How to Protect Your Plants From the Next Frost
Spring is on the way, but North Carolina’s weather is notoriously unpredictable. Even on warm, sunny days, early-spring temperatures can drop below freezing at night. Protect your plants from the next frost with these tips and tricks.
What is a Frost?
A frost is a thin layer of ice that covers the surface of the ground when temperatures are between 32 degrees and 36 degrees Fahrenheit. Frost advisories or warnings are issued by the National Weather Service to alert local areas of oncoming cold temperatures. Frost (and freeze) warnings are issued during the growing season, which includes the spring and fall.
When Can You Expect Frosts to Occur?
Depending on where you live in the United States, frosts happen during various months of the year. North Carolina ranges from zones 5b to 8b, respectively. Within the Triangle, you can expect frosts to happen in late November, up until mid to late April. Frost advisories aren’t issued during the winter months when plants are dormant.
While the weather is warming up, consider waiting a few weeks to get outside in your garden. Planting too early puts your garden at risk for frost damage.
Frost Protection Strategies for Outdoor Plants
Soft-tissued plants are especially prone to frost damage. While some plants are more resilient than others, frost-damaged plants may take a few growing seasons to fully recover. To protect your outdoor plants, consider a combination of these strategies.
Move Potted Plants Indoors
For potted plants, it’s best to move them indoors the night before an expected frost. Typically, your local weather station will issue an advisory the night before or a few days preceding an expected frost. This gives you plenty of time to move your plants indoors into a warmer, safer environment.
Cover Plants with Blankets
Covering your plants before it gets dark traps warmer air and creates a barrier from the frigid air. Protect your garden beds by placing towels, blankets and even sheets over them. For smaller areas, hard-bottomed items (like coolers or containers) can be utilized as well.
Traditionally made from glass, garden cloches are bell-shaped and protect your plants from cold temperatures, gusty winds and pests. Garden cloches typically only cover one plant, so it’s important to prepare beforehand to ensure each plant is protected.
Add a Layer of Fresh Mulch
Mulching your garden beds with the right blend of materials helps to maintain the soil’s temperature before a frost. Choose materials that absorb excess moisture like pine needles, straw and wood chips to prevent frost from forming.
Move Plants Into Cold Frames
Cold frames are wooden boxes built with an open bottom and hinged, clear lid. The sun’s rays are able to enter the structure and provide warmth—just like a greenhouse. You can build DIY cold frames, as long as the plant is enclosed with four walls and a clear top.
Water Plants in the Morning
The morning before a frost, thoroughly water your plants if rain isn’t expected. Although it sounds counterproductive, watering your plants insulates their roots and the ground surrounding them. Moist soil stays warmer than dry soil, so give your plants a much-needed soak before the temperature drops.
What Should You Do After a Frost?
After a frost, inspect your plants for frost damage. If there are any visible brown or wilted areas, don’t prune them just yet. If frost-like conditions are supposed to continue for a few days, pruning damaged plants may do more harm than good. Wait a few days and reassess frost-damaged plants before pruning, fertilizing or removing them.