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.
Palm trees are great for adding a tropical feel to your landscape. For the most part, they are easy to care for, however there are a number of environmental and nutritional factors that can affect palm tree growth. Extended drought conditions can cause palm trunk to contract or shrivel and extended periods of moisture can cause trunks to swell and crack.
A palm tree with an irregularly shaped trunk due to water stress. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Palm trees are monocots and do not have lateral meristems or vascular cambium. In dicot and coniferous trees these structures produce additional xylem (water transport structures) internally and phloem (nutrient transport structures) and bark externally. This means that once the apical meristem (frond producing portion of the palm) dies, the tree dies. It also means that wounds to the trunks of palms are visible for life instead of healing over like in dicots. If you were to cut the top out of a red maple, a number of it’s branches would fight to take over as the main trunk. If you were to cut the top out of a palm tree , you would be left with a dead snag for a tree. Palms certainly have unique structures and growing habits. Visit this publication from Dr. Timothy Broschat for more information on palm tree anatomy and morphology.
A palm tree with a wound near the base of its trunk. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Palm trees display nutritional disorders differently from other trees. Their nutritional balance gets disrupted if too much nitrogen is applied. This often happens when high nitrogen turfgrass fertilizers are applied near palm plantings. The recommended palm fertilizer is 8-2-12 (nitrogen-phosphorus-potassium) plus 4 magnesium all available in 100% slow release form. A soil test is recommended to determine if other micronutrients are needed in addition to magnesium.
Potassium-deficient older leaf of Dictyosperma album (hurricane palm) showing translucent yellow-orange spotting. Photo Credit: Timothy K. Broschat, University of Florida/IFAS
Potassium is one of the most common nutrient deficiencies observed in palm trees. For more detailed information on palm tree nutrient deficiencies please visit the publication: Nutrient Deficiencies of Landscape and Field-Grown Palms in Florida.
This article provides just a glimpse of some of the common issues that affect palms. For more information on what could be going on with your palm trees and general palm tree care please visit Ask IFAS: Palm Care.
The ancient cycad, coontie, is a hardy and attractive plant for Florida landscapes. Photo credit: Carrie Stevenson, UF IFAS Extension
The plant has a crazy-sounding name, more like some little animal you’d find in Australia than a native plant. However, an ancient Florida plant it is, and a tough one at that. Growing close to the ground, it most resembles a large fern or a sago palm, if the sago had smooth, rounded leaf edges. Like the sago, the coontie (Zamia floridana) is a cycad—a group of palmlike plants that have been around so long that triceratops and stegasauruses ate them! Coonties are the only cycads native to North America, found in the states and island nations like Cuba and the Bahamas.
Male cones (strobilus) of coontie are thinner and shorter than female cones. Photo credit: Dan Culbert, UF IFAS
Another interesting feature of the coontie is its seed cones. These are large reddish orange cones that resemble magnolia seedpods. Both sexes of plant produce them in clusters ranging from one to five of the 2-7” long cones. Cones from the male produce pollen, while females produce seeds. If you are interested in attracting wildlife to your yard, the coontie provides good low-growing cover for birds and small mammals. It is also the preferred food for the caterpillar of the rare Atala butterfly. Members of the Timucuan and Calusa tribes ground up the starchy root of the coontie as a flour. However, the root contains a toxin and if it is not removed first, ingestion could result in severe abdominal pain and vomiting. From the late 1880’s through World War I, a large starch industry existed in Florida, producing flour from the coontie root.
Adult female atala butterfly, showing royal blue streak on forewings. Photo credit: Sandy Koi, University of Florida
At home in drier soil conditions like oak hammocks and pinelands in north central Florida, these plants can also adapt to a variety of soil pH types. Coonties are drought, cold, and salt tolerant, thus a great landscape choice for coastal landscapes near the Gulf or a bay. The plants are very long-lived and adaptable. In fact, the book Florida’s Best Native Landscape Plants notes it is “Very hardy and easy to care for. Will grow well in any part of Florida, even outside its normal range. An exceptional replacement for the closely related, often used, but non-native sago palm.” In other words, this is an ideal landscape plant that should be used more throughout Florida.
Saw palmettos provide crucial ecosystem services for the forests of Florida. Photo credit: Carrie Stevenson, UF IFAS Extension
The saw palmetto (Serenoa repens) is a classic symbol of Florida. Found in upland habitats and just to the edge of wetlands, their brilliant green fronds stand out in the mostly brown pine flatwoods and oak hammocks to which they are endemic. The shrublike saw palmetto thrives in sandy soils, is highly salt tolerant, and is tough as nails. The plant’s root is one of the sturdiest in nature. Imagine the trunk of a palm tree laid horizontally and just underground—this is the plant’s base. This root system lends stability and tolerance to nearly every tough Florida growing condition, including drought, floods, and fire. Saw palmettos are extremely slow growing, and there are stands in south Florida in which botanists have found individual plants and clonal colonies several thousand years old. Saw palmettos are one of the few members of the palm family that thrive in the panhandle. While many palm trees are planted here, most are native to more southern climates with warmer winters and karst geology—a higher pH soil composed of limestone and often prone to springs and sinkholes.
