I find if I control the ants, I have far less aphid problem anywhere in the garden. One of the ways to control ants is 2 cups of sugar, 2 cups of cider vinegar, 2 cups of water in a one gallon milk jug with small holes in the lid. The holes should be large enough to allow ants in, but small enough to avoid trapping bees. I place these traps near plants that aphids seem to be fond of, basil, broccoli, cauliflower, etc. I also keep a flat dish of fresh water where broccoli and cabbage are planted. The wasps are attracted to the water, but also eat cabbage loopers and potatoe bug larvae. I change the water freqently to keep it from breeding mosquitoes, but it works well.
