This astilbe is ‘Rhapsody’, but the flowers will look much the same on other varieties. The difference between the varieties is the height of the plant. Photo courtesy Benary Seeds. by Connie Oswald Stofko Five varieties of astilbe, one new groundcover and one new true blue flower. That’s what you’ll see in this article, but there will be many more varieties in the 69-cent perennial sale at Mischler’s Florist and Greenhouses, 118 South Forest Rd., Williamsville. Mark your calendar: The…