3. Soap and Water
The basic nature of mild household detergents makes them perfect for getting rid of mild to moderate aphid infestations. Dilute a few tablespoons of dish soap in a small bucket of lukewarm water and use a sponge or spray bottle to apply the mixture to plants where aphids have taken hold. Upon contact, the soap will dissolve the waxy protective coating from aphids’ bodies, dehydrating and eventually killing the insects without harming the plant. Remember to also treat the undersides of leaves where aphid eggs and larvae may be hiding!
***It is important to note that most forms of soap will also kill beneficial insects. Use caution when applying this treatment to your plants, as killing off populations of natural predator insects such as ladybugs, hoverflies, and lacewings will leave the door wide open for new colonies of aphids to move in.***
4. Neem Oil
Used in much the same way as dish soap, organic and pure Neem oil may be diluted in water and sprayed onto plants infested with aphids. The organic chemicals present in Neem oil act as a repellent against not only aphids, but also a wide array of other garden pests including mealy bugs, cabbage worms, beetles, leafminers, ants, and caterpillars. Neem oil is also effective in controlling the spread of many types of fungus that infect plants among a number of other things.
***While Neem oil won’t necessarily kill beneficial insects, it may repel them from your garden. For this reason, apply this and any other form of insecticide or repellant with care.***
5. Essential Oils
Create a cocktail of equal parts thyme, peppermint, clove, and rosemary oils- 4-5 drops of each should suffice. Mix this solution into a small spray bottle filled with water. Shake well and apply to infested plants. This potent mix of essential oils will kill most garden insect pests as well as their eggs and larvae. This combination also works great as a general purpose outdoor / indoor insect repellent!