Guide to Protecting Your Fall Garden from Frost and Snow
Photo taken December 27, 2020
As temperatures drop and winter nears, protecting your fall garden from frost and snow becomes essential. Cold temperatures can damage or kill plants if they’re not properly protected. This guide offers fall garden weather protection tips to keep your plants healthy until harvest.
Most fall crops tolerate mild frosts but hard frosts, freezes, and snow can result in significant damage. When low temperatures freeze plant cells they rupture, leading to tissue damage and potentially killing the plant. Frost protection is important for delicate crops like lettuce, which can turn mushy and inedible when exposed to cold.
Plant Protection Quick Tips
Avoid Direct Contact with Cover Materials
When covering plants, never let the plastic material touch the leaves. Frost can transfer from the plastic to the plant, causing it to freeze. Once a leaf freezes, it dies, making crops like lettuce or spinach unusable. Use structures or support systems to keep plastic covers elevated off the plants.
Use Thicker Materials for Heavy Frost or Snow
As the weather gets colder, thicker materials are needed to protect your plants from the elements. This can include blankets or layered fabrics. In areas prone to snowfall, the weight of snow can break plant stems and branches. Adding structural support may be needed to prevent snow from weighing down and crushing your plants.
Cloches: Small-Scale Frost Protection
A cloche is a small, dome-shaped cover that provides good frost protection for individual plants. Traditional cloches were made of glass, but today’s options include plastic and even water-filled walls that insulate plants. You can also make a simple DIY cloche by placing a 5-gallon bucket over your plants. For extra protection against cold and snow, lay a blanket on top.
Pictured: Spring plants protected from late snow.
Row Covers: Lightweight and Effective
Row covers are a great option for protecting rows of plants from frost and are laid right on top of the plants. These covers are typically made from lightweight fabric, which allows air and moisture to pass through while protecting plants from the cold. There are different weights of row covers available, depending on how much protection you need.
When choosing row covers:
Use breathable fabric to avoid trapping moisture and heat.
Avoid plastic, as it doesn’t allow air circulation and can damage plants.
You can use household items like sheets and blankets in a pinch, but they’re heavier and less breathable than garden fabric. They may also collapse under rain or snow.
Hoop Tunnels: Elevating Plant Protection
Hoop tunnels offer a more robust solution for protecting larger areas of the garden. By using a framework made of sturdy wire, PVC, or electrical conduit, you can elevate a protective cover over your plants. This prevents the cover from touching and potentially damaging delicate leaves while creating a mini greenhouse to trap heat.
There are two types of hoop tunnels:
Low tunnels protect smaller plants and use single or double layers of covering. These are the most common for the home gardener.
High tunnels are taller versions of low tunnels, large enough to walk through. They can be fitted with supplemental heating for colder climates. These are often used for commercial purposes.
Low tunnel frame left in place for the summer.
How to Build a Low Hoop Tunnel:
Set hoops at 3-foot intervals along your garden bed. (I used 8-foot long, 1/2-inch PVC for a 4-foot wide garden bed, and pushed each PVC end into the soil.) A length of PVC can be zip-tied to the top across the hoops for extra stability and to prevent collapse with snow.
Stretch fabric or plastic tightly over the hoops and fasten with clips.
Secure the cover at the base to prevent it from collapsing or being blown away by the wind.
Vent the tunnel during warmer periods to avoid overheating.
Cold Frames: DIY Garden Shelters
A cold frame is a simple but effective way to protect plants during the fall and early winter. It’s essentially a wooden box with a clear top (glass or plastic) that acts like a small greenhouse. The sides of the cold frame provide insulation while the clear top allows sunlight in.
For best results:
Use a cold frame for hardy crops like kale, spinach, and carrots.
Open the top to vent excess heat during sunny days to prevent plants from overheating.
Greenhouses: Long-Term Garden Protection
If you’re looking for a more permanent solution, a heated greenhouse is your best bet for year-round gardening. A heated greenhouse can provide optimal protection from frost, snow, and cold temperatures while allowing you to grow plants in a controlled environment.
Key features of greenhouses:
Permanent structures with glass or polycarbonate windows.
Great for extending the growing season.
Use power for ventilation and supplemental heating when necessary.
While a greenhouse is an investment, it offers the highest level of protection for fall and winter gardening.
Sadly, my greenhouse (pictured here) is unheated. However, I can use it for season extension, similar to low tunnels.
Fall garden weather protection is a good way to keep your plants alive and in good condition until harvest. Whether you’re using cloches, row covers, hoop tunnels, or a greenhouse, the goal is to protect plants from frost, snow, and cold temperatures while allowing them to receive sunlight, air, and moisture. By using the right methods and materials, you can ensure a successful fall gardening season.