By Peter Collins Brown, the Bedford Citizen’s weatherman
Yes, it’s true! It appears the 2012 growing season will be history by sunrise this Saturday morning. Our first frost of the fall/winter season is waiting in the wings! Under clear skies with calm winds, Bedford could see temperatures dip as low as 27 degrees just before the sun comes up on the morning of October 13.
For those of us with tender plants outside, Friday evening should be the time to bring in any that are not rooted in the ground. Plants like chrysanthemums are very hearty, but it should be noted that temperatures this cold can take a toll on those beautiful late summer and fall blooms. Bringing thoseplants inside will allow them to stay warm and continue growth oncethey are put back outside the following day. Unfortunately, any plants that cannot be moved indoors will perish unless properly covered.
After our warm winter, spring and summer, is this cold weather hitting too early?
Oddly enough, the answer is “No.”The Boston area typically sees its first frost around October 15. Bedford, however, can see its first frost nearly a week earlier than many surrounding communities. Why is this? Bedford sits next to the Concord River, meaning we sit in a slight valley. Towns to our east and west are at higher elevations. At night, cold, dry air sinks to valley floors, making towns like Bedford five degrees colder than neighboring towns. In contrast, Boston may not see its first frost until mid-November due to the urban heat island effect caused by all of that concrete and asphalt, which absorbs heat during the day. Bedford may begin Saturday morning at 27 degrees, but Boston may only cool to 38 degrees! Even here in Bedford, we have our own microclimate! We have beautiful landscapes, but our growing season is five weeks shorter than the city.
Can there be a good side to our early cold snaps?This time, the answer is “Yes!” Although the first frost of the season puts an end to our growing season, there is a good side to the story. Mosquitoes that harbor eastern equine encephalitis (Triple-E) and West Nile virus will be killed by the cold. Bedford was visited by these mosquitoes this past summer; however, after Saturday, we will be free to enjoy any warm weather that may come later in the fall without the threat of these disease-ridden insects biting us. In fact, Indian summer, which is heralded by the first 70 degree day after the first hard frost, will likely show up by Monday!
So, don’t despair! Even though Bedfordites can’t grow any more tasty summer vegetables after this weekend, there is still plenty of great weather to enjoy, without the bugs,before Old Man Winter comes knocking on Bedford’s door.