Taking preventative measures to control aphids before the growing season is always a good idea. Early and prompt treatment of any signs of a pending aphid attack is the most effective way to control these tiny insects that can do a lot of damage in the garden. How much damage can aphids do? Not only do they destroy the plants that they feast on, but they can also spread plant disease.
What are Aphids?
Aphids are tiny, soft-bodied insects that suck the sap from the stems, leaves, flowers, and sometimes even the roots of plants. They reproduce and multiply quickly—several times in a growing season in some cases, making it easy for an aphid infestation to occur.
Some aphid species are very small so they may not be noticeable right away. Signs that indicate the presence of aphids include a sticky substance coating plant stems, and leaves that are curling, brown, or decaying. Look under individual leaves as the insects tend to hide there. You may see eggs on the stem or leaf as well. These look like small dots of pepper and can vary in color. The moment you see any of these signs it’s time to act—get rid of the aphids before they get out of control.
Ways to Prevent and Control Aphid Infestations
- Natural methods: Whenever possible, grow plants and flowers that attract aphid predators and/or ward them off with their scent. Planting herbs such as mint and dill weed will attract ladybugs, which eat aphids. Plants in the onion and garlic family emit odors that aphids avoid. Zinnia, cosmos, mums, aster, and hollyhock are a few flowers that are said to deter aphids. And let the dandelions grow! Not only are they good for the bees and pollination, they also attract ladybugs.
- Natural aphid predators: Birds and insects are an effective natural combination for aphid control. Ladybugs may be innately attracted to gardens containing the flowers and plants listed above, but they may also be purchased in bulk commercially. Check with a trusted local greenhouse for recommendations on where to purchase quality ladybugs. Once your ladybugs arrive, simply set them free in your garden. They will get to work eating aphids and other pest insects in no time. Chickadees and other bird species have been known to eat aphids as well. Place birdhouses on your property to lure nesting birds in the spring and to keep them coming back season after season. Keep the birdhouses in good condition. Leaving birdseed in feeders year-round will entice chickadees and other birds to the area. They’ll feast on aphids, and as a bonus, birds in the garden are a joy to listen to and watch.
- Manual removal: Whenever possible, remove and kill aphids with your hands—gloved or bare—as soon as you notice them on your plants. If there’s a section of a plant that’s heavy with aphids, cut that section off and drop it in warm or hot soapy water to kill the aphids. Be sure to also remove any portions of plants that show signs of aphid damage to avoid the risk of spreading plant diseases.
- Sprays: Hosing off the plants with a blast of cold water can temporarily remove aphids. Organic aphid control sprays are available at garden supply centers. Be sure to follow directions on the bottle if you purchase a spray. There are many homemade remedies for aphid control—try mixing 1 quart of warm water with one 1 tsp of liquid dish soap (NOT dishwasher detergent) and mist plants lightly. Leave the spray on the plants for 10-15 minutes and then rinse it off with hose water.