If you thought you spotted blossoms on your rhododendron and forsythia plants just days before much of Maine was blasted by the first winter snow and sleet storm of the season, your eyes did not deceive you.
The topsy-turvy December temperatures — on Christmas, Bangor tied its record high of 54 degrees and Portland broke the record with 62 degrees — meant that some plants got confused and decided to start to bloom earlier than normal, according to University of Maine Cooperative Extension horticulturist Kate Garland.
“It’s basically jumping the gun on the next season,” Garland said, adding that the unseasonable blooms shouldn’t be a big deal to the plant in the long term.
According to the horticulturist, plants such as forsythia and rhododendrons require a certain amount of cold for the flowers to develop. Then, the blooms will open up with the right amount of warmth. This fall, both of those things happened.
“In some years, we have this wacky series of days,” Garland said. “The bud has met its chilling requirement, and all of a sudden, we get this window of enough warm degree days for that flower to open.”
The flowers that have opened will not bloom again next spring, she said. However, it doesn’t mean there won’t be flowers come spring — whenever that is.
“It’s usually not a high percentage of the flowering plants. It’s not a huge deal,” Garland said. “Those flower buds will not rebloom in the spring, but probably there will be plenty more flowers.”
Maine trees, on the other hand, do not usually flower or dramatically leaf-out drastically early.
“Our trees are very robust,” Garland said.
While some plants need the requisite chilling and warming before they burst into bloom, others, such as poinsettia, are triggered solely by the amount of daylight. Also, Garland said that some onion plants will not form a bulb unless the days are short or long enough.
“Plants are wildly confusing, and they vary from type to type,” she said. “I almost try to liken it to being a vet for thousands of species.”
Garland said that because this year has been wacky, temperature-wise, gardeners who have bulbs in the ground are encouraged to insulate the ground with material such as straw or boughs.
“We can always count on the fluctuating of temperature,” she said. “This year, it seemed to happen a little earlier.”