Fall gardening is a bit of a misnomer - instead of doing most of your gardening in the fall, fall gardens need to be planted in late summer (mid-July to August). Plants need those warm, sunny days to start growing well. But if you get your timing right, you can happily harvest all fall and winter. Here are some tips to get you off to a good start. The following content also has some reference value for raised garden beds.
Fall planting: Asian greens (bok choy, Chinese cabbage, mustard greens, etc.), chicory, chicory, mustard greens, lettuce, green Onions, spinach, arugula, Swiss chard, autumn radishes, and even peas are all good options for late summer planting and harvesting by November (check the number of growing days required, which should be listed on the seed packet). Many of them also overwinter if your area has a mild climate (as low as Zone 8). Chicory, for example, can stay under the snow for a week or two and come out looking great.
Choose plants that will survive the winter: Depending on your climate, this includes kale, broccoli, collard greens, beets, and carrots (in severe climates and prolonged cold temperatures, this may not be possible without a season extension device). The plants need warm weather to start growing, but once they reach a reasonable size, they persist through the winter and start growing again for an early spring harvest. If you plant in July, there is time to start with seeds, but by August you will want to choose seedlings for a better start to the season. Some crops, like garlic, need to be planted in the fall to have a full growing cycle. You can also plant autumn Onions in warm garden areas.
Choose plants that will survive the winter: Depending on your climate, this includes kale, broccoli, collard greens, beets, and carrots (in severe climates and prolonged cold temperatures, this may not be possible without a season extension device). The plants need warm weather to start growing, but once they reach a reasonable size, they persist through the winter and start growing again for an early spring harvest. If you plant in July, there is time to start with seeds, but by August you will want to choose seedlings for a better start to the season. Some crops, like garlic, need to be planted in the fall to have a full growing cycle. You can also plant autumn Onions in warm garden areas.
Consider herbs: Summer may be over for basil, but many herbs continue to grow in the fall. Some herbs, like cilantro, even prefer cooler weather. Other options to consider are oregano, parsley, rosemary, thyme and sage. Fresh herbs are a great way to refresh yourself when cooking in cold weather.
Interplanting: If you have limited garden bed space but still want to plant your garden in the fall, consider planting between rows of summer crops. Lettuce, radishes, cilantro, or green Onions can be planted between beans or other summer foods. When the seedlings are very large and the beans are ready, you can cut them back to the soil line and let the new seedlings take over.
Plant deeper: If you plant in warm late summer weather, plant twice as deep as in spring (some seeds won't germinate if they get too hot, so depth is important). Keeping the seeds constantly moist is also important for germination. By the end of the summer, however, the soil becomes warmer and drier, so water it regularly - more often than you plant in the spring.
Use a Season extender: In cool weather gardening, using equipment to extend the season can be a game changer. Examples include greenhouses and cold frames, which use plastic or glass to trap and preserve heat (look for Canadian gardening writer Niki Jabbour, an expert on cold frames winter gardening, for more information). If such large-scale infrastructure is not possible, or you do not wish to have a permanent structure in your garden, the best solution is a poly tunnel or clock. Clocks, in particular, are small, light and easy to carry. They provide extra warmth and protection from weather and pests. Make sure to have an air flow valve to protect against mold or other fungal diseases. Cloches can act as a small, temporary, and portable greenhouse for plants that need a little more protection or warmth.
A cloche, cold frame, or unheated greenhouse will not fully protect plants in case of a hard frost. Insulation would also be required for protection in extended sub-freezing temperatures.
Trim the soil: Summer garden crops use up most of the nutrients in the soil, so when you plant fall garden crops, it's also a good time to replace some nutrients. Use fertilizer or compost, but consider doing a soil test at this time so you can better calibrate what is needed. If late summer or fall is too busy for soil testing, add it to the list of winter chores so you can prepare for gardening next spring.
Consider a cover crop: If you don't want to grow edible crops, consider planting a cover crop that will protect your soil structure, prevent erosion, and return nitrogen as you chop up your greens and turn them into soil in early spring. Good choices are crimson clover, veal peas, winter peas, and broad beans (pea green and broad beans are even edible). Cover crops are sometimes called "green mulch".
Mulch: The soil needs to be mulched - if you don't, the soil will try to cover itself with weeds. If you don't grow edible crops, or grow cover crops, the last option is mulch. This can be made from dried, chopped leaves or straw or salt marsh hay (just make sure it is sprinkled with grass seed on your planting bed). You can also cover flower beds in your garden with burris or compost, pine needles, cocoa shells, newspaper or cardboard (remove in the spring). When spring comes, you'll be glad you did.
Make compost: As you plant your fall garden and pull out the current summer crops, you can make compost from yard waste. Dried leaves, flowered pumpkin vines, chopped grass clippings (if planted without pesticides) or kale stems are all good compost materials. Composting is a science in itself, but if you mix it up, come spring you'll have a nice soil conditioner to decorate your garden bed and start the cycle all over again.
