Rivergate Garden Center, Madison

If geneticist and horticulturalist Gregor Mendel were still alive today, he would marvel at Rivergate Garden Center. Owner Jonathan Buck fills the nursery with plants from breeders such as the aptly named Proven Winners and the Conard-Pyle Co., which has been developing hybrid roses since 1897. From spring through the moment when the world's executive producers decide it's winter, the center is rampant with blossoming roses, lipstick-red weigela, and violet butterfly bushes engineered to expend energy continuously in colorful abandon. These plants also require less maintenance, as their stems resist frost and mildew and quit growing once they have reached a manageable, predetermined size.