Wrap pots in burlap, bubble wrap, old blankets or geotextile blankets. It isn't necessary to wrap the entire plant because it's the roots that need shielding. These protective coverings will help to trap heat and keep it at the root zone.
Bring Plants Indoors
Bringing plants indoors is the easiest way to protect them from frost or freeze damage. Potted tropical and annual containers can be pulled into a heated room, porch, or into a protected and warm structure, such as a garage, to protect them overnight.
Hay/straw is the most common mulch for freeze protection. Some people use large, inverted pots to cover shrubbery, with straw to fill in the empty space. Shredded newspaper will do if you have enough of it.
Trash bags help a lot in case of short (lasting hours, not days) frosts. A single trash bag gives up to +8... +10°F protection compared to the Low. Double bags are ca 50% more effective. In case of longer frosts (couple of days) the effect is +4... +5°F for a single bag and +6... 7°F for double bags.
Most houseplants are native to tropical areas and will not tolerate freezing temperatures. Many indoor plants will see damage when temperatures drop to the mid to lower 40s°F and nearly all will die if exposed to below freezing temperatures.
Covering plant material at temperatures between 39-30 with freeze cloth or covering can be effective. Prolonged exposure at temperatures of 28 degrees and below will notice protection results diminish with each degree dropped.
In general avoid watering plants when temperatures are below 40 F (4 C), unless your goal is to protect the plant from imminent frost injury using water as a protectant.
A light frost may cause minimal damage while a severe frost may kill plants. Young, vulnerable plants are much more susceptible to a light freeze, which occurs when temperatures are 29 to 32 degrees Fahrenheit, while mature plants may only suffer from short-term effects.
Bed sheets or comforters work best for covering large plants and shrubs. Newspaper can be used on low-growing foliage, but it can often be difficult to get it to stay in place. I have used old pillow cases, sheets, towels and even cardboard boxes.
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.
Fabric row cover allows rain in, thus watering your crops. Clear plastic does not allow water penetration. Snow can be tricky with either material… It will build up on the top of fabric row cover causing the material to stretch and droop, potentially putting a lot of weight on top of your plants.
Will a covered porch protect plants from frost? Yes, it will provide partial protection from light ice and chilly winds. Uproot tender perennials — Tender perennials are plants that cannot withstand deep freeze (roots, bulbs, tubers, and corms).
First, as the days shorten and the cold sets in, many plants become “hardened”. Water is pumped out of plant cells into the roots and any remaining sap, which is a sugary solution, often acts as antifreeze. Broadleaf trees, like maples and oaks, shed their thin, flat leaves each fall to reduce water loss.
If using a good covering and the temperatures are expected to remain low, you can keep your plants covered for days.
Lay out your burlap on a flat surface. Place the plant and pot on top of the burlap and position it in the corner so that it is about equally spaced on two sides. Take those two sides and pull them up to ensure they cover the pot itself with at least 8 or 9 inches to spare.
Wrap large pots in hessian sacking or bubble wrap. Tie it securely in place and leave it there throughout winter. If you have large potted plants, wrap the container with a thick layer of insulation, to stop the roots freezing.
You can provide cover to plants by placing potted plants in a garage or shed. Protect landscape plants by using mulch, burlap, sheets, blankets, or – even better – plant freeze protection tarps.
If you're looking for tips for protecting your plants from frost, avoid using garbage bags as plant covers. Trash bags are not the best protection against frost damage, primarily due to their material. Most garbage bags are made out of low-density polyethylene plastic.
Plastic formed into fabric sheets (polypropylene fabric) is an excellent material for frost protection.
A moderate frost, with temperatures ranging from about 28°F to 32°F, necessitates a bit more precaution. In addition to tucking your plants in well with some frost cloth or cover, it's also a good idea to water your plants the evening before frost is expected to hit.
Thoroughly Water plants if it won't rain before the freezing temperatures arrive. It may sound illogical. However, the moist ground stays warmer than dry soil. Watering the night before the freeze will insulate the grass and plants' root structure and decrease the potential for cold injury.
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 root of the trick's protection is a concept called "latent heat of fusion." When the water on the plant starts to freeze, it releases heat (a necessary process to turn water into ice), and that heat helps protect the plant.
It is important to note that some symptoms of frost damage may not appear immediately after exposure to freezing temperatures. In some cases, it may take several days for the symptoms to become visible. Additionally, some plants may be able to recover from mild damage, while others may suffer irreversible damage.
Place cardboard boxes, large trash cans, or plastic tubs over outdoor plants. Be sure to cover the plants all the way to the ground. The warmth from the soil is what keeps the plant warm, since the soil takes longer to freeze.