What is the longest flowering perennial in the UK?
Probably one of the longest flowering garden plants, hardy geraniums start flowering around May, and continue to October, depending on the variety. One of the longest flowering varieties is Geranium ‘Johnson’s blue’ (illustrated) which is also attractive to bees. Moonbeam’ Tickseed. With blooms that form in early summer and last all the way until the end of fall, ‘Moonbeam’ is the definition of a long blooming perennial.While many perennial flowers have long bloom times, the threadleaf coreopsis Moonbeam variety (Coreopsis verticillata ‘Moonbeam’) is a perennial with the longest bloom time. Moonbeam blooms early in the summer and will continue to do so until the end of the fall.