If you read a bottle of insecticide (any chemical designed to kill insects) it almost always says in small print, “Can be used to control aphids, cicadas, etc…”. The late great rosarian, Phil Ash would always chuckle at this and bellow, “I don’t want to control insects, I want to kill them!!” But the overuse of chemicals can have a serious impact on human health. It almost rendered my wife sterile, but that is a story for another day.
Sometimes the best inspiration for gardening can come from the movies. One of my kids’ favorites is Pixar’s “A Bug’s Life”. If you recall, in the movie, the two things that the bugs feared the most were birds and water. These are the two weapons you can use to rid your garden of aphids without using any chemicals. Let’s start with water.
Aphids have a piercing-sucking mouthpart with tiny barbs on it. When an aphid is born it might only move an inch away from its mother, jam its mouthpart into the plant tissue and remain in that one spot for the rest of its life (7-10 days). It is this inability to move after feeding begins that is the insect’s weakness for you to exploit.
Aphids can easily be killed by water. I have about 50 rose bushes that I water by hand. After I soak each rose I give the rose a “power washing”. This is done by simply forcing the water out of the hose at a high velocity with your thumb or other device. I always blast the middle of the bush and take care not to hit any flowers. Once an aphid sinks its mouthpart into a plant, the insect is completely defenseless. If you blast the aphid with water, the insect does not wash off of the plant, it gets blown apart and you have a happier rose.