When the weather begins to get cooler gardeners know it’s time to think about how to protect plants from frost.
Gardeners know how freezing temperatures and deadly frosts can destroy their precious plants or cripple their crops.
While sometimes it’s necessary to rush outside in the middle of the night to cover delicate and cold-sensitive plants, it always helps to plan ahead in protecting tender plants from cold temperatures and subsequent damage.
Here are some ways to protecting plants from frost, and tips on how to prepare:
If there’s a prediction of frost in the area, you’ll need to take measures for protecting frost-sensitive plants. Do a quick survey and see if you have the following not so hardy plants.
Protect Plants From Frost – Houseplants and Tropicals
- Spring-blooming trees and shrubs such as cherry, rhododendron, and colorful flowering Azaleas
- Tender plants like the succulents, Fuchsia hanging baskets and trees, bougainvilleas, avocados and citrus types.
- Tender bulbs like elephant ear taro and dahlias
- Warm-season annuals such as potted geranium plants, petunia plants, and impatiens
- Warm-season vegetables such as pepper, corn and tomatoes (more on tomato care here)
Cover Your Frost Sensitive Plants
Perhaps the most popular and cost-effective way to protect tropical plants from frost is to cover them with the appropriate material, especially with little or no cloud cover. The covering (different than greenhouse fabrics) serves as a shield against freezing and helps retain much-needed heat plants need to survive.
Remember simply covering tender plants isn’t enough to protect them; you’ll need to make sure the pot plant covers doesn’t touch the foliage or the cold temperature transfers from there. Take off the cover as the morning sun rises to prevent indoor plants from suffocating.
You can either place them near a sunny window where they can get direct sunlight.
The most common coverings are simple household items, burlap sacks, sheets and old blankets. Some use bubble wrap but I would avoid it.
You can also purchase plant covers, frost cloths, frost blankets and garden blankets, each with their own beneficial properties.
Frost cloths are easy to install and allows nourishing sunlight to pass through to plants. These specially made frost protection fabrics do not transmit the freezing air temperature to precious plants, even when they come in contact with the foliage.
How To Apply Coverings Effectively
The best time to cover sensitive plants is before the sun goes down. This ensures the day’s warmth gets trapped under the cover with your plant. Check for any openings that will allow the warm air to escape. Make sure the drape completely covers the plant all the way to the ground. Finally, the frost cloth should touch the ground; more specifically, to the plant’s drip line.
Some additional things you can do for small plants. Get a large cardboard box, cut out the bottom of it. Tape the box flaps shut, then cut the three sides of the top until you form a hinged lid. Place the box over the plant; opened to collect sunlight and warmth during the day, and closed for protection against the frost at night.
For bigger plants, set some stakes in the ground taller in a perimeter of the target plant by several inches. Cover the big plants with the coverings around the stakes, then secure with bricks or rocks.
If you don’t have the time for boxes and stakes, put a patio chair on top of the smaller container plants, then drape the covering over the chair. If your frost-sensitive plants are in container or pots, keep them safe by simply bringing plants in for the winter months or whenever there’s a danger of frost.
The frost cloth should make contact with the ground in order to collect the radiant heat of the day. This rule also applies to trees. Cover only the top of the tree, heat will be lost as soon as the sun sets. Cold air also sinks to the potting soil or potting mix and the fabric won’t be able to cover that part of the tree, making it susceptible to the frost damage.
Watering Your Plants
Did you know you can protect your indoor plants from the cold by watering them?
How? A few days before the arrival of frost water plants thoroughly. Wet soil will collect more heat than dry soil. Water also insulates the plant cells, the soil and prevent desiccation. Don’t water during frost. It result’s in frost heave and accelerates frost damage. The key is to water before the frost sets in to raise humidity and prevent further damage.
Mulching Your Plants
Mulching helps insulate plants from the cold. Not all potted plants can tolerate heavy mulching. For these plant types, a covering will work better.
Popular and common mulching materials include piled-up leaves, bark, pine needles, plastic sheeting and straw. Mulch locks in humidity and heat during the cold weather; for optimal results make mulch about 2 to 3 inches deep.
Cold Frames For Plants
Protective frames, known as cold frames can easily be bought online, at garden centers, or even made at home. Use an old storm window for the top of the cold frame and either brick, wood or cinder blocks for the sides. If you need it in a hurry, you can make use of stacks of hay or baled straw for the sides and put in an old window at the top.
Raised Beds For Plants
Raised gardens beds are effective against frost because of two things – one, cold air stays in sunken areas; and two, the raised soil makes it easier to cover your frost-sensitive plants.
Research your plants to learn any specific needs addressing. Knowing what elements damage them outdoors and taking the steps to prevent damage. Which plants can survive according to your climate zone? Can this tender plant be contained and brought indoors?
Applying fertilizer after frost isn’t recommended, as the new growth flush can be damaged again by freezing weather.
Assessing Your Losses
Even with the best care, frost sometimes gets your outdoor plants. Don’t prune frost-damaged plant parts, nor dig it up immediately. Wait until warm weather arrives and check closely for new growth.
Inspect the plant’s base and trim the damaged parts showing promising signs of life. Remove and replace with hardier plant species if plants don’t survive the frost damage.
Tough shrubs, trees, and tender perennials may still recover from frost even it looks like they didn’t have a chance. The fruits and blooms may be lost for the year, wait until the next growing season arrives, then remove the dead branches and stems accordingly.