Touch wood, I haven't needed to use anything this whole grow! (except giving the whole grow area a generous dusting of diatomaceous earth before planting seeds) Plants are healthy and full of predatory bugs; praying mantises, lynx spiders, jumping spiders, wolf spiders, and the occasional ladybird. I did apply quite a thick layer of mulch and keep any weeds out. I even saw a Western Cape leopard toad under one of the plants.