

Aphids are often easy to spot because they cluster on the leaves and stems of plants. They may also leave a sticky residue called honeydew on the host plant, attracting ants and other insects. Some other signs of an aphid infestation include:

Stunted plant growth: Aphids can weaken plants by sucking the sap out of their leaves and stems, which can cause the plant to become stunted or deformed.

Yellowing or wilting leaves: As aphids feed on the leaves of a plant, they can cause the leaves to turn yellow or wilt.

Curling or distorted leaves: Aphids can cause leaves to become twisted or distorted, making them look unappealing and reducing their ability to photosynthesize.

Identifying aphids is crucial to managing them effectively in your garden. Knowing the physical characteristics of aphids, the common types found in gardens, and the signs of aphid infestation can help you take the necessary steps to protect your plants from these pesky insects.

The Importance of Organic Pest Management

Organic management of aphids in the garden is vital for several reasons. It is better for the environment and safer for you and your family.

Benefits of Organic Management

Healthier plants: Organic management practices can help promote healthier plants by encouraging natural growth and reducing the impact of harmful pests and diseases.

Better for the environment: Organic management practices are more sustainable and have less environmental impact than chemical pesticides. They can help reduce pollution, conserve water, and protect wildlife.

Safer for humans and animals: Organic management practices do not use harmful chemicals, which can be toxic to humans and animals. 

Chemical Pesticides Are Harming Us, Our Animals, and Our Environment

We must stop using harsh chemical pesticides and fertilizers in our backyard gardens. There are so many reasons, but here are the top three that should be enough to convince anyone to stop:

Harmful to humans and animals: Chemical pesticides can harm humans and animals if not used properly. They can cause skin irritation, respiratory problems, and other health issues.

Damage to the environment: Chemical pesticides can also hurt the environment. They can pollute the soil, water, and air and harm beneficial insects and wildlife.

A build-up of resistance: Overuse of chemical pesticides can lead to pest resistance, making them more challenging to control in the future.

Organically Control Aphids With These Common Methods

Aphids can be controlled organically using techniques that don’t rely on chemical pesticides. Here are some organic management techniques you can use to control aphids in your garden:

Natural Aphid Predators

A helpful method for controlling aphids is by promoting the presence of natural predators in your garden.

There are many natural predators of aphids that help to keep their populations in check. Some of the most common predators of aphids include:

1. Ladybugs: Ladybugs are perhaps the most well-known predator of aphids. They feed on both eggs and adult aphids and can consume large numbers of them in a short amount of time.
2. Lacewings: Lacewings are another common predator of aphids. They feed on eggs, larvae, and adult aphids and can consume large numbers of them each day.
3. Hoverflies: Hoverflies are another insect group that feeds on aphids. They lay their eggs near aphid colonies, and the larvae feed on the aphids.
4. Parasitic wasps: Many species of parasitic wasps prey on aphids. They lay their eggs inside the aphids, and the developing larvae then feed on the aphids from the inside.
5. Birds: Many species of birds, such as chickadees and titmice, feed on aphids, particularly in the spring when the insects are most active.
6. Spiders: Some species of spiders, such as crab spiders and jumping spiders, will feed on the aphids they capture in their webs.

These are just a few examples of the many natural predators of aphids. By keeping aphid populations in check, these predators play an important role in maintaining the health of plants and ecosystems.

Companion Planting

Companion planting involves planting certain plants together that can help deter pests from your garden. Here are some companion plants that may help control aphids:

1. Chives
2. Garlic
3. Basil
4. Petunias
5. Mint
6. Rosemary
7. Dill
8. Catnip
9. Onion

Homemade Aphid Sprays

Several natural ingredients can be used to make homemade aphid control sprays. These sprays are easy to make and can be applied directly to plants to control aphids. Here are a few recipes:

1. Neem oil spray: Mix one tablespoon of neem oil with 1 quart of water and a few drops of dish soap. Shake well and spray on plants.
2. Garlic spray: Blend 5-6 garlic cloves with 1 quart of hot water and strain through cheesecloth. Add a few drops of dish soap (NOT detergent) and spray on plants.
3. Soap spray: Mix one tablespoon of liquid soap with 1 quart of water and spray on plants.

Manual Removal

If you only have a few aphids on your plants, you can remove them by hand. Use a soft brush to gently brush off the leaves of your plants and dispose of them. Be sure to check your plants regularly for new aphids.

Soil maintenance and composting

Healthy soil promotes healthy plants and reduces the impact of aphid species, pests, and diseases. Here are some soil maintenance techniques that can help control aphids:

Add compost: Composting can help improve the health of your soil by adding nutrients and beneficial microorganisms. Healthy plants can better resist pests and stave off disease. 

Rotate crops: Rotating crops can help reduce the build-up of pests by separating the preferred food source from eggs when they hatch.

Mulch: Mulching can help retain moisture in the soil and reduce the impact of pests and diseases.

Keep The Garden Clear of Debris

Removing dead or diseased plant material that could harbor them during winter is important to keep your garden free from aphids and their diseases.

Removing weeds that can provide shelter and food for aphids is also helpful. Some aphid species have alternate hosts, so keeping your garden clean and free of these hosts can reduce the number of aphids.

A garden with well-spaced plants improves air circulation, preventing the spread of aphids and other pests.

Finally, a clean garden makes it easier to spot aphids and other pests early, giving you time to take action before the infestation becomes severe.

Controlling Aphids Organically – It’s Easy but requires a bit of planning.

Organic methods will help you control aphids, but one method will likely not be the stand-alone win for your garden. Organic gardening will always start with proactively managing your plants’ health through garden soil and proper watering methods. A sick or struggling plant is like a beacon to insects welcoming them to your garden. If you take care of the plants first, it’s the first step to controlling insects like aphids.

Keeping a clean garden and ensuring a diverse ecosystem will also help protect your garden and enable your plants to protect themselves. And if those methods fail and heavy summer pest pressure persists, you still have organic pesticides and removal methods up your sleeves.

It seems like a lot of work, and it is! But growing healthy, chemical-free food for you and yours is worth the effort.

Interested in More Organic Pest Control Tips?

Check out these articles on keeping your garden pest-free, naturally:

• How to Control Cucumber Beetles
• Keeping Squirrels Out of Your Garden
• Natural Ways to Repel Rabbits
• Deer Resistant Perennials
• How to Manage Flea Beetle Infestations
• Managing Earwig Infestations