How to Protect Your Garden from Frost and Freeze

Frost on green leaves
Crystals of hoarfrost sparkling on green foliage

One of the biggest worries of gardeners is the threat of freezing weather and frosts that can harm or kill plants and damage crops. Here’s what you need to know to protect tender plants from freezing temperatures.

What Is a Freeze?

A freeze occurs when temperatures drop below the freezing point of water (32° F or 0° C). When the water inside a plant freezes, it can cause the plant cells to burst, resulting in irreparable damage.

Plants react differently to freezing temperatures:

  • Tropical and frost-tender plants: Cannot survive freezing temperatures so they only grow naturally in warmer climates.
  • Annual plants: Can’t survive a freeze, but they disperse seeds to replenish their numbers once the weather warms.
  • Root-hardy perennials: The foliage is killed back by a freeze, but the roots survive in a dormant state until spring.
  • Fully hardy perennials, shrubs, and trees: Enter a dormant state, which decreases vulnerability to freezing temperatures by reducing sap content and conserving water. Spring blooms and early foliage may be damaged by late-spring freezes, but the plants themselves usually recover.

What Is Frost?

Frost occurs on clear, still nights. As the air temperature approaches freezing, the surface temperature of plants can dip below freezing, causing ice crystals to form in the same manner that dew forms on warmer nights. Because temperatures vary just a few feet above the ground, frost can form when your thermometer reads above freezing. Freezing temperatures may or may not be accompanied by frost.

Types of frost include:

  • Hoarfrost is the familiar feathery white frost you see on chilly mornings. It results when water in the air is deposited directly in the form of ice crystals.
  • Rime happens when water is deposited in liquid form through dew or fog which then freezes. Rime has a glazed appearance.
  • Black frost is a term used when frost didn’t form, but plants were nonetheless damaged (and blackened) by freezing temperatures.

38 COMMENTS

  1. We planted two weeks ago, fertilizer mixed in soil because the soil had been struck by lightning and was not producing. Also, mixed new top soil and potting soil in rows. We have shoots and live plants, fruit trees and fruit shrubs were planted aswell. A cold front is predicted for here (childersburg, alabama) around easter. How can we protect so many? Should we spray heavy the day before? Help.

  2. Excellent article on various types of frost and methods of frost protection. The temperature differentiation between light and hard frost was most helpful, as was understanding how the frost moves within the plants. Thank you.

  3. We bought lots of used sheets to put over our garden when it freezes. Works like a charm. And cheaper then the “blankets” they sell for a small fortune.

  4. Great info.. I live in Fl. and have a veggy garden right now I usualy put sheets over my veggies. It seems to keep them alive 🙂 I wrote to you a few months ago about my oak tree and all the baby (seedlings) that are sprouting all around it. It made it on your radio show . I was told to pull them out..That did not work. They are very deep roots. Any other way to get them out??

  5. I am a first time visitor to this site, and I find the information almost limitless. just scanning through the projects I have also found there to be so many helpful ideas and how-to’s. The information helps one to be self-suffienent and independent. The how-to’s helps one avoid many costly mistakes of the past.

  6. Is there a Product that you can spray on outside plants during the winter season that would protect from Freezing..for potted plants not huge plants..prefer not to use sheets or blankets! Thank You..See a lot of info on internet but where to purchase? Thanks Fred Noble Portland Or 97225

  7. I am moving in december from Quebec to Ontario. It will be freezing. What should I do to protect my plants, they will be for two days on the truck?
    Thanks.

  8. I have bamboo with loads of small branches. I cut these off, put each end in the ground over tender plants and the cover these hoops with sheets and sometimes even add a sheet of plastic over the sheet to protect plants for wind. Seems to work really well. I sometimes also
    add a string of mini christmas lights, not led as they produce no heat, and this also helps to keep tropicals from freezing.

  9. I have perrenials planted on two terraces that have survived 8 winters, even when covered with snow plow pile up. This year in Wisconsin we have had one deep freeze after another. Covering my terrace gardens now is @ 6 ft. of solid ice and the ground is frozen deep down. Flooding is expected. Will my perrenials/bulbs survive? Thank you.

