Q: I need something to control thrips on arugula that I grow in window pots in my apartment. Pyrethrin spray burns the leaves and eventually kills the plants. What do you suggest?

A: It’s tough to find an insecticide that can safely be used on edible plants. Spinosad (Green Light Lawn & Garden Spray) is an insect toxin derived from a naturally-occurring bacterium. It is generally considered to be an organic insecticide and it is labeled for use against thrips in gardens.