Gardeners in the Buffalo and Western New York area have more plants to choose from than they did just a decade or two ago. The plants are genetically better, too. This is one of the big trends Ron Heimiller has seen in his career as president and head grower at Heimiller Greenhouses in Newfane. The business is celebrating its 30 anniversary. Breeders searched the world for plants that might do well in the United States and bred them for color,…