Fall weather has been toying with us this year, but sooner or later it’ll stick around, and all of our warm weather crops like tomatoes and peppers will be done for the season. If you’re anything like me, you might feel a little bit “gardened out” at this point in the year and feel some relief at the thought of frosty weather on the horizon. But I know there are plenty of those among us that look for ways to keep their garden going just a little longer.
If you are a vegetable gardener, you can harvest some crops into the winter months with a little prep work now. Root crops like carrots, beets, and turnips can stay in the ground well after the first frost. Add a heavy layer of mulch or straw now, and it will keep the ground from freezing. This way, you can easily dig into the ground and harvest them even during the winter. Often these crops will develop more sweetness after exposure to frosty temperatures.
The brassicas — broccoli, cauliflower, cabbage and Brussels sprouts are the big group of above ground crops that also taste better after experiencing frosty temperatures. Unfortunately, it’s too late to plant these crops now — you really needed to plant these in late July or early August at the latest. But make a note to do this next year.
Fortunately, there are some fall crops that don’t need to be planted in midsummer. Fall is a great time to enjoy other cool weather crops like spinach, lettuce, and radishes. These plants don't need much more than about 45 days to produce an edible crop and survive light frost. But it can be tricky to get seeds of these crops to sprout this time of year when evening temperatures are starting to cool the soil.
Once you get these seeds started, these fall vegetable harvests can keep producing into the early winter, maybe longer depending on the outdoor temperature and added protection.
To be successful, you must find a way to capture the heat energy produced by the sun during the day. While we’ve had a lot of comfortable and even somewhat warm days this fall, nights are getting longer, allowing more and more loss of heat energy from the soil. Shorter days mean less time to recoup this energy, and over time the soil cools to a temperature even cool season crops cannot tolerate.
Using a floating row cover or hoop house are ways to counteract this cooling. Both methods involve placing a transparent cover over the crop to capture the sun’s heat, creating a microclimate under the cover around the plants a few degrees higher than the outside air. Sunlight is the only source of heat for these structures.
Floating row covers are relatively small, generally only covering the plants, with or without inner supports to hold the row cover up. They are usually designed to be accessed by opening up or flipping back sections of the cover. Hoop houses are usually much larger, rigid arcs supporting a plastic cover, almost like temporary greenhouses. Hoop houses big enough to stand up in are commonly called high tunnels.
You may want to add a layer of black plastic over the soil to increase the heat retained in your floating row cover or hoop houses. The black plastic heats up and traps the sun’s heat during the day, radiating it to the plants at night. You can use this method in the spring to warm up the soil and get a jump on the season as well.
But what about bringing the garden indoors? It is possible. I have seen people grow crops like lettuce indoors, using supplemental lighting. Lettuce and other greens can tolerate lower light than most vegetables since you're just harvesting the leaves and not trying to get it to flower and set fruit. Flowering and fruiting need a lot more light to be successful.
If your dream is to grow vine-ripened tomatoes indoors, you should plan on building a heated greenhouse with high powered supplemental lighting. But seriously -- starting tomato seeds and growing healthy seedlings indoors can be done with little effort, but growing tomatoes to maturity complete with fruit requires a lot more heat and light than most people can provide in their home. I have seen small hydroponic systems that can grow tomatoes on a kitchen counter, but in my opinion, it's a lot of work for relatively few tomatoes.
While indoor vegetable gardening is pretty limited, there are a lot better candidates for indoor growing in your flower garden. Many annuals can survive and thrive indoors. I’ve had spectacular successes and failures alike bringing annuals inside. But that’s part of the fun. And if it dies, then at least you had a few weeks or months to enjoy it indoors rather than leaving it to die after freezing outside.
Most outdoor annuals will need supplemental lighting to flower indoors, even "shade-loving" plants like impatiens. Shade outdoors in the summer has more light than any sunny window in the winter.
Keep in mind cutting back plants stimulates growth. Without enough light, this growth will be weak and straggly. You may not be able to avoid trimming your plant to bring it indoors, but beyond that, it's usually best to save major cutting back for the spring once the plant can go outdoors again.
You don’t need a special grow light for plants indoors. A simple fluorescent “shop light” fixture only costs around $10-$20. For the bulbs, skip the expensive grow bulbs and use regular fluorescent lights, but use one “warm” bulb and one “cool” bulb in each fixture. Together the wavelengths of light from these different colored bulbs give spectrum adequate for plant growth.
Add in an inexpensive timer to turn your lights on and off, and you’re set. When I had lights, they were on for 16 hours and off for 8 hours each day. Place your lights as close to your plants as possible for best growth.
If you can afford to spend a little more, there are some LED grow lights on the market that take up a lot less space than a fluorescent fixture. I first saw these several years ago, and they were hundreds of dollars per fixture — way out of my price range. Looking today, you can find them for $30 on up. I may need to revisit this idea.
In my own experience, while light is important, proper watering can mean the difference between life and death for plants indoors over the winter. Plants with or without supplemental light will slow down considerably, and will not need nearly as much water as they do in the summer. Too much water just promotes root rot in the winter months. Don’t be afraid to stick your finger in the soil about an inch deep to see that it really is dry before watering.
Whether you extend your gardening outside or bring it indoors, tending to plants in some form or another can go a long way in keeping your spirits up during the dark, dreary winter months.