Up north, these hydrangeas bloom later and the nights cool off sooner. Those cool nights trigger the color change. If they don’t arrive until late September and the weather is dry, flowers often turn tan instead. They’re still attractive, especially combined with yellow fall foliage.Panicle hydrangea blooms on new growth. So you won’t lose a year’s flowers to cold winters or pruning at the wrong time. The best time to prune is late winter (removing last year’s dried blooms is optional). Most of the new selections grow 4 to 6 feet tall and wide. Feel free to shorten plants that grow too tall.This unique panicle hydrangea revolutionized landscaping across North America. Huge, football-shaped flowers open in an elegant celadon green that looks fresh and clean in summer’s heat. The blooms age to an array of pink, red, and burgundy which persists through frost for months of irresistible flowers. You can use ‘Limelight’ hydrangea just about any way you can imagine: as a showy flowering hedge, to screen off air conditioners, as an attention-getting specimen, in containers, flower gardens, or anywhere around your home. A long-time favorite of professional florists, it also makes an excellent cut flower, fresh or dried.