Plant Lettuce Now for Winter Greens
By: Shepherd Ogden
I really enjoy growing fall lettuce in my Vermont garden. Yes, it stretches the season and gives me a steady crop of crisp greens during those cold gray days, but there's more to it than that. For me, fall growing puts a whole new spin on gardening. It lets me think differently and view the plants and the weather in a new light. In spring, we start planting when the weather is cool and heading toward hot. But in the fall, it starts out warm and turns cold. So fall planting is a little bit like gardening in reverse.
Why Plant Lettuce in the Fall?
Lettuce is the perfect crop for this backward gardening exercise because it grows well even when soil temperatures are in the 40° F to 50° F range. Lettuce also grows well with fewer daily sunlight hours than almost any other crop, and mature plants can withstand air temperatures as low as 25° F. But to succeed with a steady crop of late season lettuce, you must understand the critical differences between spring and fall plantings.
How to Plant
Lettuce germinates best in cool conditions-68° F to 72° F but a fall harvest often requires planting during the heat of late summer. So you may need to sow your first crops in flats in a cool location, then transplant them to the garden. Second, unlike those of spring, fall growing conditions go downhill, as the average daily temperature falls and the daylength shortens. That means you have to adjust your succession planting schedule. In spring, sequential plantings usually catch up with each other, but in fall, harvest time slows as the season goes on, and crops sown only a week apart in September will mature two to four weeks apart in November or December. Thus, you have to sow more frequently than in the spring. Reverse gardening may seem confusing at first, but we've made it easier by compressing the USDA Hardiness Zone map to three lettuce-planting regions: Region 1 represents zones 2 to 5; Region 2 includes zones 6 and 7; Region 3 encompasses zones 8 to 10.
Wherever you garden, the basics of fall lettuce care are the same. Because crops grow more slowly in fall, a side dressing of slow-acting compost-a half-inch layer mixed lightly into the soil surface before planting-is better than a quick-release bagged fertilizer. Sow directly in the garden when temperatures are below 80° F; until then, start seeds in flats and transplant into the garden after three to four weeks.
During cold snaps, you can protect the crop with hay, straw, or leaves, but in periods of cold, wet weather, these mulches provide perfect conditions for rot and mold growth. For long-term protection, a spunbonded poly cover such as Reemay is much better. If you're trying to take a crop of lettuce through the winter for spring harvest, add an organic mulch on top of the cover, or use a cold frame-anything from a wooden crate with a storm window laid over the top to a high-tech aluminum and acrylic, self-ventilating unit.
The most important ingredient in fall lettuce success, though, is a solid knowledge of your garden's climate and the nature of the changing seasons. To me, that familiarity is one of the most satisfying aspects of fall gardening. It helps to put me in touch with the seasonal changes, and helps me, as a gardener, to stay in tune with the season.