Saturday, February 25, 2012
I've been doing a bit of research on the climate here in Burlington, Vermont. According to the 2012 USDA Plant Hardiness Zone Map, Burlington lies within a narrow band of light blue surrounding Lake Chaplain. The 1990 map had listed the area as zone 4b but now it appears we are officially zone 5a. While this warming trend may benefit the growers in our area, I can't help but wonder what devastating effects it may have on other parts of the world already prone to such things as drought or flooding.
As a gardener, I must admit that I like the sound of 'zone 5a' much better than 'zone 4b'. Whenever I look at a fruit tree catalog these days, I always get discouraged to see the number of varieties that are only suitable for zone 5 or higher, like most sweet cherries and Asian pears. (I particularly love Fedco's Tree catalog, which gives great advice on specific varieties that will grow best here in New England.) If we decide to remain here for the long haul, I would definitely try to grow some marginally suitable varieties.
When researching Burlington's average frost dates, I found this great chart put out by National Weather Service. I'm horrible at interpreting these things but if I'm reading this one correctly, it seems that May 7th is the median frost free date. We have a 25% chance of frost on May 13th and only a 10% chance on May 19th.
Fast forward to fall, our median first frost date is October 6th with a 25% change of frost on September 29th and a 10% on September 25th.
So how does this compare to what we've been accustomed to our zone 6a garden in northeastern Massacusetts? Well, it looks like we'll be losing about 2 weeks of frost-free days at each end of the growing season (one less month of growing). What's even more striking are the average maximum temperatures during the summer months here in Burlington (June - 75.8 F, July - 81.2 F, August - 77.9 F), which seems much milder than what we're used to.
I imagine my first year of growing here in Vermont should be an interesting one. I'll be curious to see how our tomatoes, peppers and melons fair this year. At the very least, it will be a learning experience for this veggie gardener.