No plant is as closely associated with Florida as a palm tree – the native sabal palmetto is the state tree, in fact! While this and several other species of palm are hardy even into the cooler regions of the panhandle, there are occasionally problems that arise with them. Palms tend to be sturdy in the wind, handle salt spray, and deal with drought without much issue. A few diseases can strike them, however, and the fungal pathogen Ganoderma zonatum is one of them.
Symptoms of a tree infected with Ganoderma butt rot. Image credit: M.L. Elliott
Ganoderma butt rot, caused by this pathogen, can affect any palm tree no matter the species. It only attacks palms, so nearby hardwoods or conifers are safe from it. As a fungal disease, it spreads by spores, which are produced on a conk (a type of mushroom that is wide and flat, usually growing on decaying wood). By the time the conk is visible on the trunk of a palm, the damage is done. The fungus slowly rots away the lower four to five feet of the trunk, working invisibly until it is ready to reproduce. The trunk of the palm will not become soft or spongy as the disease develops. There may be other outward symptoms of the disease, including slower growth, off-color foliage, and wilting and dying of fronds starting from the older bottom fronds. These symptoms occur with other diseases and problems as well, making it difficult to diagnose Ganoderma butt rot until the conk is visible.
A conk will start out as a small, white, button-like growth on the trunk. As it grows, it expands, flattens out, and develops a brown or reddish-brown coating on top. Old conks turn fully brown. It is uncertain how long it takes a newly infected palm to develop conks; it may be months or even years.
Once a tree is infected with this fungus, there is no cure. Removal of the tree is the only option, and as much of the trunk, stump, and roots as possible should be taken out. Conks may form on stumps after the palm is cut down, which can help to spread the disease. The fungus, unfortunately, persists in the soil even after the palm is removed, so infected palms should be replaced with other types of plants.
A small, relatively newly formed conk.
Frustratingly, the disease is difficult to predict. There do not seem to be any conditions that favor the disease in particular – it has been observed on otherwise healthy plants as well as stressed ones, and on naturally growing palms as well as those that have been transplanted. Still, keeping plants of any sort as healthy as possible can help them to resist pests and diseases, so fertilize, irrigate, and prune palms properly.
While palms may survive, or even thrive, for years in climates cooler than those to which they are native, eventually they may experience temperatures cold enough to cause injury. The January 21st snow and wind chill is likely to take a toll on many of the palms in Northwest Florida. We have experience with this since it also happened in January 2014 and December of 2022. Unfortunately, much of the damage in 2014 was not evident for 18-24 months and we are not out of the window for 2022. Healthy palms can hold on with stored food reserves, but repeated events can continue to weaken them. 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. These palms can still be saved if the bud remains alive. Winter is not over, even though the temperatures are now creeping higher and higher. So, evaluate what damage you may already have and prepare for any additional, yet to come. 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.
Palm trunk decay appeared 2 years after 2014 freeze.
Palms damaged by cold can still show symptoms six months to three years following a freeze. New leaves in the spring may appear misshapen. 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.
On March 7th we held our second Gardening in the Panhandle LIVE! of 2024 and the panel tackled Palm Selection and Care. We had lots of great questions from viewers, and this is a recap of some of the main points covered and references shared.
A few spoilers of the discussion – palms are not trees, they are grasses; and Sago “palms” and Coontie “palms” are cycads, not palms! Check out the video for explanations.
Although there is always the possibility of cold damage if winter temperatures drop below average, for the best success choose palms more likely to survive “normal” winters. These include Cabbage Palm, Mule Palm, Pindo Palm, Needle Palm, and Windmill Palm.
Maintaining palms can also be tricky – especially if you are performing tasks out of routine rather than need.
Pruning palms is a hot subject because it is very commonly done incorrectly leading to nutrient deficiency, bud exposure to cold and wind damage, spread of disease, and attracting insect pests. Proper techniques can be found in Pruning Palmshttps://gardeningsolutions.ifas.ufl.edu/care/pruning/pruning-palms.html
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:
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.
The hottest days of the summer are here and you might be thinking, “There is no way something could survive this heat!”. You might also be wondering “What can I do in my landscape?” Well, you are correct – it is hot and there are not many plants that thrive in this type of weather, but the good news is we are at the end of the summer season and there are things we can begin to do to get ready for fall. It’s not too late to get the last of the summer vegetables going such as lima beans, cucumbers, eggplants, and peppers. Many cool season crops can also be planted by seed now and tomatoes will thrive going into the fall season. See Vegetable Gardening in Florida
There are some heat-tolerant annuals like vinca, gaillardia, bulbine, and coleus that can be planted now in the landscape. See Annuals. Any time of the year, even late summer, bulbs like Aztec Lily, Butterfly Lily, Walking Iris, and Spider Lily can be planted. See Bulbs for Florida. Not many herbs do well in our Florida sun this time of year, but Bay Laurel, Ginger, Mexican Tarragon, and Rosemary can be planted as transplants now but not as seeds just yet. See Herbs.
August and late summer is the time of year that you may be seeing damage in your lawns. This could be caused by insects, disease, or irrigation failure. It is important to determine the cause, so the proper remedy is used. Some ways to avoid lawn damage are checking your mower blades regularly and making sure they are sharp. Also only cut the top one third of the blade of grass to not stress it in the heat of the day. It is good practice to test your irrigation clock and have a rain sensor. Some municipalities in north Florida prohibit the application of fertilizer during the summer rainy season from June to September so check with your local extension office. See Insect Management in Your Florida Lawn
You can become more self-sufficient by growing your own healthy food in your backyard. Photo by Molly Jameson.
There are some other maintenance measures you can take in August to help your landscape and prepare for the fall season. If older palm fronds are yellowing, this could indicate a deficiency in magnesium or potassium. Talk to your local agent or visit your local store for an appropriate palm fertilizer. See Palm Nutrition and Fertilization. Are you holding on to those beautiful fall mums or decorative Christmas poinsettias? Now is the time to pinch them back to allow time for buds to set for winter blooms. Finally, it is a good time to deadhead (remove old blooms) and fertilize flowering annuals and perennials. We’ve had substantial rain this summer, so keep in mind that the soil could be lacking nutrients. A soil test can give you data that indicates what you need for the up-and-coming growing season.
