My aphid and whitefly control mission needed a plan. First I had pretty much neglected my greenhouse for a few weeks so a lot of weeds and volunteer mint came up on the floor. Both the weeds and mint were potential breeding and hiding places for more aphids and whiteflies. Since I didn't really need the mint and the weeds were just breeding more weeds I removed as many of these plants as I could.
Next step was spraying every bit of foliage in the greenhouse; even if I couldn't find any aphids or whiteflies on every plant. I chose neem oil which can now be purchased at many garden centers. The active ingredient is Azadirachtin which is a hydrophobic extract of the neem tree (Azadirachta indica) which to arid regions of India. This botanical insecticide deters feeding and interferes with the normal life cycle of insects. However, for this insecticide to be effective all foliage must be sprayed so as to leave no attractive place for the insects to land and feed.
Unlike chemical insecticides, neem doesn't kill the aphids or whiteflies instantly. So I'll have to wait until they starve because they have stopped feeding. However, I should be able to eat the vegetables right after they have been sprayed by just washing the insects off. Neem is not poisonous to humans.
Now I have reduced my aphid and whitefly population for a while but I need to monitor it with sticky traps that will capture all the flying aphids that are still alive. Especially now that weather outside the greenhouse is getting colder because the insects will now be migrating to the more hospitable climate inside the greenhouse.
