Aphids -- those little sap-sucking, honeydew-excreting pests -- can definitely spell trouble for your garden. The good news is that there are several reliable organic methods for dealing with the little buggers. Here are a few of my favorites.
What Are Aphids, Exactly?
Aphids are soft-bodied insects, about a tenth of an inch long. They're typically green or black, though you may also run into gray or black ones in your garden, depending upon where you live. I wrote an article about identifying aphids on my About.com site.
The problem with aphids is that they suck the sap from the stems and leaves of your plant. This can weaken the plant, but, even worse, they also spread diseases as they move from plant to plant. And, they reproduce quickly!
How to Control Aphids Organically
Here are some tried-and-true organic methods for getting rid of aphids:
1. If you have a small infestation, simply wipe the aphids off with your hand or a soft cloth. Check back every day or two and repeat until you stop seeing them.
2. A blast of water from the hose is often all you need to get rid of aphids. Again, you'll want to repeat this after a couple of days if you see any more aphids on your plants.
3. Insecticidal soap works very well on aphids, and is a good choice if you find that wiping or spraying them off with water just isn't cutting it. Make sure you get the undersides of the leaves, too -- that's often where they congregate.
4. Homemade sprays, such as those made from tomato leaves or garlic oil, work very well on even large aphid infestations. You'll want to apply these treatments when there's no rain in the forecast, and out of strong sunlight (morning is a good time to do this.) Also, you'll want to keep in mind that these are non-selective pesticides, so they will harm any beneficials in the area as well -- use them sparingly. I have recipes for both the tomato leaf spray and the garlic oil spray here: Homemade Aphid Spray Recipes.
5. Consider introducing beneficial insects, especially ladybugs and their larvae, into your garden. They are voracious predators and will clean up an aphid infestation in no time.
Despite what I recently read on another Mother Earth News blog, keeping ants out of your garden is NOT an effective aphid control. While we do know that some species of ants "farm" aphids to harvest the sweet honeydew they excrete, and that they can, on occasion, carry the aphids to plants to ensure that the honeydew supply keeps coming, it's unlikely that they're bringing aphids into your garden. Most often, the aphids are there first, and the ants are attracted to the sweet honeydew they produce. Leave the ants alone! First off, the idea of keeping ants out of your garden is just laughable -- they're everywhere! And more importantly, it's ridiculous to spend your time trying to rid your garden of ants (which are actually very useful decomposers and predators in their own right) to prevent them from maybe, possibly, bringing aphids into your garden. There are much more effective, and more eco-friendly ways, to spend our time in the garden.
What is your favorite organic control for aphids?