Aphids, also known as greenflies or plant lice are tiny, less than 1/4″ long. They range in color from light green, black, white, brown. gray or yellow. They suck the sap of plants thus weakening and damaging them. They can also spread disease and viruses from plant to plant. They are usually found on the backs of leaves, bases of stems or on flower buds or fruit. They secret a sticky substance called honeydew that ants love. If the honeydew is not collected by ants, then it too can cause issues for your plants by becoming black sooty mold fungus. They are slow moving and have many natural predators but they multiply quickly.
To control aphids a combination of methods and applications works best.
*water- spray aphids off of well established plants with a strong jet of water. This works best before a full infestation occurs.
*by hand- knock or rub off the aphids with gloved hands and place them in a bucket of soapy water to kill them
*pruning- prune any heavily infected areas and dispose
*soap & water-mix a few tablespoons of pure liquid soap, such as Castile soap in a bucket of water. Apply to infected plants by either a sponge or squirt bottle. The soap dissolves a protective outer layer on the aphids, thus killing them but won’t harm beneficial bugs.
*essential oils- 4-5 drops of peppermint, clove, rosemary and thyme mixed with water and applied to plants with a squirt bottle
*neem oil- the organic compounds in neem oil repel aphids, mealy bugs, cabbage worms, beetles, leaf miners, ants and various types of caterpillars. It may also repel beneficial insects. Neem is also effective in controlling different types of fungus.
*predator bugs- lady bugs and green lacewings eat aphids. The larval stage of ladybugs eat far more aphids than adults do. Plant clover, mint, dill, fennel and yarrow to keep those good bugs happy.
*birds- provide housing for bug eating birds such as wrens and chickadees and they will repay you with bug control.
*companion planting- plant catnip, garlic, chives, onion and allium to repel aphids
*trap plants- plant zinnias, dahlias, cosmos, asters, mustard and nasturtium as “traps” to lure the aphids away from your vegetable plants.