Hydrangea macrophylla

H. macrophylla ‘Summer Crush’

Get use to it… big leaf hydrangeas (Hydrangea macrophylla), also called hortensia hydrangeas, are temperamental (USDA hardiness zones 6-9). After a long winter of sub-freezing temperatures, these blue (or pink) flowering shrubs should be stunningly beautiful in spring. However, if the late winter- early spring temps flucuate wildly, grab your pruning shears.

Too most gardeners, myself included, find growing these hydrangeas totally frustrating. Bloom buds on the old wood are predictably injured two out of three springs in zone 6 eastern TN, Southwestern VA, and western NC (southern Appalachian region). Flower buds and stems are most susceptible to injury as the plants start to break dormancy in late winter, then get smacked by a sudden cold snap.

To protect against winter freeze damage: 1. site big leaf hydrangeas close to your house or a heated structure; 2. do not feed plants in the fall; 3. select better cold tolerant cultivars (varieties).

In northern climes, such as Midwest or New England states, cover big leaf hydrangeas with mulch or leaves. In late winter inspect the lower buds as the plants start to awaken. You don’t want to trap excessive moisture around the growing buds and invite diseases to the plant.

Hydrangea breeders (Bailey’s , Proven Winner’s and Spring Meadow Nurseries to list three) continue to introduce hardier bigleaf hydrangeas that bloom on both new and old wood. Old wood flowers are set on last year’s shoots and new flowers are made on current season’s growth. Do not prune hydrangeas late in the summer, as you may be removing flower buds the following spring.

Over a quarter century, Proven Winners Colorchoice™ and Bailey’s Nurseries (Endless Summer™, Bloomstruck™, and Summer Crush™ brands) have introduced new hydrangea genetics. Try short growing Let’s Dance™  series  in small gardens. Also, grow a different hydrangea species such as mountain hydrangea (H. serrata). New from PW Colorchoice is the Tuff Stuff® series of mountain hydrangeas which display superior bud hardiness and re-bloom. Tuff Stuff Ah-Ha® re-blooms heavily and has large lacecap blooms with double sepals,that are either pink or blue depending on soil (media) pH._­­­­­