As the warm, humid weather roles in and the plants and trees fill out, bugs are hatching in masses. They descend on our gardens and our homes looking for food and water. In large numbers the “intruders” can threaten the structural stability of buildings, contaminate food supplies, and pose health risks. Reports in the local national news suggest that mild winter we had will likely lead to higher than average insect populations this summer, and extra precautions may be required to fortify our homes and protect our bodies— particularly from mosquitos and ticks, which are known to carry disease. Those of who grow food fight these tiny enemies on yet another frontier. These next several posts will be about my attempts at chemical-free, trash-free pest control.
Above is a calendula plant from my garden. If you look closely you can see that the bud and the new leaves are covered with aphids. If I leave the parasites untouched, they will most likely devour the plant, so I am forced to take action. I want to choose a method of extermination or deterrence that is natural and effective.
I did some research and I found a ton of useful information. One fact that really caught my attention is that ants “farm” aphids for the honeydew they produce. The ants will actually keep the aphids in their nests during the winter and then bring them out to host plants in the spring. The ants will carry the aphids around from plant to plant to continue feeding. I have always noticed little sugar ants near and around aphids, but I never knew what they were up to! I have seen a ton of ants around the property I live on—in fact I’m also working finding ways of keeping them out of the apartment (more on this soon). So it turns out, one line of defense against the aphids is to figure out how to keep ants away.
Other natural aphid repellent tricks include:
Squashing a few aphids around the infested plants to release a chemical signal that makes the other aphids drop from the plants and leave.
Sprinkling a barrier of charcoal powder, calcium dust, or bonemeal around the base of the plant.
A mild soap spray can be used to strip them of their protective wax coating, dehydrating them. Mix 1 tablespoon of Castile soap to 1 gallon of warm water. Adding a teaspoon of neem oil to that mix can make it more potent. To the aphids, the neem oil has a bitter taste, so they will not eat the leaves treated with it. And the oil will prevent the larvae from growing into adults. I’ve used this mixture in the past on my tomato plants and have found it to be effective, but I’m not too keen on using the neem oil directly on the edible parts of plants because it’s difficult to wash off. For this reason I avoid using it on herbs.
Burying shredded banana peels at the base of infested plant seems to be method that many gardeners swear by. The peels give the plants a shot of potassium too. However, I do wonder if this trick is not recommended if you have an ant problem!
A forceful spray of water is often enough to knock the aphids off the plant and may discourage the ants as well, but this is only a temporary fix.