Nova Scotia has been experiencing a warm, snow-free winter. I’m itching to get my hands in the soil and start planting spring greens. The skies are blue and the days feel warm, but is it too early to plant seeds?
I have a couple of great books by Eliot Coleman, that explains the way it works. While the sun is important for plants to grow, the day length is the deciding factor for when to plant seeds. In The Winter Harvest Handbook, Coleman states that:
“the period during which plant growth slows down significantly begins when day length drops below ten hours. This is the point at which the overall light energy diminishes to the extent that it significantly affects the rate of plant growth. Growth remains slow until February, when the plants resume growing vigorously in response to the day length becoming longer than ten hours and overall light energy becoming adequate again."
It’s all to do with lines of latitude.
My garden sits on the 44th parallel, the same as Avignon, France, and Genoa, Italy. The magic date for me is 5th February. On that date, the day is 10 hours long. From then on, until mid-summer, the days will keep getting longer. That doesn’t mean I can expect my seeds to grow without protection from harsh winds and cold snow. I grow spring greens under cover, in a greenhouse to give them a fighting chance. My greenhouse is unheated so I like to keep a plastic cover handy, for an extra layer of insulation during periods of extreme cold. If you don’t have a greenhouse, a cold frame will work just as well.
Cold frames don’t have to be expensive. A cold frame is basically a bottomless box - 8 to 12 inches high at the back and 6 to 8 inches high at the front and covered with glass panels. They can be made from old windows, doors or even straw bales.
Last fall, I planted salad crops in my greenhouse. They gave us wonderful salads and kept producing until mid-November. After 10th November the number of daylight hours in my garden is less than ten. At that point, plants stop growing.
Hardy plants such as spinach and kale don’t die but enter a period of dormancy, waiting for the sun to return. In the morning after a cold night, the plants look frozen and shrivelled. Once the greenhouse warms up in the afternoon they seem to spring back to life. I have been picking spinach, mesclun mix, arugula, swiss chard and baby pac choi through the winter. Since the plants aren’t growing I can’t pick too much; just enough for a small salad occasionally.
By early February, the mesclun salad mix and arugula were looking very raggedy, so I picked a final salad and fed the remainder to the chickens. I cleaned the soil and planted new seeds in their place; radishes, arugula, and mesclun mix.
The spinach, chard and pac choi are still looking perky. I weeded and watered them and left them to grow. I’m hoping that in a few weeks I’ll be picking spring greens.
If you want to know more about extending the gardening season, I recommend these two books by Eliot Coleman.