Hydrangeas are in full bloom, causing gardeners across New England to rejoice.
You've probably heard of this plant before, especially if you live near a garden. Hydrangeas are colorful, round flowers that are often the centerpiece of many gardeners' flower collections.
They come in a variety of colors including blue, green, pink, purple, red and white and are a popular perennial that will look especially vibrant this summer.
“This is shaping up to be a great year for hydrangeas,” says Cape Cod horticultural expert CL Fornari.
Rainy summers and warm winters are ideal for hydrangea growth.
Rainfall throughout the year is essential because plants form flower buds for the following year in mid-to-late summer. Regular rains last summer and fall, followed by a mild winter, “allowed the flower buds to survive the year and we saw an incredible number of hydrangeas bloom,” said Fornari, founder of the Cape Cod Hydrangea Festival, which is celebrating its 10th anniversary this year.
As perennial plants, hydrangeas go dormant in winter to avoid the cold, but that doesn't mean they're safe from extreme temperatures: “If they freeze below 10 degrees, they won't flower,” Fornari explains.
This doesn't mean that winters need to be unseasonably warm, we just want steady temperatures with more gradual changes, as opposed to a hard freeze where temperatures go from a relatively warm winter to suddenly freezing.
Clemson University's College of Agriculture, Forestry and Life Sciences explains the impact this way: “Freezing temperatures can damage plants by causing ice crystals to form and sudden temperature changes that can burst plant cells.”
For hydrangeas, this means flower buds will die back, something that happened across New England last year as a result of the polar vortex, Fornari says.
So what can gardeners do?
“Prayer is the best thing you can do,” Fornari says, because making hydrangeas bloom is largely beyond human control. “You just have to sit back, relax, and hope for the best,” he says.
Not all hydrangeas are delicate, but the hugely popular blue mopheads rely heavily on this particular combination of factors that change from year to year.
“When people are worried about whether there will be a bumper crop of hydrangeas this year, they're talking about mophead hydrangeas and lacecap hydrangeas,” Fornari said.
It has also become a staple of coastal New England, where the naturally acidic soil helps it retain its blue color and the warm winter and cool summer temperatures of the coastal areas encourage flowering.
