The widespread multiple night hard freeze that occurred in North Florida near the end of December 2022 resulted in numerous citrus trees becoming severely damaged. The above ground portion of many of these trees died as a result of the extreme cold.
I talked with numerous homeowners who were concerned about their citrus trees following that weather event. Many of these homeowners earnestly and hopefully watched for any sign of new growth on their cold injured citrus trees the following spring. When new growth appeared from the lower portion of the trunk and from the roots, the homeowner became excited with a false sense of hope that their citrus tree had survived and would again produce an abundance of desirable fruit.
Cold injured citrus tree with new growth coming from rootstock. Credit: Larry Williams
Now in the spring of 2024, many of these citrus trees have somewhat regrown from those root shoots, not from the completely dead tops. In most cases, the freeze damaged, dead tops of the once large trees have now been pruned away to allow the multitude of small diameter vigorous green shoots to grow.
Most purchased citrus trees are grafted. So, what survived and is now regrowing is coming from the rootstock, not from the original, desirable, edible fruit producing top. That desirable top was completely killed.
To better understand this scenario, perhaps a basic definition of grafting will help. This definition was taken from a University of Missouri Extension publication on grafting. “Grafting is the act of joining two plants together. The upper part of the graft (the scion) becomes the top of the plant, the lower portion (the understock) becomes the root system or part of the trunk.” Understock is also known as rootstock.
Grafting involves joining two different individuals. These individuals have to be closely related. For example, citrus can be grafted to other types of citrus and peaches can be grafted to other types of peaches. But citrus cannot be grafted to peaches.
The rootstock was selected because of some beneficial trait(s): resistant to a root pest, superior cold hardiness, imparts a dwarf growth habit to the top, etc. But the same rootstock produces undesirable fruit: bitter, hard, extremely seedy, etc. The top (scion) was selected because of a superior fruit: sweeter, bigger, more disease resistant, etc. But the same scion produces an inferior/weak root system. So, grafting the two together allows for the “best of both worlds.”
When all that is left is originating at or below the graft union or rootstock, the eventual resulting fruit will usually be undesirable, sometimes not edible.
So unfortunately, the best option in this scenario is to start over with another healthy grafted tree that is well suited for the potential cold weather of extreme North Florida.
Fall, winter and even early spring can be a rollercoaster ride of temperatures here in Northwest Florida. One week it dips to freezing for a short time and the next week it rises to spring-like temperatures. We need to hold on for this ride of up and down temperatures and not overreact too soon.
Following the sudden ride down to the lower temperatures, we may think winter is over. But we don’t see the next drop in temperatures that’s coming, as we are experiencing the ride upwards in temperatures.
On average, it’s not until we reach mid-March that we expect our last killing frost. A killing frost is heavy enough to kill tender plant growth. And, we can have light frosts well into the latter part of March and into early April. This is particularly true in the more northern portions of our Panhandle Counties.
The main point is to not get spring fever too early and encourage new plant growth by pruning or fertilizing too soon.
When landscape plants freeze, the first impulse may be to get out the pruning shears and cut away dead and dying leaves and branches. But this isn’t a good idea. Pruning can force new tender growth that is more likely to be injured by the next freeze. And, you can’t tell how much damage has been done until plants start new growth in spring. If you prune immediately after a freeze, you may cut away live wood that doesn’t have to be lost. Also, leaves and branches, which have been killed, can help protect the rest of a plant against further cold injury.
Some people want to “jump start” their lawns before our weather will allow our grasses to grow. Waiting allows for more efficient use of the lawn fertilizer. You will not injure your lawn by waiting but you can certainly injure your lawn by fertilizing too early.
So, have patience, allow your lawn to green up on its own and then fertilize, even if it’s not until April or May.
Finally, be a little philosophical. If you do lose one or two of your tender ornamentals, so what? Worse things could happen. And now you have a chance to add something new, perhaps some species native to our area that is not as subject to cold damage.
Even with this winter/spring rollercoaster ride, with thousands of plants to choose from and a generally mild climate, who can complain?
Interest in cultivating date palms in North Florida is on the rise. Highly regarded by gardening enthusiasts, the date palm is grown as an ornamental and for its delicious fruits with the added bonus of medicinal properties.
Growing date palm in North Florida poses challenges due to the region’s moist and cooler climate with temperatures occasionally dipping below freezing. Date palms, which typically thrive in hot, arid conditions, include two notable species: True date palm (Phoenix dactylifera) renowned for its tasty fruit and the Canary Island date palm (Phoenix canariensis), known for its substantial size and edible but less flavorful fruits. There is also (Phoenix sylvestris), known as the Sylvester date palm or wild date palm.
