As crazy as it sounds, near 4th of July is when gardeners start planting their winter crops. If the timing seems odd, think of it this way; the longest day of the year in the Northern hemisphere is June 21st. Since most plants get their energy from sunlight (plants get only water and trace nutrients such as iron from soil, except in special circumstances), the weeks right before and after summer solstice is like an all-you-can-eat buffet for plants. Also, the length of daylight doesn’t change linearly each day, which means that each day isn’t just 2 minutes shorter. Near solstice the length of daylight barely changes each day, but near equinox it changes by several minutes each day.
Also, as we move away from the summer solstice, the angle of the sun becomes less direct, which means that plants are getting even less useable light- just like how you are unlikely to get a sunburn late in the day or at a Seattle beach in November (as long as there isn’t snow), even if you’re lounging scantily clad in full sun. August may seem like the most summery time of year in Seattle, but by late August, plants are getting quite two and a half less hours of daylight than in June. (Of course, if it rains all of June, and there are clear skies during August, that skews things a bit.) This all means that if plants miss out on June or July, they miss out on the time when they can gobble up the energy they’ll need for the winter. Crops that are harvested in winter, or overwinter to be harvested in spring, take much longer to mature than their summer cousins, because they grow so slowly during short days and weak light.
Here’s what I’ll be growing this winter (all available from Territorial Seed Company):
- Merida Carrots & Autumn King Carrots
- Purple Sprouting Broccoli & Purple Cape Cauliflower
- Avalanche Snow Peas
- Arctic King Butterhead Lettuce, Miner’s Lettuce, & Vit (Mache)
- Ching-Chiang Pac Choi, Giant Winter Spinach, & Fordhook Giant Swiss Chard
If anyone has experience growing these varieties, or general tips for winter gardening, I’d love to hear about it!