Aphids: An omnipresent garden pest that will suck the sap from nearly any plant in your garden. I've seen them devour a Knockout rose bush on an 18th floor terrace in NYC just as readily as they've sunk their teeth into my backyard sweet pea vines. The goods news is, there are several safe, organic ways to get rid of them.
Release Predator Insects (ladybugs, praying mantis, green lacewing)
I recently released an army of ladybugs courtesy of Nature's Good Guys to help bring an aphid infestation under control at Greenleaf Garden. It was fascinating (and satisfying) to watch the ladybugs immediately get to work eating all those tiny green aphids. It's been over a week and not only are the aphids gone, but I still have a few ladybugs hanging around in case the aphids try to pull a fast one on us. Praying mantis and green lacewings are also very effective predator insects for keeping pests at bay or ridding a small-to-medium infestation from the garden.
Spray with Neem Oil
Another great organic solution to getting rid of aphids (and a host of other garden pests) is by spraying them with neem oil. Derived from the seeds of the neem tree, neem oil kills aphids by smothering them as opposed to applying any sort of toxin. My go-to brand is Bonide which is readily available online and in garden and hardware stores.
Coat with a Soapy Water Spray
If you'd rather make your own insecticidal soap at home, simply mix 5 tablespoons of dish soap or castile soap (make sure it's not detergent!) with 1 gallon of water and spray generously on the affected plant. It helps to do this in the morning or evening when the plant is shaded so that there is a reduced chance of leaf scorch. Be sure to coat the undersides of foliage to get to any aphids that are hiding. Like neem oil, this soapy water spray works my smothering the aphid, and may need to be reapplied a few times to rid your garden of the infestation.