This variety is usually smaller in habit and slender stemmed but is a lush growing and full-blooming hydrangea. This family of hydrangeas comes from Japan and has very serrated leaves that show lots of red and burgundy in the sun as they age. This group of hydrangeas is a great choice for locations subject to late spring frosts as they are late to leaf out and typically avoid the risk of damage. USDA zone rated 6 to 9. The Serrata hydrangeas bloom late May and bloom well into summer before aging to red and flipping upside down.