A fabric covering is best because it will allow moisture to escape while still protecting your plants from frost. Fabric coverings will prevent the freezing air from coming into direct contact with the moisture on the plant while also capturing the heat that is radiating from the ground.
Cover the plants with beds sheets, light drop cloths or blankets, row covers (frost blankets), burlap, cheesecloth, etc. Drape the covering over the plants like an umbrella. Anchor the edges down to capture heat from the soil and hold it around the plants, and to some extent, keep frost from settling on the foliage.
Fabric offers less cold protection, but allows air to flow freely through the fibers. It also allows in water from rain, whereas water runs off of plastic row cover.
Plastic can be used to protect plants from frost, but it's not the best or most effective material. In fact, the horticultural experts here at Green Impressions actually recommend against it. Plastic materials such as vinyl and traditional camping tarps aren't breathable, causing moisture to get trapped inside.
Answer: Either may be used, and each has advantages and disadvantages. A simple cover can significantly reduce cold damage when temperatures are in the mid to upper 20s. Plastic is lightweight and easy to use. If it's rainy, plastic does not get wet and heavy.
One way or another, when a warm spell during winter is forecast to be followed by a cold snap, make sure to protect not only the pot and the roots but also the top of the plant. Cover plants with plastic film, burlap, blankets or other cloth material at night.
When Should You Cover Plants? Cover your plants at night and remove them during the day when the temperatures rise above 32 degrees F, so that the soil can warm up again. Some outdoor plants won't survive the harsh conditions of winter, bring them inside and use these tips for caring for them through winter.
Know Your Plants' Cold Tolerance
Some frost-tender plants need to be covered as soon as the temperature hits 32°F, while others can handle lower temperatures and/or longer freezing periods. You'll need to look up each of your plants to verify its cold tolerance.
The best type of frost protection is frost cloth, which is a breathable fabric because it can 'breathe,' you can leave the frost cloth on your plants for a longer period. But, use it only when there is a threat of frost. After three days, uncover your plants during the day to allow the sun to reach your plants.
It allows about 70% of sunlight to pass through. This isn't enough light for healthy plant growth and therefore should only be used as short-term frost or freeze protection. In mid to late autumn it can be used as winter protection for cold hardy vegetables like spinach, kale, scallions, and carrots.
Frost blankets can be left on all day if lightweight, allow airflow, and allow light transmission. One trick many growers use is to layer fabrics. They will put down a lightweight frost blanket for daytime use and add a heavier duty frost blanket to ensure protection when the temperature dips after sunset.
Properly applied frost cloth can protect your frost sensitive plants from the cold even when the temps dip into the 20s! If necessary, the frost cloth can be left on the plants for an extended period of time without the risk of harming your plants.
If it stays cold for more than one night, can I keep my plants covered, or should I remove the coverings at some point? A. Our recommendation would be to remove the cold protection covering once temperatures are above 32 degrees.
The easiest way to protect from a freeze is simply by covering plants with a sheet or a blanket. This acts like insulation, keeping warm air from the ground around the plant. The added warmth may be enough to keep a plant from freezing during a short cold snap.
Cover Plants – Protect plants from all but the hardest freeze (28°F for five hours) by covering them with sheets, towels, blankets, cardboard or a tarp. You can also invert baskets, coolers or any container with a solid bottom over plants. Cover plants before dark to trap warmer air.
When should I wrap my plants for winter? This Old House landscape contractor Roger Cook suggests to start wrapping your plants in November. If your plants are new, be sure to cover them for the first two years. The older your plants get, the sturdier they become in surviving winters.
I did some research and found out that houseplants need to be taken indoors before overnight temperatures dip below 45 degrees. Most tropical plants suffer harm from temperatures below 40 degrees. Well, we have temperatures forecast to dip into the 40s again on Thursday and lower 40s on Friday.
Hardy plants can be hardened off when the outside temperature is consistently above 40° F. Half-Hardy plants may be hardened off at 45° F.
Some plants can survive outside even when temperatures hit freezing. Others need to be brought indoors when temperatures reach the mid-40s. Be sure you know this before you plant.
Indeed, a plant that is drought stressed will often show more damage after a light freeze. So if they are dry, always be sure to water your potted plants before a freeze to help them better handle the cold.
From that experience, I've found the best frost protection for your outdoor plants is either free or cheap. Cardboard boxes and brown grocery sacks make perfect frost cover and at the end of the season can be recycled. I keep various boxes on the patio and when frost is forecast simply put one over the plant.
A frost blanket is a sheet of fabric, plastic, or other material used to cover plants in cold. There are different types of frost blanket, some designed to protect crops, others designed to shield plants in a home garden.