On Friday, Saturday and Sunday nights, the mercury dropped to freezing or below; last night was not expected to be any warmer. Now there’s news that a wintry mix could kick off rain on Wednesday. With this frosty spell all settled in, is the District’s most precious spring resource– cherry blossoms – in danger of dropping dead?
It’s a valid concern. The prunus genus, which covers cherries as well as plums, peaches and other globose drupe-bearing plants, is not the hardiest tree in the forest. Its bark is thin and its sap starts running earlier in the year than most fruit trees. That makes the plant vulnerable to the wild temperature swings that characterize March.
“Once they get going in the spring, with their juices flowing and the trees starting to bud out, cold weather sort of takes them by surprise. It’s sort of like walking outside while naked,” says Rusty Russell, a Smithsonian Institution botanist.
Russell says that the way the blossoms are constructed adds another layer of susceptibility in the cherry tree’s weather armor.
“The blossoms themselves are sort of fragile,” he says. “It doesn’t take much for the moisture in the cells to crystallize and cause rapid deterioration of the petals.”
During an especially cool spring, the odds are pretty good that the trees will not experience the most glorious blossoming possible. Freeze-shocked petals can appear brown and quite unsightly.