COVER plants before nightfall
Covers don’t have to be elaborate or expensive in order to work. A row of sticks with newspaper, cardboard or sheets and towels tented over them will do just fine.
If you don’t have sticks, lay the covers directly over your plants. This too will prevent heat loss.
If you’re going to cover up your plants before a hard frost, do so before dusk. If you wait until darkness falls, most of the stored heat in your garden will have dissipated.
No matter what type of cover you use, make sure that it extends down to the soil on each side. In the morning, after the frost has thawed, remove the covers.
Warm plants with water jugs
Fill plastic milk jugs with water and place them in the sun, allowing them to soak up heat during the day. Before dusk, set the jugs around your plants and throw a cover over them. The water in the jugs will lose heat more slowly than the soil and the air and the warmth it emits will keep your plants warm.
Water before a frost
It may sound crazy, but watering around plants the night before a spring frost can protect them from freezing. During the night, the wet soil will release moisture into the air, which will raise the temperature and keep plants warmer.
Cover plants with cloches
Strictly speaking, cloches are removable glass or plastic covers that protect plants from cold. Sometimes called bells or bell jars, most fit over individual plants, but some are large enough to cover a row.
Glass cloches are highly ornamental. When you’re not using them outside for frost protection, you can use them indoors over humidity-loving houseplants like violets.
Plastic cloches are generally less expensive than glass ones. Because they are lightweight, they must be staked into the ground to prevent them from blowing away in high winds.
Like other covers, cloches should be placed over plants before the sun goes down and removed in the morning after the frost has thawed.
Place plants in frost-resistant spots
It’s as true for plants as it is for property: location, location, location. Set out seedlings and store-bought spring plants in areas that are less likely to experience damaging cold.
As cold air moves to lower ground, it will pass by plants located on high ground or slopes. That’s why it’s best to place seedlings and other plants that are susceptible to frost in these locations. Shrubbery also provides protection from light frosts.
Placing plants by walls and fences can provide additional protection, particularly if the structures are dark in colour. During the day, the structures absorb heat. Throughout the night, they radiate it, keeping plants warmer than they’d otherwise be.
Avoid frost pockets
Frost pockets are depressions in the ground. Cold air drains into these “pockets,” and it can’t get out. When this happens, plants located in the depressed areas can suffer frost damage. Avoid sowing seeds and bedding new plants in these low places.
Harden off seedlings
Before setting out seedlings, acclimate them to the outdoors by gradually exposing them to conditions outside. This process, called hardening off, will help you grow stronger plants that are more likely to withstand the vicissitudes of early spring.
Begin the hardening off process about 14 days before transplanting. When the weather’s mild, place the seedlings outside during the day in a warm, shady spot that’s protected from the wind. At night, bring them indoors.
After two weeks, the seedlings will be stronger, sturdier plants, ready for transplanting.
Protect potted plants
When frost is predicted, bring planters and hanging baskets inside.
The roots of potted plants experience more severe temperature fluctuations than those planted in the ground. They’ll reach lower temperatures, too. That’s why potted plants are especially susceptible to root damage due to cold. It can cause their roots, particularly those near the edge of the pot, to turn spongy and black. Although root damage may not kill the plant, it will stunt its growth.
If you opt to cover a hanging basket rather than bring it inside, place it on the ground first, and then place the cover over it in order to take advantage of the ground’s relative warmth.
Wrap fruit trees
If you grow fruit trees, be sure to wrap the trunks in the fall with burlap strips or tree wrap. Most fruit trees have thin barks that are susceptible to splitting when temperatures fluctuate dramatically. Tree wrap will prevent this splitting, which is known as frost crack.