Saving the Garden
During Freezing Temperatures

By BJ Jarvis

County Extension Director & Horticulture Agent for
Pasco County Cooperative Extension Service

small sago palm shown before coverage and after coverage for cold protection

With the temperatures expected to dip below the freezing mark tonight in central Florida, there are a number of steps gardeners can take to help preserve tender plants.

So choose wisely how many plants really need gardener intervention to survive winter’s chill. Many plants don’t need protection or will experience only cosmetic damage, reviving once the weather improves in a few weeks.  Others may die to the ground but have roots protected by the soil.  Save effort by determining what really needs protecting.

How many times have we seen a plant canopy bundled up in a sheet?  This provides little protection for the “heart” of the plant – at its roots.  If you are going to try to protect a plant, protect it all the way to the ground where it will benefit from the radiant heating coming from the earth.
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Don’t use plastic―Plastic in direct contact with leaves can actually intensify the effects of cold, causing leaves to “burn”.  In addition, you must remove it early before the sun cooks plants underneath.  Most of us don’t have the luxury or inclination of getting out and removing the plastic covers at “just the right time.” 

There are a number of specially spun polyester fabrics for this purpose (called floating row covers) which is lightweight and heat-retentive, but other materials are potentially more abundant and cheaper to use. Bed sheets, blankets, table cloths, or even an overturned garbage can will all do the job well.

While you may see growers using water to protect strawberries and citrus, leave this practice to the professionals and don’t water!  First they have special equipment which is less likely to freeze, but to assure proper functioning growers stay up all night monitoring.  Most of us want to be snug under the bedcovers when the temps dip below the freezing mark, so save time and WATER and potentially your irrigation system by not watering.
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Cover plant roots―Start with non-manmade mulch, such as wood chips.  Mulch not only keeps the soil warmer during cold snaps, but also reduces weed competition and retains moisture. 

Another way to protect plants is to lay limbs (maybe from Christmas tree) over the plant and its roots.  The limbs provide additional wind protection.

Cover early―You are trying to retain the heat from the ground, so cover plants early in the day before the wind blows the warmth away.

Plants in containers don’t have the same insulation value as soil-grown plants but benefit from being mobile (some more mobile than others). Since the soil around the container-grown roots may freeze, move pots into the garage, up against the house, or in a group together for added protection.

Last, after the cold temperatures, don’t be in a big hurry to prune any damage.  Pruning actually sends a message to the plant to put on new growth.  In central Florida we can get cold weather through the month of February.  The dead wood may provide additional protection for the next cold snap.

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Strawberry Plant Emerging from Mulch