Freezing temps expected across California and how to protect your plants

UC Master Gardener Program Statewide Blog

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News and updates from the statewide UC Master Gardener Program office.

Author: Melissa G. Womack

Published on: February 23, 2023

California will be hit by an unusually cold storm this weekend, with snow possible at low elevations and a blizzard warning for parts of Southern California. Freezing temperatures can cause serious damage to plants, and it's important to take steps to protect them.

Here are seven tips on how to protect your plants from freezing temperatures in California:

Water your plants. Make sure your plants (not succulents) are hydrated before a freeze. Water the soil around the base of the plant, this will help to insulate the plant and keep it from freezing.
Cover your plants. Use blankets, fitted bed sheets, or frost cloths to cover your vulnerable plants. Make sure the cover reaches all the way to the ground and is securely fastened to prevent cold air from seeping in. Do not use plastic covers, as they can trap moisture and damage the plant. Make sure to remove the covering when the temperature rises.
Add warmth for your plants. Use incandescent miniature lights (not the LED type) to provide warmth and raise the temperature around your plants. Position a 100–150 watt light in the center of the tree and cover the plant with a sheet.
Bring potted plants indoors. If you have potted plants, move them to a sheltered area (ie. Porch, indoors, under an awning), when temperatures are expected to drop. If possible, cluster potted plants close together in a sheltered spot close to the house. If plants are brought indoors, place them near a window that gets sunlight.
Mulch your plants. Apply a layer of mulch around the base of your plants. This will help to insulate the roots and keep the soil warm.
Prune your plants. Prune any dead or damaged branches from your plants before a freeze. This will help to prevent further damage from occurring.
Monitor the weather. Stay up-to-date on the latest weather forecasts and take action if freezing temperatures are expected. If possible, move your plants to a warmer location or cover them before the freeze sets in.

It's important to note that different plants have different levels of cold tolerance. Some plants are more susceptible to freezing temperatures than others. If you're unsure about how to protect a particular plant, consult with your local UC Master Gardener Program for advice, mg.ucanr.edu/FindUs.

By taking these steps to protect your plants from freezing temperatures, you can help ensure that they stay healthy and vibrant year-round. With a little extra care, you can keep your garden looking beautiful no matter what the weather brings. Stay warm this week!

Additional Resources:

Frost Protection for Citrus and other Subtropicals (UC ANR publication 8100)
https://anrcatalog.ucanr.edu/pdf/8100.pdf

UC Master Gardener Program of Marin County, Problems, Extreme Conditions – Frost
https://marinmg.ucanr.edu/PROBLEMS/EXTREME_CONDITIONS/Frost_853/

"Frozen Plant" by mrrobertwade (wadey) is licensed under CC BY-NC-SA 2.0.

Focus Area Tags: Yard & Garden

Comments: 5

Comments:

by Kitty Rozenstraten

on February 24, 2023 at 7:34 AM

Yes, please keep me up to date.

by Allen Buchinski

on February 24, 2023 at 8:32 AM

A timely post! We’ve always advised people to NOT prune before freezing weather, because the material may provide a little extra protection from the cold. If plants do have frost damage, it’s a good to wait to prune until after the chance of cold weather; the damaged material can provide insulation, pruning might stimulate tender (susceptible to more damage) new growth, and you can see where new shoots form, so you don’t prune something that looks dead but might not be.

Reply by Melissa G. Womack

on February 27, 2023 at 11:01 AM

Pruning out dead or damaged parts prevents breakage when plants are weighed down by ice. This pruning is different from aesthetic pruning which we agree should not happen before a freeze.

by Debbie Rice

on February 24, 2023 at 10:24 AM

Thanks Melissa for this informative article. I look forward to serving with you post "graduation".

Deb Rice
MG Class of 2023

by Yvonne Savio

on February 24, 2023 at 12:42 PM

Your number 6, suggesting pruning, will open up the plants to immediate danger of frost. Leaving the dead branches will deflect the immediate flow of frost onto those branches before entering the plant further to actually damage viable foliage. We learned this with that tremendous freeze we had years ago. Better to leave dead and damaged foliage on the plant - however unkempt - until new growth appears.