I think the problem isn't so much the brand, but cross contamination during shipping and at the stores themselves. I'm just speculating though and I've tried several brands of soil, from FoxFarm, Roots, Kellogg, Supersoil, and several generic brands. I've never got pests from the soil (knock on wood). I'm also really picky about the condition of the bags. I pretend like it helps but I really don't know. lol. I've just heard a couple of times from different people that it's cross contamination during shipping.