Getting Your Plants Through a Freeze

by | Dec 22, 2022 | Cold Damage, Freeze protection

We gardeners in the Panhandle have been spoiled by several very mild winters recently.  However, it appears that this pattern will change, at least for a few days, beginning Thursday night.  While forecasts vary depending upon your preferred media outlet, all agree that Calhoun County is going to experience several freezing nights (temperatures in the low 20’s to high teens for hours at a time).  That’s plenty cold to kill many cold-sensitive plants, so here are a few tips to keep your treasured plants alive until warmer conditions arrive next week.

Covering plants to protect from frost, cold snap, blanketing, potted plants, horticulture. UF/IFAS Photo: Sally Lanigan.
  • Bring cold-sensitive potted plants inside.  You can’t dig up your citrus trees and bring them in the living room but bringing cold-sensitive potted plants inside for a couple of nights is a fail-proof freeze protection method.
  • Water outside plants the day before extreme cold hits.  It’s natural, even good, for many tender plants (perennials, bulbs, etc.) to “die” back in cold weather.  This encourages dormancy and reduces pest/disease populations.  However, this week could get cold enough to kill “tops” of sensitive plants AND freeze root systems.  To help prevent this, water the day before a freeze as moist soil loses heat less rapidly than dry. A few degrees can make all the difference!
  • Apply mulch around the base of plants.  Mulch helps insulate the soil and reduces radiant heat losses.  For plants with a graft – like most citrus, pile mulch up around the grafted area.  If the top of the plant dies back, at least it will be able to recover from above the graft (the desirable part of a grafted plant). 
  • Cover citrus and other plants that recover slowly from cold damage.  Draping a non-plastic cloth or blanket mostly helps keep frost off and freezing wind off plants but can also insulate from freezing temperatures if it covers the entire plant to the ground.  It’s better than nothing.
  • Build a “greenhouse” around plants.   You can create a simple greenhouse structure of wooden stakes, pipe, or posts and cover with plastic (making sure the plastic doesn’t touch leaf or stem tissue).  Be sure to get this structure up while the sun is still shining before the freeze event to capture as much solar heat as possible.  For even better results, install a lightbulb, non-LED Christmas lights, or some other heat source inside the plastic structure.
  • Last ditch method – turn on the sprinkler.   Continuouslyrunning a sprinkler over sensitive plants can help protect them.  By running water, you “insulate” the plant to the water’s temperature (above 32 F).  This method requires that the sprinkler begin running before the thermometer drops below 32 degrees and must continue uninterrupted until after the freeze event is over.  If you stop before the freeze is over, the water left on the plant will freeze to whatever temperature the air is, injuring or killing the plant.

We don’t have many freeze events so take a little time this week to bring sensitive plants indoors and implement one or more of the above precautionary measures in your landscape!  Don’t let a few hours of very cold weather set your plants back years!  For more information about cold protection in the lawn and garden, contact your local UF/IFAS County Extension Office.  Stay warm and Merry Christmas!

Daniel J. Leonard
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