The weather is cooler, and there are fewer mosquitoes to bother you while you're working in your garden. A fall vegetable garden comes with even more rewards. Some of the best cold-weather meals start with vegetables that flourish while the leaves turn colors; think soups, stews and stir-fried sides.
Publisher Kimberlee Williams, who lives in the Pacific Northwest, says, "I love my beets, spinach and leeks (for a great leek soup with bacon), and the only problems I've had are with carrots, which for some reason got a little soft instead of nice and crisp. Now we have a community garden, and a bunch of folks are looking forward to growing kale this fall."
Kale, turnips, Brussels sprouts, horseradish, parsnips, beets, spinach and winter squashes (butternut, acorn, buttercup, kabocha, hubbard, pumpkins, etc.) are popular choices for fall gardens and cold-weather harvesting. You should ideally plant onions, leeks, broccoli, collards and cabbage the first week of August in most climates. It's said that some vegetables taste better after the first frost, including kale and Brussels sprouts. Carrots can remain in the ground when the weather turns cold but should be harvested before the ground freezes. Many root vegetables can be left in the ground through the winter, as long as you cover them with a heavy layer of mulch; 1 to 2 feet of hay or straw is recommended.
"A frost can occur anywhere from 36 F to 32 F," according to Cornell Cooperative Extension. "A light freeze refers to temperatures between 28 F and 31 F, a moderate freeze between 24 F and 28 F, and severe freeze below 24 F." Listen to your local weather channel for frost warnings. If a frost is forecast after a period of warmer weather, then you can protect your plants by covering them, with or without stakes; a breathable fabric, such as burlap, is better than plastic. Plants will stay warmer by about 2 to 5 degrees if the fabric is not touching the plant. Cover your plants in late afternoon, and uncover them when the morning sun is up.
Most plants can survive a first frost when the temperatures before (and after) are higher. Lightly watering the ground will also help to raise the temperature in the garden, as water retains more heat than dry soil. A small amount of frost on the surface of the vegetable won't hurt most varieties. It's the internal temperature that is important; once serious frost damage occurs, the vegetable cannot be revived.
Raised bed gardens tend to dry faster after summer rains, so you can get cool-season crops planted sooner and expand your vegetable crop choices. By placing semicircle hoops over the raised bed, you can easily cover your plants to protect from frost or create a mini-greenhouse effect to extend your growing season. The raised bed allows for a softer medium for seedlings to sprout, and root vegetables, such as carrots and beets, will have more freedom to grow.
Determine your planting schedule by finding out the expected first frost date and then checking the package for the number of days the vegetable takes to go from seedling to maturity. Add two weeks to that number, and then count backward from the frost date. If the weather is still hot when you need to plant your seeds, start them indoors in a cool area before transplanting to your outdoor fall garden.
Now is the time to clean up the garden area from pests that can damage plants. Slugs like to lay eggs under the dying leaves from the summer crop and can cause a lot of damage to young vegetables. Novelist LK Hunsaker says, "Crumbled eggshells and coffee grounds help prevent slugs, and they're good for your plants."
Before planting your fall crop, clear away the remains of nonproducing summer plants, and add rich compost to the soil. Also, turn the soil bed to break up hard clumps.
Spraying plant leaves with a mild mix of hand dishwashing liquid and water can help deter other harmful insects, as well. If you choose to use commercial chemical deterrents, be sure to read the label to make sure they are not harmful on edible plants.