It used to be that if you lived in Alaska and lusted for mini orchids, or if your home was in Georgia but your heart was with rare desert cactus, you were out of luck. Not anymore, thanks to the fact that so many plant clearinghouses and specialist growers have gone online and will ship high-quality specimens nationwide—like the mosses pictured above from Moss Acres, growers of garden and terrarium mosses, which are mailed dry and ready for hydration. The websites themselves are a pleasure to peruse, with gorgeous photographs and a wealth of information about the plants they provide; many also offer expert advice via e-mail and phone. How do you find the particular online source that sells just the succulent or edible plant you covet? Go to davesgarden.com to trawl the Garden Watch Dog, an online directory of over 7,100 mail-order plant sources. A selection of our favorites is featured on the following pages.