The best plant foods for bees are ones completely free of toxic pesticides. But at many home garden stores, plants are regularly contaminated with poisonous pesticides — even ones with "bee-friendly" labels. Not at Berkeley Horticultural Nursery. When shopping at this family-owned retail nursery in North Berkeley, you can feel confident that your plant purchases won't inadvertently be harming urban pollinators. As part of its "Bee-Friendly Project," the nursery doesn't use or sell pesticides that experts believe are behind the alarming decline of honeybees in the US. The retailer communicates directly with its growers to ensure that the plants they are supplying to the nursery have not been treated with dangerous pesticides. While you can't always be certain that every plant is truly pesticide-free — because growers may not always know or reveal whether their seed vendors use pesticides — at Berkeley Hort, products with the "California Certified Organic" label are a 100-percent bee-friendly bet.