Did you know? This summer, if you let the sun do its handiwork, it will kill weeds and also preserve good soil microbes. Here’s how you do it: Joe Lamp’l, author of The Green Gardener’s Guide, says you should clear your bed of all vegetation (I guess that means pull out the weeds by hand) and then water the soil generously. Cover the soil with clear plastic sheeting 2 to 4 millimeters thick. Anchor the edges with rocks, blocks, or bricks. Then let the sun work on the soil for 4 to 6 weeks in the dead of summer. He says that the intense heat under the plastic sheeting, up to 165 degrees, will kill weed seeds, diseases in the soil, and nematodes.