"Perennials are the most challenging and rewarding of all garden plants, and most gardeners need all the help they can get to grow them well. Perennials emerge from the ground in early spring, grow to full height, bloom, bear fruit, and then disappear with the first frost, only to do the same thing the following year and again the next. Add this to the fact that for the first year or two, perennials don't do much above the ground (they a ..."