Autumn is here but there’s still time to sow seeds of leafy greens such as lettuce and kale in many parts of the country. If your vegetable gardening season ends with the last tomato or bean crop, you’re in for a treat. You can extend your harvest well into fall by sowing seeds now.
One of our favorite fall crops is kale (Brassica oleracea), the current darling of foodies and cooks. It’s rich in nutrients (vitamins A and C), it provides fiber and it’s tasty. Kale is a member of the Brassica (cabbage) family, but even if you don’t like cabbage, you may enjoy this leafy green, which can be steamed, sautéed, used in omelets, and in soup. You can simmer the leaves with potatoes, barley, and sausage in a Dutch recipe, called boerenkool. It’s really good with pork roast, too, or doused with butter or drizzled with vinegar.
Kale Loves the Cold
But the best thing about this green is that it’s well known for its exceptional cold tolerance. And the flavor just gets better and better as the season progresses. In fact, it tastes almost sweet and mild after a light frost and extended cold weather. And the seeds will germinate even if the soil temperature is only 50 degrees. Once they sprout, you can start harvesting baby kale leaves in 28 days.
On nights when the air temperature dips into the 30’s, we place a floating row cover (a lightweight spun-polyester cloth) over the plants to protect them from frost. They’re held in place with a few rocks on each corner of the cloth. Row covers are available at local garden centers, big-box stores, and online. In a pinch, you could use a cardbox box, a sheet, or a light-weight plastic tarp suspended with sticks a few inches over the plants.
Heavier weight row covers are called frost cloth. They keep the air surrounding the plants about 5 degrees warmer than the actual temperature. Come morning when the sun is out, we remove the cloth and any wilted plants perk up.
I sow kale seeds in the spring for an early crop and again in late summer and fall. In most areas, you can harvest the leaves into winter.
Grow kale in a fertile, well-drained soil that is high in organic matter. In the fall, I plant kale in pots kept close to the south and west sides of the house where the heat from the wood radiates some extra warmth at night. Kale grows best in full sun, but like other greens, will tolerate some shade. When growing edibles in pots, I use a soil-less, lightweight potting mix and I water it as soon as the surface appears dry. I sow the seeds an inch apart and 1/4-inch to a 1/2-inch deep so that the plants grow dense. If your garden center has kale transplants, you can plant them now and begin harvesting a few weeks earlier than seed-sown kale.