I'm continuing my theme of why it's a delight to grow vegetables in the winter. As we all know, winter is a time when natural processes slow down and we feel the need to rest. This slowing-down fosters a more relaxing, less stressful growing experience. The usual summer farmer's never-ending-to-do list simply doesn't exist in winter. (Of course, back in Angela's office, the never-ending to-do list continues to grow--let me not fool you. I'm referring to the lesser pressures of winter growing, not the ten-thousand managerial tasks that magically arise during the winter.) Not only are there fewer risks to vegetable health in winter, but the veggies end up tasting better due to the cold temperatures: less stressful to grow, better taste!
While not all vegetables can survive winter temperatures, many can, creating a diverse and tasty winter farm. Most fruiting vegetables--tomatoes, eggplant, peppers, and summer squash--do not tolerate cold temperatures. If we want to enjoy them in January, we have to freeze or can them before the temperatures drop. Obviously, the array of veggies at our Winter Market do survive relatively low temperatures. Yet some are more cold tolerant than others. Vegetables that can be grown down to 26 degrees include broccoli, collards, kale, mustard greens, parsley, peas, radishes, spinach, leeks, scallions, and carrots. Others that are less cold-tolerant but can withstand a light frost include beets, lettuce, chard, arugula, Asian greens, and cilantro. You may be wondering, "What will happen to our dear plants when it's 10 degrees outside this week?" Well, we can thank our hoophouses and row covers, which keep the soil and average air temperature warmer than the damaging outside temperatures.
Have you noticed that many of the vegetables you're getting this winter are a bit sweeter than the summer veggies? That's because many of the crops increase their sugar content when they experience cold temperatures.
One study (click here) found that cabbage plants exposed to cold, non-freezing temperatures increase their sugar content, which is correlated with cold tolerance. It seems the increased sugars are part of what helps the plants survive the freezing temperatures. This physiological factor is also a real treat for us, because it makes the carrots, greens, and other vegetables taste a little more like candy!
As I mentioned, producing these sweet winter treats is far less stressful than in the summer. Water, weed, and pest pressures--the factors that keep farmers busy in hot weather--all decrease with the falling temperatures!! With the short days and cold temperatures, water evaporates at a very slow rate. When it does evaporate, it often stays in the hoophouse system, due to condensation on the plastic roof or the row cover; from there it "rains" back down on the beds. This means that once a crop is watered well in the fall, it may not need to be watered at all over the winter. Irrigation is a huge pressure during the summer, and it's a treat not to have to worry about it at all.
Weeding is an activity that could take up most of an organic farmer's time during the summer. But in winter, when the ground is not being watered and the cold temperatures mean plants grow slowly in general, the weed pressure almost ceases to exist! It takes almost no effort to keep the beds pristine, completely free of competing weeds.
Pests and diseases are another huge worry for vegetable farmers during the summer. While these pressures do still exist, there are fewer of them in the winter. I find myself battling slugs in the damp hoophouse soils, and some of the plants have suffered from diseases caused by over-watering in the fall; but overall, pests are close to non-existent. Many of the bugs die off or hibernate in the cold temperatures, and fungal diseases don't spread as rampantly in colder weather.
Fertility is another key to growing healthy vegetables. The goal is to start the plants in healthy, fertile beds in the fall, so that when microbial activity lessens in the soil in winter, there already are nutrients available to the plants.
All in all, the pressures to raise healthy plants are much less in winter. My main concern is planting them with enough time to grow to maturity and keeping them warm enough to survive! So I sincerely mean it when I encourage you to take this winter to slow down, kick back, and take your time enjoying your bites of sugar-loaded greens!
[Thank you so much for this wonderful essay, Devorah--it's a learning experience for all of us. Melinda]
