Mild fall and winter seasons in Central Texas provide me year-round opportunities to grow a variety of food crops — with the occasional need for special cold and wind protection. Not everyone is so lucky. Yet, winter doesn't have to be a food gardening wasteland if you live in northern planting zones; growing and harvesting food crops all year long can be a reality with planning and a little know-how.
The Right Crops for the Conditions
Unless you have a well-heated greenhouse, don't expect success from food crops like tomatoes, eggplant and summer squash during frigid months. However, if you're willing to cultivate hardier crops like broccoli, carrots, spinach and beets — and provide the proper environment for them — you can harvest and enjoy fresh food all winter long.
Garden in a Box
For gardeners who live in plant hardiness zones where winter temperatures seldom dip below zero, think: cold frame. A cold frame is a bottomless wooden box placed over a planting bed to protect seedlings and plants without the addition of artificial heat. These simple boxes create a microclimate several degrees warmer inside than the outside ambient air.Cold frames have clear glass or plastic tops that can be propped open for ventilation (when needed). Some folks like to build, or buy, cold frames that are angled to capture more light from the winter sun. Build them large enough and you can place jugs of water inside the frames. These jugs absorb heat during the day and release it at night. If you have more clouds than sun during fall and winter, paint the inside of the frame white to reflect more light onto your plants. Doing these things can mean the difference between a fresh green winter salad and frozen green sludge.
Layering works to keep us comfortable in cold weather, and it works for plants as well. Whether you plant at soil level or in a raised bed, a double-covered low tunnel system can keep your crops comfy even when it's cold and snowy outside.
Take flexible ½-inch PVC pipe or ½-inch metal conduit, and arch it over a bed that’s been planted. Ideally, keep beds 30 inches wide for best stability of the arches. Arch the pipe (bend it in the case of the conduit) every three to five feet over the planting bed, and then sink each end 10 to 12 inches into the ground to secure them, creating the frame for a low tunnel.
Drape a polyester row cover over the arches (width depends on your planting bed); weigh down the fabric with bricks or bags of gravel. Excess fabric at the openings of the tunnel can be bunched up, tied with cord and tied securely to a stake pounded into the ground. Make sure the cord is taught, as this will aid in the stability of the tunnel. Access the bed by raising the row cover.
Before the first big cold snap or snow, cover the tunnel with thick greenhouse plastic, securing it like you did the fabric. The plastic keeps winter wind and snow from playing foul with your crops. The temperature under the layers is conducive to growing a variety of hardy crops. If you get a winter warm spell, lift the plastic to provide a bit of ventilation.
Just because there might be snow on the ground, you can still enjoy growing food in your own garden.
Do you have any fall and winter food gardening tips to share? I'd love to hear your ideas!