Home Improvement Expert Danny Lipford

How to Protect Your Garden from Frost and Freeze

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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.


Fragile blossoms are threatened by late spring freezes.

Effects of Freezing Temperatures on Plants

For all but the most tender plants, it doesn’t matter whether the conditions produced a frost or a freeze. What’s important is how cold it got and for how long. When temperatures near freezing, a few degrees can make a big difference. To advise gardeners, so they can take proper precautions, different terms are used to describe the severity of a freeze. The chart below explains the various terms that are used:

Temperature Type Effect on Plants
Down to 28° F for a couple of hours Light Frost,
Light Freeze
Usually only harms very tender plants. Ice forms only on the outside of the plant.
25-28° F for several hours Hard Frost,
Killing Frost,
Moderate Freeze
Damages foliage and blossoms. Ice forms inside the plant, causing plant cells to burst. Will kill back root-hardy perennials and damage crops.
Below 25° F for several hours Severe freeze Causes damage to many plants, mostly through desiccation (drying).

The average first and last frost dates for a given area usually refer to the occurrence of killing frosts. These are most often caused by fronts of arctic air moving in and are more indicative of seasonal change. Research has shown that most crops and plants can recover from brief dips below freezing, but when the temperature reaches 28° F it begins to cause extensive cellular damage and crop loss.


Avoid stimulating tender growth with fertilizer until freezing weather has passed.

How to Protect Tender Plants from Frost or Freeze Damage

If frost is predicted in your area, you may want to take steps to protect vulnerable plants such as:

  • Houseplants and tropicals.
  • Spring-blooming shrubs and trees such as azalea, rhododendron, and cherry.
  • Citrus trees.
  • Tender bulbs such as dahlia and elephant ear.
  • Warm-season vegetables such as tomato, corn, and pepper.
  • Warm-season annuals such as impatiens, petunia, and geranium.


Shrubs can be covered with a blanket to protect them from a late spring frost.

Steps to take when frost or freeze threaten tender plants:

  • Protect Tender Sprouts: Cover tender plants overnight with an inverted bucket or flower pot, or with a layer of mulch. Be sure to uncover them in the morning when the temperature rises above freezing.
  • Cover Shrubs and Trees: Larger plants can be covered with fabric, old bed sheets, burlap, or commercial frost cloths (avoid using plastic). For best results, drape the cover over a frame to keep it from touching the foliage. Fabric covers help to trap heat from the soil, so make sure your cover drapes to the ground. Uncover them in the morning when the temperature rises above freezing.
  • Assess Losses: Hardy perennials, trees, and shrubs may recover from a late spring freeze, even if visibly damaged. Their blooms and fruit may be lost for the year, but once they begin actively growing you’ll be able to determine and remove any permanent damage to stems and branches. Frost-tender plants will not recover at all, so avoid planting them until you’re confident that freezing weather has passed.
  • Practice Prevention: Choose plants that are hardy for your climate zone, or plant tender plants in containers that can be brought indoors. Avoid applying fertilizer until after the last frost, to prevent a flush of tender growth that can be damaged by the cold.


Though blooms may be lost, hardy plants can recover from a freeze.

Further Information

To find the average frost dates for your area, check out:

Also check out:



Please Leave a Comment

19 Comments on “How to Protect Your Garden from Frost and Freeze”

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  1. Jeff Says:
    October 10th, 2010 at 11:06 am

    Well done article. Watering your plants the night before is an interesting idea that I’ll have to try out.

    Jeff

  2. Jacqueline Ruhl Says:
    March 27th, 2012 at 1:25 pm

    Can you tell me why my Spiny Bear’s Breeches didn’t bloom all last summer? What would cause this?

  3. elaine noerper Says:
    March 29th, 2012 at 8:52 am

    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.

  4. Colleen Reske Says:
    April 6th, 2012 at 8:24 am

    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.

  5. Charlotte Stubbs Says:
    October 9th, 2012 at 4:13 pm

    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.

  6. Ann Says:
    January 2nd, 2013 at 6:12 pm

    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??

  7. Regina Says:
    January 6th, 2013 at 8:06 pm

    Goodenough I plased a sheet over my flowers…I was counting on that being enough. Signing Out Sincerely Regina

  8. Larry Says:
    January 10th, 2013 at 11:25 pm

    Getting ready to do battle with the freezing temps tomorrow night. Going to follow the suggestions.

  9. Julia Says:
    January 19th, 2013 at 5:16 am

    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.

  10. Official Comment:

    Ben Erickson Says:
    January 19th, 2013 at 7:33 am

    Hi Julia,
    Glad to hear you found our site and Julie’s article helpful.
    Thanks for the feedback!

  11. Vicki Says:
    September 16th, 2013 at 9:48 am

    I have hydrangeas that have not bloomed. They have been planted for a couple years and still no blossoms.

  12. Fred Noble Says:
    October 13th, 2013 at 10:00 am

    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

  13. Dennis Says:
    October 14th, 2013 at 1:23 am

    Can Pine oil be sprayed on cedars in the fall as a anti desiccant .one drop in a gallon sprayed on the shrub thanks

  14. pilar Says:
    December 17th, 2013 at 12:38 am

    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.

  15. Lynda Says:
    February 1st, 2014 at 1:52 pm

    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.

  16. joymc Says:
    February 27th, 2014 at 1:26 pm

    Can flowering bulbs I planted stand 34 degrees and many have already popped up?

  17. Katie Says:
    March 5th, 2014 at 1:14 pm

    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.

  18. Jill Says:
    March 11th, 2014 at 4:20 pm

    Going down to 0 with the windchill- 14 degrees. Will covering plants even help?

  19. lynda w Says:
    March 11th, 2014 at 5:17 pm

    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.

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