Hydrangea Hangover: Island Flowers Starting To Recover After February Deep Freeze

After a warm January followed by a deep freeze in February that left hydrangeas across the island badly damaged, the iconic flowers are starting to show signs of life.

“It seems like a pretty good majority of the [deep blue Endless Summer] variety are starting to push up new flower buds, which is what they usually do this time of year,” island landscaper Steven Collette, who works for Ernst Land Design, said. “Of course, not nearly as much as they usually would, but it’s something.”

Hydrangeas rely on temperature cues to determine when to leaf out and when to die back, and the mild January left them unprepared for February’s deep freeze. The resulting reduction in flowers has been noticeable across the island, but Collette thinks almost all the plants will survive.

“A lot of the ones that looked really bad in the Spring are starting to recover. They’re trying. They’re trying really hard,” he said. “August should start to look a bit different.”

Overall, he expects about 5-10% of hydrangeas island-wide will be lost, but the cold snap only knocked out a small portion. Deer and fungus also played a role. For the most part, February’s deep freeze caused a significant reduction in flowers this summer but left the plants alive.

“We actually noticed more death with grasses. We had to replace hundreds and hundreds of grasses,” he said. “We had places where we had to replant hundreds of plants at the same house.”

Ornamental grasses such as fountain grass were hardest hit by the temperature fluctuations—and the combination of a milder winter followed by a deep freeze could become more common as a result of climate change. Scientists generally agree that winters in New England are poised to become much milder, and subsequent deep freezes may be more pronounced as well. A warm January doesn’t imply a warm February, and as the effects of climate change become more pronounced, extremes increase and variation goes up. Some scientists have termed this “Global Weirding.”

But in the short term, the hydrangeas, at least, seem likely to recover. Colette said the weather this summer has been ideal for the plants.

“If we just have a normal winter or within 10 percent of normal, this would bode really well for flower production next summer,” he said.