A visit to the local garden center this weekend revealed dozens of chemical products designed to rid our plants of the tiny little pests known as aphids. And in an attempt to make us feel better about our genocidal efforts, some of these products double as both a plant fertilizer as well as harbinger of doom for minute insects. How nice! Truth be told, aphids often don’t pose a serious threat to the health of our plants. Sure, they nibble here and there and suck a little sap, but compared to a single, voracious predator like a Japanese beetle, aphids are lightweights. The more pressing concern is that an infestation of aphids is just plain ugly to look at, especially when thousands are swarming a rosebush from top to bottom. So what’s a gardener to do? (Especially if you eschew commercial chemical solutions). Try these simple, more natural alternatives first:
If you’re not completely grossed out by the idea of squishing bugs… go ahead and pick them off your roses and give ’em a little pinch to send them to the afterlife. Check the bottoms of leaves too, where they like to hide out. If this leaves you with a guilty conscience, you can rest assured that aphids are far from being an endangered species. They’ll be back and swarming again next year. But unless you have a lot of time on your hands, this method isn’t practical for larger infestations.
If your infestation is limited to one section of your plant, it’s okay to trim off affected buds or canes and discard them.
No joke, shaking aphids off your rose bushes works… to a degree. The tricky part is shaking or tapping vigorously enough without damaging the plants themselves. Using a brush works as well. Aphids can hold on pretty tightly, but they’re not terribly strong climbers. The ones that fall to the ground will likely be eaten by predators or die of exposure long before they get a chance to climb back up the host plant.
You may have noticed that aphid infestations have been mostly washed away after a good, hard rain. You can recreate that vanishing act with a garden hose, knocking them loose with a well-aimed stream of water. Just be sure to keep the pressure low so as to not damage the plant. Spray the bottoms of leaves too, and rinse-and-repeat every day as long as necessary.
Predatory insects like ladybugs or preying mantis have voracious appetites, eating hundreds of smaller insects every day. If you don’t have a plethora of predators already in your yard, these can be purchased from your local nursery or online (it’s unlikely big-box garden centers will stock them). Natural predators take longer to see results, but they do all the hard work for you, and it’s an ongoing solution.
As much as we eschew chemicals, sometimes they’re a necessary evil. A nicer alternative to store-bought products (and potentially more friendly for the environment) is a simple solution of dish soap and water. In fact, dish soap is a common ingredient in many do-it-yourself gardening recipes. A little goes a long, long way and only 1 or 2 tablespoons per gallon is sufficient. More soap than that will kill plants as well as pests.