Although Labor Day is imminent, there’s no reason to put your vegetable garden to bed just yet. From late August through September, I make the most of the Chicago area growing season by planting cool-season edibles — the same ones that I grow in spring.

Right now, I’m sowing seeds of leafy greens — bok choy, lettuce, Swiss chard, ‘leaf’ broccoli and kale  — as well as radishes, carrots and beets for my fall harvest. Seeds sown now germinate quickly because the soil is still warm and many edibles, such as radishes, can be harvested in as little as 28 days or so. And some greens, like kale, become sweeter as the temperatures drop.

Lacinato Kale / Dinosaur Kale   (Photo by Nina Koziol)

Which Cool-Season Edibles to Grow in the Fall

Cool-season crops prefer sunshine and cooler air temperatures. When grown in the summer heat, cool-season veggies tend to become bitter. Some, like lettuce, will send up flowers and produce seeds instead of sweet-tasting leaves

For lettuce, chard, kale and beets which have shallow roots, I sow their seeds in pots filled with soil-less potting mix or in four raised beds. In our largest bed, a 20’ x 55’ vegetable garden, I pull out rows of spent beans, squash and tomatoes, cultivate the soil, add a granular fertilizer, and then rake the planting bed smooth. When sowing seeds in a bed, I use a bamboo stake or long straight stick positioned on the ground to keep the rows evenly spaced.

Use Days to Harvest to Govern Your Choice of Plants

Choose crops that will mature just as the weather turns cold. The “days to harvest” on a seed packet refers to how long it takes from the time the seed germinates and sprouts leaves to the time when it’s ready for harvest. Germination can be as little as a few days to two weeks from the time you sow the seeds. Fall germination often happens quickly in our garden because of the warm soil.

Radishes are one of the fastest cool-season crops we grow. Some can be harvested in just under four weeks. I pick them when the roots are still small and tender. Don’t wait until they’re the size of a golf ball, otherwise they’ll be woody and spicy-hot.

I also grow nutritious and tasty beet ‘greens’ that can be harvested in 32 days. The beet roots take a bit longer — up to 55 days — but they tolerate cold weather. I harvest them when the roots are small and tender — the size of a golf ball. The same goes for carrots. Because our soil is clay-based, I grow the smaller carrot varieties, like ‘Thumbelina,’ which is round, and Adelaide, which reaches just three inches long.

Swiss Chard   (Photo by Nina Koziol)

Rather than grow lettuce or kale in individual pots or in a seed flat, I often ‘broadcast’ the seeds over moistened soil-less potting mix, patting them gently into the surface. Soil-less potting mix is often peat-based and dries out quickly, so I lightly spray the surface with water to keep it moist while waiting for the seeds to germinate. Want to grow kale? Click here.

When the leaf lettuce and kale leaves are about 4 inches tall, I use kitchen scissors to harvest enough for a meal. This allows the plant to sprout more leaves so you have a continuous supply until there’s a hard freeze. If you’re lucky enough to have a well-stocked garden center nearby, you may be able to purchase transplants of kale, beets or lettuce. Transplants can give you a head start on the fall harvest.

Know Your Fall Frost Date

We garden in Zone 5 which is near to the southern tip of Lake Michigan. The average date for our first fall frost is October 15. In some years, the first frost has occurred much later, even into November. Click to learn more about hardiness zones.

To plan my fall harvest, I use a calendar and count backwards from November 1^st. If lettuce seeds take a few days to germinate and 30 days to begin harvesting, that brings me back to October 1^st. However, I take into consideration that the daylight grows shorter each day in the fall. So, I begin sowing seeds in early September. Simply count backward from your first average fall frost date to figure out when you should sow seeds for a harvest of fall crops.

Extend the Season by Protecting Against Frost

Keep an eye on the weather especially with regard to the predicted evening low temperatures in your area.  When night time temperatures are predicted to fall into the 30’s, I make sure the plants are covered by dusk. When frost threatens, I cover edibles growing in the ground with a lightweight frost cloth. Frost cloth is made of spun polyester and keeps the air around plants about 3 to 5 degrees warmer than the surrounding air. That can keep lettuce and other tender leafy greens from freezing.

I’ve covered Swiss chard with frost cloth when the night time temperatures dipped into the upper 20’s. The next morning, I removed the cloth and the leaves perked right up in the sunshine. Edibles that are grown in pots I cover with an inverted plastic pot or I will slip a garbage bag over the entire pot. Cardboard boxes, or an old sheet, will provide similar protection. Remove the covers the next day when the sun is out, or the temperatures rises.

Ideas About What to Do with Your Cool-Season Edibles Harvest

Thanks to Renée Shepherd (reneesgarden.com) for sharing her bok choy and Swiss chard recipes from her cookbooks, ‘Recipes From a Kitchen Garden,’ and ‘More Recipes from a Kitchen Garden.’

Milanese-Style Chard

1 bunch (1 pound) Swiss chard

2 T olive oil

1 clove garlic, minced

6 scallions, thinly sliced

2 T chopped fresh parsley

1/4 cup chopped fresh basil

Pinch of nutmeg

1/4 cup chopped prosciutto or ham

2 T freshly grated Parmesan cheese

Salt and freshly ground pepper to taste

Garnish:  2 T toasted pine nuts or chopped walnuts

Trim the chard, discard tough stems and coarsely chop. In a large, deep skillet, heat olive oil, add garlic and scallions and sauté until softened and fragrant, 2 to 3 minutes. Add chard, parsley, basil, nutmeg, prosciutto or ham, and mix well together. Cover the skillet and cook over medium heat until tender and wilted, 3 to 5 minutes. Mix in Parmesan cheese. Add salt and pepper to taste. Garnish with nuts. Serves 4 to 6.

Orzo, Chard and Squash Casserole

1 1/2 cups orzo (rice-shaped pasta)

1 T butter

1/4 cup chopped fresh green basil

1/2 cup grated Muenster cheese

Freshly ground pepper to taste

1 T olive oil

2 medium zucchinis, quartered lengthwise, cut into 1/4-inch slices

2 1/2 cups sliced mushrooms

10 large leaves of steamed chard, coarsely chopped and drained

2 cloves of garlic, minced

1 T drained capers

Salt to taste

Freshly grated Parmesan cheese

Bring a large pot of lightly salted water to a boil. Add orzo and reduce heat, cooking until orzo is tender, about 10 to 12 minutes. Drain, add butter, basil, Muenster cheese and freshly ground pepper. Set aside. In a large skillet, heat oil, add zucchini and mushrooms and sauté until almost tender, stirring frequently for 3 to 5 minutes. Add chopped chard and garlic. Continue cooking, stirring frequently until zucchini is soft.  Stir in capers. Toss vegetables with orzo and add salt to taste. Sprinkle with Parmesan cheese.

Fall Cool-Season Edibles – A Few Final Words

Take advantage of these cooler autumn days by growing more edibles. You’ll discover that it’s super easy and kind to your food budget. Besides, there’s nothing fresher than a salad made from greens you grew and harvested yourself. Bon Appétit!