A healthy garden is full of plants, rich soil, microorganisms and insects that coexist in a way that keeps everything in control. These natural checks and balances are important in organic gardening and prevent the need for chemical fertilizers, insecticides and weed killers.
Sometimes though, harmful insect populations can get out of control, and you may need to gently intervene to save your harvest. This year, I noticed clumps of aphids chowing down on my perennials. Then, they showed up in my veggie garden on my cool Chinese red noodle bean vines.
Aphids are very small, soft-bodies insects that literally suck the life right out of your plants. Aphids can be black, brown, yellow, orange, green, or even red. In small numbers, they are rarely fatal to plants, but a single female aphid can produce several young ‘uns, even without a mate, every single day! In just a couple of days, their populations climb dramatically leaving plants severely weakened.
Sometimes, ants and aphids infest garden plants together. Aphids produce a sticky substance called honeydew that ants love to eat. Ants sometimes import aphids to plants just for this purpose. It’s really gross, but the ants will carry the aphids to the plants, let them feed, and then stroke their bodies to help release a drop of honeydew. So, if you see a large infestation of ants on your plants, beware because aphids could come next.
Controlling aphids naturally is fairly simple because luckily, they are not high on the evolutionary hierarchy. There’s no need to resort to harmful chemical pesticides. The first line of defense should be a strong jet of water from your garden hose. Once aphids have been knocked off of your plants, they are unable to crawl back up. Be careful and don’t spray at close range or you’ll damage your plants.
You may need to spray every few days in the height of the season when infestations can grow very quickly. You probably won’t be able to clean off 100% of the aphids from your plants, but you can dramatically decrease the numbers enough to prevent further plant damage.
Another means of controlling aphids naturally is to introduce their natural predators – ladybugs. When we lived at our last house, I had severe aphid infestations on my honeysuckle and Rose of Sharon shrubs every spring. For three years, I introduced ladybugs, and they cleaned up my plants in short order. The fourth year, I saw the aphids in spring but I also saw lots of ladybug larvae already present and eating the aphids. The ladybug numbers had climbed enough that I didn’t need to introduce them again.
You can purchase ladybugs online or at your garden center. If you buy from the garden center, they will be refrigerated. Drive home right away and keep them in your fridge until dusk. Before releasing, water the affected area very well and then gently shake the ladybugs and any bedding material right onto the ground around the affected plants. That’s it! If you have kids, they’ll get a kick out of watching the bugs, too.
The only organic pest control I recommend for very persistent aphid problems is insecticidal soap. This should be an absolute last resort because it will kill all insects, good and bad, on contact. Do not use it if you’ve already released ladybugs. It will kill their tiny, and very hungry, larvae. And, only use insecticidal soap in the evening, after pollinators are no longer active.
Controlling aphids naturally isn’t difficult when you realize they are part of your garden’s ecosystem. While aphids can weaken your plants and reduce crop yields, using an organic approach beginning in spring will keep them from ruining your garden.