UF/IFAS Okeechobee County Extension Service

458 Highway 98 North

Okeechobee, FL 34972-2578

Phone: (863) 763-6469

E- mail:  dfculbert@ifas.ufl.edu

Re-issued:   January 4, 2010

Feature Article - originally released February 27, 2007

Dan Culbert - Extension Horticulture Agent

 

 Dealing with Frost Damage

Some local residents have just returned from brief holiday visits up north, and had a chance to experience first-hand the snow, ice and all the gloomy challenges that send winter visitors back to the Sunshine State.  While they were gone, Jack Frost paid a visit to our area, and judging from the phone calls this past week, some local plants have paid a price to winter weather.

Dealing with cold temperature damage to plants in your Florida Yard involves patience.  Today’s column will give readers some ideas on what can be done to help frost damaged plants recover from the jaws of old man winter.

 

One call in particular asked what can be done to get the lawn quickly green again.  Advice from UF specialists offers many ideas on how to prepare a lawn or landscape to handle cold temperatures.  Dealing with damage is different.  The best course of action for turf and other ornamental plant recovery is to wait for warmer conditions to return, and then resume normal but not excessive amounts of water and fertilizer. 

Water Needs

Plant water needs should be checked after a freeze.  The leaves will continue to release water vapor (transpiring), especially on those clear sunny days after a freeze.  However, if water in the soil or a container is frozen, it will not be able to move up into the plant.  Wilted plants will be the result.

In the short term, applying water to the soil will help thaw it out and provide available water for the plant.  Water may actually serve to warm the roots and get them to work better.  Be certain not to add too much water - overwatering can reduce the amount of air space in the soil and can encourage soil borne root diseases.

Sometimes the soil in container grown plants will have a white crusty deposit on the surface.  This may indicate a buildup of salts from over-fertilization or hard water deposits.   If the soil or media has high amounts of  soluble salts, it definitely should not be allowed to dry out.  This is  because salts would be concentrated into a smaller volume of water, and can cause “fertilizer burn” on plants. 

Pruning

Severe pruning should be delayed until new growth appears.  However, dead, unsightly leaves may be removed as soon as they turn brown.  If possible, wait until they naturally fall if the appearance factor is not critical.

Before the pruner touches the plant, be sure that the place where the cut is to be made will be in live wood.  Do not remove living plant parts that contain stored up food reserves.  Remember that pruning scars will only heal if the cuts are made into living tissue. 

Cold injury may appear as a lack of spring bud break on a portion or on all of the plant.  Some may show an overall weak appearance.  The outer branch tips may be damaged,  while older wood can be free of injury.  

The “line” between dead and live wood will eventually be “marked” by the growth of a new bud.   If you are still not sure, a small scrape of the bark with a sharp knife will show either a green or darkened growth layer.  Cold-injured cambium layers under the bark will be black or brown in color; live tissue is green.  Prune these branches behind this point of discoloration.

In some cases, it will take some time for the buds to break after cold damage, so be patient before going crazy with winter-kill pruning.

Right Plant / Right Place

Finally, consider that a plant damaged beyond repair is actually an opportunity to try something different.  Florida homeowners enjoy a vast array of plant material choices.  We often choose the more exotic tropical appearance in our Florida Yards, and now we pay the price.  

Plants are rated by their cold tolerance, and the USDA Hardiness Zone Map  gives gardeners guidance on choosing the right plant based on cold temperatures.  Enthusiastic gardeners often plant past the northern limit in Florida.  For our area, dependably hardy plants are those rated for USDA Hardiness zone 9b or less.  These  hardiness zones are guidelines, as the microclimates in your area  may differ dramatically because of nearby windbreaks or bodies of water.  

Tropical and subtropical plants can be used effectively in Florida Yards, but they must be protected in cold years, or the homeowner must be prepared to replace them when the law of averages catches up with over-enthusiastic tropical tastes.

How about a compromise with Jack Frost: choose a combination of tender and hardy plants.  In this manner,  should a hard freeze occur, the total devastation of the landscape by extremely cold weather is avoided. 

 

Orchid Meeting Monday Night

Last month a very enthusiastic meeting was held at our office for persons interested in gardening.   To ward off the winter blues, why not come by our office on Monday January 25^th, 6:00 PM at the Okeechobee Extension office for another exciting evening of tropical horticulture.  The Garden club meets at 6PM: a special Guest speaker visits this month's Orchid Club at 7 PM.  There is no charge for this program, and it promises to be a great way to get together with a fabulous group of folks.

I’ve placed more information on our Okeechobee web page, http://okeechobee.ifas.ufl.edu.  If you need additional information on cold damage recovery, please email us at okeechobee@ifas.ufl.edu or call us at 863-763-6469.  Local residents can stop by our office at 458 Hwy 98 North in Okeechobee, and visit our Okeechobee County Master Gardeners from 1 to 3 PM on Tuesday afternoons.  GO GATORS!

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Trade names, where used, are given for the purpose of providing specific information. They do not constitute an endorsement or guarantee of products named, nor does it imply criticism of products not named. The Florida Cooperative Extension Service - Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information, and other services to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.  Florida Cooperative Extension Service / IFAS / University of Florida.  Millie Ferrer,Interim Dean Last update: 01/04/2010 .  This page is maintained by Dan Culbert 

 

References

Culbert, D. Gardening in the Zone.   Okeechobee News, July 5, 2007. http://okeechobee.ifas.ufl.edu/News%20columns/Heat.Zones.htm

Ingram, Dewayne L. and Yeager, Thomas H.  Cold Protection of Ornamental Plants [ENH1]. Gainesville: UF/IFAS Florida Cooperative Extension Service, 10/2003. http://edis.ifas.ufl.edu/MG025

Trenholm, L. E.  Low Temperature Damage to Turf [ENH-80]. Gainesville: UF/IFAS Florida Cooperative Extension Service, 5/2000. http://edis.ifas.ufl.edu/LH067

The Big Chill - Cold Protection of Ornamental Plants. Solutions for Your Life [website].  Gainesville: UF/IFAS Florida Cooperative Extension Service, 2/2007. http://solutionsforyourlife.ufl.edu/hot_topics/lawn_and_garden/cold_protection_of_ornamental_plants.html