The tough, serrated edges of the saw palmetto gave it its name. Photo credit: Carrie Stevenson, UF IFAS Extension
The saw palmetto’s name comes from the serrated, saw-like edges of the stem. These are quite tough and can cut your skin and clothing if not careful. A very similar palmetto, the bluestem, grows in wetter soils. It can be differentiated from the saw palmetto because its stems are smooth—no serrated edges—and the whole plant has a bluish cast to it.
The saw palmetto has long been prized by humans for its practical uses. The “ethnobotanical” history of this plant has ties to Native American tribes who used the fronds for roofing and building material, brooms, fishing nets, and fans. The leaves were utilized for rope, and multiple plant parts for food and medicine. The dark blue/black fruit of the saw palmetto was considered an aphrodisiac and has been used to treat prostate problems for centuries. According to a UF publication on the saw palmetto, “Modern day development of a purified extract from the berries greatly improves symptoms of enlarged prostate. Florida is the biggest source and producer of saw palmetto products. With about 2,000 tons harvested from South Florida and exported to Europe each year, the fruit crop estimate is $50 million a year in the state.”
Saw palmetto berries are a staple of Florida wildlife diets. Photo credit: UF School of Forest Resources & Conservation
Besides the human uses, saw palmetto serves as a crucial component in the diet of native wildlife. Florida black bears, panthers, 20 other species of mammals, over 100 types of birds, 25 amphibians, over 60 reptiles, and countless insects depend on saw palmetto berries as part of their diet. The wild harvest of saw palmettos is regulated by the state to prevent overharvesting and negative impacts to the wildlife food supply.
Saw palmettos also make a great home landscape plant, as they can grow in a wide variety of conditions, provide wildlife food and habitat, and add visual interest. There are few plants more “low-maintenance” than an established saw palmetto. A mature one is so difficult to remove, that it’s best to leave it where it is anyway!
Scale insects on a cabbage palm (Sabal palmetto). Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
This week I was on a couple site visits to look on some cabbage palms (Sabal palmetto) and some banana shrubs (Michelia figo). The palms had a white, waxy substance on their frond petioles and the banana shrubs had white specs on the tops of their leaves. Upon further investigation, I realized the waxy substance and specs were both different species of scales. Scale insects are serious pests of a number of ornamental plants. Here in Florida there are 13 different families of scales with the most common being armored scales, soft scales, and mealybugs. Scales have piercing-sucking mouthparts which they use to siphon fluids from the leaves, stems, and sometimes roots of many ornamental plants. Heavy infestations cause extensive leaf yellowing, premature leaf drop, branch dieback, and eventually plant death.
Scale Biology
The life cycle of a scale begins with eggs being laid beneath wax coverings or beneath the adult female. Eggs typically hatch in 1 to 3 weeks. The newly hatched nymphs, called crawlers, move around a plant until they find a spot to feed. Once a feeding site is located, their piercing sucking mouthparts are inserted into the plant and the crawlers begin to feed and grow. The males of many scale species develop wings as adults and fly to other plants to reproduce.
Magnolia white scales on a banana shrub (Michelia figo). Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Armored Scales
Armored scales get their armor by secreting a waxy covering over their bodies that is not attached. The scale lives under this covering and uses it as a protection to feed under. Armored scales can be almost any color or shape and range anywhere from 1/16 to 1/8 inch in diameter. For females, these shapes range from circular to oval to long and slender. The males typically have coverings that are more elongate and smaller than the females. As adults, the males are tiny, winged, gnat-like insects and are rarely seen.
Gloomy scale (Melanaspis tenebricosa) with armored covering removed. Photo Credit: A. G. Dale, University of Florida/IFAS
Soft Scales
Similar to armored scales, soft scales secrete a waxy covering, but it is attached to their bodies. Soft scales can be a number of colors, shapes, and sizes and range anywhere from 1/8 to 1/2 inch in diameter. Their shapes vary from spherical to nearly flat.
Population of adult and immature tuttle mealybugs (Brevennia rehi) on a blade of zoysiagrass. Photo Credit: Lyle J. Buss, University of Florida/IFAS
Mealybugs
Mealybugs are soft-bodied insects that possess a covering of flocculent, white, waxy filaments. They are about 1/8 inch in length and usually pinkish or yellowish in color. Mealybugs have piercing-sucking mouthparts which they use to siphon fluids from the leaves, stems, and sometimes roots of many ornamental plants. Mealybug damage produces discolored, wilted, and deformed leaves.
Scale and Mealybug Management
Larva of a brown lacewing. Credits: Lyle Buss, University of Florida.
For insect identification and additional information on scale control, please see: