Video: Freeze Damage to Homeowner Citrus

Video: Freeze Damage to Homeowner Citrus

Temperatures in December 2022 were very damaging to many citrus in North Florida. It is necessary to give plants plenty of time into spring and summer to see if they will regrow and where that growth will occur. Learn how to care for your citrus that is suffering from cold temperature damage with Beth Bolles, UF IFAS Extension Escambia County.

Getting Your Plants Through a Freeze

Getting Your Plants Through a Freeze

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!

Video: Cold Weather Damage Plant Care

Video: Cold Weather Damage Plant Care

The North Florida garden has experienced some cold weather damage and even though you want to start pruning back your perennials, now is not the time. Many damaged plant stems protect perennials that return from the roots. Learn about care of cold damaged plants with UF IFAS Extension Escambia County In the Garden. #colddamage #coldprotections

Palms Can Suffer in the Cold

Palms Can Suffer in the Cold

Medjool Palm LandscapeWhile palms may survive, or even thrive, for years in climates cooler than those to which they are native, eventually they will experience temperatures cold enough to cause injury. Here in Northwest Florida, it was January 2014.  Unfortunately, much of the damage was not evident until the summer of 2015.  The palms held on with stored food reserves.

When cold damage is severe, plant tissues are destroyed and water uptake into the plant may be reduced for years. Many times it is only the protected bud that will remain alive.  The stem slowly weakens until it can’t support the weight of the crown and it collapses.palm collapse

Winter is upon us again. So, if you still have palms in the landscape, be prepared, should we experience some extreme weather.  Here’s a reminder of what to do.

One of the most common problems associated with freezes is that the freeze-killed lower portion of the spear leaf is degraded by secondary fungi and bacteria that are always present in our natural environment. Palm owners are often anxious to trim off the damaged leaves following a cold weather event.  Avoid the temptation to remove these fronds until danger of additional freezes has passed.  Even dead leaves provide insulation to the critical bud.

As the weather warms, the dead fronds need to be removed from around the bud so that the spear can begin to dry out. Drenching the bud area with a copper fungicide will reduce the secondary microbes.  Repeat applications will need to continue as the palm leaves develop.  Copper fungicides, unlike other fungicides, are active against bacteria and fungi.  Be cautious to not use a copper nutrient spray rather than a fungicide.  Delay fertilizer application until new fronds have developed.  The best analysis for palms is 8-2-12 + 4Mg.  Utilization of proper palm fertilization can improve cold hardiness of palms.

Palms damaged by cold can still show symptoms six months to a year following a freeze. New leaves in the spring may appear mis-shaped.  Usually the palm will outgrow the damage.  However, sometimes the palm loses its ability to take up water.  If there is a sudden collapse of the fronds in the crown during the first hot days, the palm may die.  There is nothing that can be done to save the palm.

 

Camellia Flowers that Fail to Open

Camellia Flowers that Fail to Open

Do you have camellia plants with flower buds that fail to open? Here are possible causes for this problem.

  • Stress – Drought is the primary stress that inhibits buds from opening.
  • Too many buds on a plant results in the plant not having reserves for each bud to open.
  • Warm weather during fall may inhibit early blooming varieties from flowering properly.
  • Freeze damage – Most of our Camellia japonica cultivars produce flower buds and bloom during the winter. As the flower buds begin to swell, and particularly as they begin to open, the flower buds become more susceptible to freeze injury. Freeze injured flower buds fail to open. Also, plants located in colder areas of the landscape will be more susceptible to cold injury. Camellia sasanqua cultivars are less likely to experience cold injury to their flower buds because they bloom mostly during fall and early winter when we are less likely to experience freezing temperatures.

    Partially opened freeze injured camellia flower, Photo credit: Larry Williams

    Partially opened freeze injured camellia flower, Photo credit: Larry Williams

    Partially opened camellia flower bud with discolored (brown) petals due to cold injury, Photo credit: Larry Williams

    Partially opened camellia flower bud with discolored (brown) petals due to cold injury, Photo credit: Larry Williams

    The early freeze that occurred during mid November 2014 and the more recent freeze in early January 2015 may be responsible for some of the flower bud injury on earlier and later blooming camellia plants here in north Florida this season.

  • Another situation may have to do with the specific variety. Thirty plus years ago people planted any camellia they could find because there was a more limited selection. Even though camellias have been part of our southern landscapes for many years, they are native to parts of Asia. Over the years there have been more introductions of cultivars. Some are not well adapted to our colder winters. Some camellia cultivars are not well adapted to the gulf coast and thus won’t flower well even though they may grow well here. This is why some varieties are favored in Seattle, some do better in England and others perform well here. You’d be wise to select cultivars that are known to do well in our area.

For more information on camellias, contact the UF/IFAS Extension Office in your County or visit http://edis.ifas.ufl.edu/ep002 to access the publication, “Camellias at a Glance.”