Date palm damaged by freezing temperatures. Photo by Beth Bolles, UF IFAS Extension Escambia County
Characterized by a slow growth rate, date palms can, in certain environments, grow to towering heights of up to 80 feet. Their pinnately compound leaves, ranging from blue-green to gray-green, can stretch up to 20 feet in length, featuring leaflets of 1 to 2 feet that form a distinctive “V” shape along the rachis. Date palms possess ornamental appeal, thanks to its textured trunk, striking blue-green foliage, and vibrant orange inflorescences. However, date palms do generate some concern because of the litter created by its fallen fruits. Its wide crown offers limited shade due to its relatively sparse canopy.
To flourish, date palms require well-drained, neutral to acidic soil and an abundance of direct sunlight. A plus is their ability to thrive in confined root spaces. North Florida’s sporadic frost and cold spells necessitate protective measures for date palms during the colder months, such as covering them with frost cloth or employing mulch around the base to insulate the roots. Some palm enthusiast grows them in sheltered location but occasional freeze damage to foliage can be expected.
Alternatives
Gardeners in North Florida seeking a cold-hardy alternative might try the pindo palm (Butia odorata), which is an excellent choice. Although it isn’t a true date palm, its feathery fronds provide a tropical ambiance to the landscape. Other palm species adaptable to North Florida’s wintry conditions include windmill palms, needle palms, and sabal palms. These options vary in their ultimate height and visual characteristics.
While it’s possible to grow date palms in North Florida, it’s important to understand that success may not be guaranteed, and you may need to provide extra care and protection to help your trees thrive in the region’s climate.
For more information contact your local extension office or visit:
Some citrus is recovering from our December 2022 hard freeze and pruning will be needed. Learn to identify your tree’s graft and how to prune away any rootstock material with UF IFAS Extension Escambia County.
Palms in North Florida suffered serious damage as a result of freezing weather in December 2022. As spring approaches, we will be looking to see if the palms will recover. Learn what to do now and what to expect from your palms with UF IFAS Extension Escambia County.
There are important landscape lessons to learn from recent, early and widespread freezes.
First, know the average climate for the region you live in here in Florida. The work has already been done for you with the USDA Plant Hardiness Zone Map. Here is a link for the map: https://planthardiness.ars.usda.gov. Find your zone on the map. Note that Northwest Florida includes zones 8a, 8b and 9a.
The newest map, with interactive features, was updated in 2012.
This map is based on the average annual minimum winter temperature and is divided into 10°F zones. It can help you determine which plants are most likely to thrive in your zone. There are areas bordering Alabama, located in the extreme northern portions of Escambia, Santa Rosa, Okaloosa, Walton and Holmes Counties, that are in Zone 8a, with an average annual extreme minimum temperature of 10 to 15 degrees F. Most of these counties fall within zone 8b, with an average annual extreme minimum temperature of 15 to 20 degrees F. The extreme southern portions of these same counties (bordering the Gulf) are in Zone 9a with an average annual extreme minimum temperature of 20 to 25 degrees F. As you go south in Florida, you move into Zones 9b, 10a, 10b, and 11a. Zone 10b has an average annual extreme minimum temperature of 35 to 40 degrees F. Zone 11a; which includes a small portion of West Palm Beach and Fort Lauderdale, most of Miami and all of the Florida Keys; has an average annual extreme minimum temperature of 40 to 45 degrees F.
Most of the Panhandle is in USDA Hardiness zone 8b.
It seems that some people move to extreme north Florida and think they are in extreme south Florida. They move barely below Alabama or Georgia and want to plant the palms, citrus and tropical plants that thrive in extreme south Florida. If you live in Zone 9a, perhaps you might get by with growing a few plants that are well suited for 9b. But it is wise to mostly grow plants that are known to flourish in the Plant Hardiness Zone where you live.
Secondly, follow principle one, which is Right Plant, Right Place, as explained in the UF/IFAS Extension Florida-Friendly Landscape™ (FFL) Program. Following this principle results in developing a healthy, low-maintenance landscape by using Florida-Friendly plants that match your site’s soil, light, water and climatic conditions and that require limited supplemental irrigation, potentially less fertilizer and fewer pesticides.
More information on the FFL Program is available through this UF/IFAS Extension link (https://ffl.ifas.ufl.edu) or from the Extension Office in your County.
Using these tools may be a great goal for 2023 as we replace cold-injured plants.