  10. It will help, but not with just a light covering. It will also depend on the types of plants. First, make sure they are well watered. Next if you have any christmas lights that are NOT led, plug those in and string around the plants, next add a few supports to hold coverings. Anything that you can push into the ground or pot at about 12″ intervals. Now first cover with sheets, old blankets, or other pieces of fabric. Make sure it is long enough to drop to the ground. Now put a piece of visqueen or plastic drop cloth over that and place something heavy on all of this to keep the wind from blowing it of. This is where the supports will be crucial. Hopefully this will work. Water is vitually important to keep the roots from freezing. The lights, whether christmas or any other non-Led will help and securing the covering to the ground will prevent wind burn. Good luck, it sounds tedious but just gather everything and go for it.

  11. We have a tall (approximately 13 ft) Rubber tree plant. We raised it from a cutting, so it’s our baby!!! We live (don’t laugh) in Southern CA. no wait listen, it’s supposed to freeze for the nest couple of nites…So pleeeeze tell us HOW TO PROTECT IT???
    Helpless in So CA.

  12. a week or so after i planted vegetable seeds in a raised garden bed, we got several nights of below freezing temps. If nothing has sprouted above the surface, will the frost effect the newly planted seeds?

  13. In answer to non sprouting vegetable seeds being damaged by frost. I live in zone 3b. No problem if the seeds have not sprouted. I put my seeds in on May 14th and had frost last night, May 17th. May get frost again before June. The seeds will germinate when the soil temperature is around 20 degrees C. Have tomato plants in the back window for now and will put them out first week in June to be safe.

  14. we just moved from Tennessee to Florida and there is a hydrangea planted in front of the house that gets full mid to late day sun. Most of the upper leaves are burned and it hasn’t bloomed since we moved in July 1. Should I move this plant or build a shield for it for protection from the hot florida sun? I keep it watered and it looks healthy other than the sun burned leaves

  15. I have some rare plants, which will not survive the cold temperature here in SC, I have planted them in the planter on my patio, can I protect them from frost by covering them with bedsheets, should I double layer the sheet? Do I have to uncover my plants time to time during cold weather? Also can I put them in my garage, they will get minimum sunlight though? Once I brought them inside the house and there were eggs laid by lizard and they hatched in the warmth of the house and I had huge problem later with those pesky little creatures. Pl. advise the best option for my plants

  16. I live in Victoria Australia
    thank you so much for the information on frost for my new plants it is very helpful
    kindest regards Judy

  17. What about potted annuals that can’t be brought inside?
    Can they be covered …
    . . . and left on a concrete patio?
    . . . and left on a wooden deck?
    . . .and placed on the lawn?
    Which of those options is the best?
    Is it advantageous to put them adjacent to the house? And if so, how does that factor in? For example, is on a concrete patio placed adjacent to the house likely be better than placed on the lawn away from the house?
    Thanks!

  18. Cardboard boxes are excellent for protecting plants. Just wrap the cardboard around the plant to block the wind and secure it with binder clips or sturdy tape. Cover with blanket or sheet.

  19. 1. I gave the plants on the porch front porch water yesterday because they need it. One of them is drooping I noticed it before I gave them water I’m not sure if it is the cold weather that got to it or not. The reason I had didn’t cover it was is because I don’t know what kind of planet is and if it can survive the cold or not. What can I do to get it to pyrkup? It has in the 30s here in North Carolina. 2 of the plants came from the funeral home in Louisiana.

  20. My Peach tree did not produce any peaches last year it may have gotten frozen. One thing that continues to grow is a green fungus. I sprayed but no luck I pick some of it off but it grows bigger. How can I get rid of the fungus?

  21. Hello
    Every year, due to climate change and snow, we lose our hazelnut products in the spring and unfortunately no solutions have been presented so far. Please advise if you have any suggestions. Karimi . Iran

LEAVE A REPLY

Please enter your comment!
Please enter your name here