Why Extend the Growing Season in South Carolina
Even though most of the Palmetto state has experienced its first frost or freeze, that does not mean that your garden has to be put to bed for the winter.
South Carolina’s mild climate allows gardeners to extend their growing season into early winter with the correct settings. Simple, affordable additions to your existing gardening space will keep your soil and crops warmer, allowing you to continue harvesting throughout the season.
Start small this fall, and you will be surprised by how much you can grow!
Understanding South Carolina’s Fall Climate
Our state is divided into three distinct regions (the Lowcountry, the Midlands, and the Upstate) as well as gardening zones that range from USDA Zone 7b in the cooler, northwestern part of the state to Zone 9b in the warmer, southeastern coastal areas.
Microclimates can affect these predicted dates; for example, raised beds tend to retain heat longer, and urban regions tend to insulate heat more effectively than rural areas.
According to the Old Farmer’s Almanac, using NOAA weather data from 1991-2020:
- USDA Hardiness Zone 9b’s predicted first fall frost is around November 19
- USDA Hardiness Zone 8b’s is around November 9
- USDA Hardiness Zone 7b’s is approximately October 22
Best Crops for Cold-Weather Gardening
Garden setting and crop selection are both key to successful cold-weather growing. Many of these crops can be harvested through December, and sometimes even into early spring with a mild winter, if planted between mid-October and early November, depending on your gardening zone.
Hardier Leafy Greens
- Spinach
- Kale
- Collards
- Mustard greens
- Swiss chard
Cool-Season Herbs
- Chives
- Cilantro
- Parsley
- Dill
- Sage
Root Vegetables
- Radishes
- Turnips
- Beets
- Carrots
A fresh harvest of color kale (Brassica oleracea) from the late fall garden.
Julia Nichols, ©2025 HGIC, Clemson Extension
How to Use Row Covers for Frost Protection
Row covers help to create a mini greenhouse effect by raising the humidity and temperature of the growing area. They are lightweight, permeable fabric sheets typically made from materials such as polypropylene or spun-bonded polyester. Row covers fabrics can vary in thickness for varying applications and temperatures. Hooped row covers, also known as low tunnels, are most effective for cool-season growing compared to other methods.
Tips for Using Row Covers
- Support the fabric row cover with a series of hoops, typically made from wire or PVC to keep the cover suspended above the plants, which provides better protection against cold temperatures, frost, wind, and hail.
- Leave headspace between the hooped row cover and the top of the plants will allow for the greenhouse effect to occur. When row cover directly touches plant leaves, frost can still form, and freezing can still happen.
- Use lightweight covers (0.5 to 1 oz) for frost down to 28 °F, or heavier covers for deeper cold snaps.
A cinder block raised garden bed covered with hooped row cover during the late fall.
Julia Nichols, ©2025 HGIC, Clemson Extension
How to Build and Use Cold Frames for Winter Gardening
Cold frames are an ideal setting for germinating winter greens, growing smaller greens or herbs, or protecting root crops late into the fall or winter. They are, put simply, a warm box with a clear, tilted lid that allows sunlight to penetrate. They can be constructed from repurposed materials, and a thermometer can be added on the inside to monitor humidity levels and temperature.
Building Tips
- Use rot-resistant untreated wood to build the frame base.
- Use an old window, polycarbonate sheets, or glass for a hinged, angled top.
- Add a handle for easy lifting!
- A south-facing spot is ideal for a cold frame because it allows for maximum winter sun exposure.
Maintenance Tips
- On sunny days, the cold frame will need to be ventilated to maintain temperatures below 60 °F.
- Keep the soil within the cold frame moist but not soggy.
- Avoid over-watering, as plant growth will be much slower this time of year.
