Friday, August 9, 2013

Step Two: Start winter greens from seed

The plan:
1) build and install one permanent, in-ground cold frame
2) start winter greens from seed
3) transplant the seedlings into the cold-frame
4) enjoy fresh mixed greens all winter!

After putting the cold frame into the ground, the next step is germinating seed.  Although the cold frame helps to ameliorate the freezing temperatures of winter, it isn't a heated greenhouse - careful thought has to be given as to the choice of greens to overwinter.  Some plants are more cold tolerant than others - mache and kale are far more tolerate of cold than tomatoes and watermelon - and even within a species, certain varieties may be particularly well-suited to cold-weather culture.

Given the increased interest in all season gardening, there are many gardening companies that are beginning to respond to customer demand by providing more cold-tolerate vegetable varieties.  With the  help of the internet and some postage stamps, everyone can have access to an almost unlimited selection of heirloom, traditional and modern veggies.

Some of my favourite sources include:

For this experiment, my winter green will be various cultivars of lettuce.  Lettuce is easy to grow, versatile to use, and many varieties ideal for winter cropping can be found.  Started from seed a few months before the cold sets in, lettuce is transplanted into the cold frames to grow.  The lettuce makes its gains during the day, and if frost threatens overnight, the cold frames can be closed.  Once the temperature has dropped below freezing during the day and the daylight hours have shortened considerably, the lettuce will stop growing, but the plants can be preserved - as though within a refrigerator crisper - in the cold frames all winter.

I have chosen three varieties of leaf lettuce, two varieties of butterhead lettuce and probably the finest winter gardening romaine available.  The seeds come from Hawthorne Farms, a Palmerston, ON company that is new to me.  (I love the old-fashioned feel to the brown paper seed packets and the wood-cut style printing.)  Because lettuce germinates best at relatively cool temperatures (21-24 C), the best approach is not sowing it directly in the cold frames in summer - the seed would languish in our hot sun.

Instead, I germinate it in the basement under grow lights, where the ambient temperature hovers right around the ideal.  Remember to label your plantings - it's incredibly easy to lose track of what you've put where!

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