Few shrubs provide as much seasonal interest as hydrangeas, regardless of cultivar. Starting in early summer, they bloom abundantly and with longevity, persevering right through the hottest days and the worst downpours of summer. The flower heads are composed of hardy structures more akin to paper than petals, called bracts. Mophead varieties are mostly dense clusters of bracts. Lacecap forms have an outer layer of larger bracts that encircle tiny, fertile florets nestled in the center. Because bracts are so sturdy, the blooms last all summer. Drying them for arrangements can extend the season of enjoymenr even longer.