by Ben Hoffner | Sep 11, 2025
Photo credit to Daniel Leonard, Calhoun County Extension Agent
When maintaining proper care of your trees and shrubs in your lawn or landscape it is important to not damage stems and trunks. It is best practices to keep the area around the tree clean, but it needs to be done properly. Mowing and weed eating is not recommended due to the possibly of severe damage to the trunk and stems. Repeated damage from mowers and weed eaters cause damage called girdling. There are a few very effective ways to protect the trunk and stems from damage such as mulching and using tree rings/tubes.
Repeated damage to the base of the tree and stems will affect the cambium layer. The cambium layer is a thin layer of living tissue directly under the bark of the tree, and it supports the growth and well-being of the tree, actively dividing cells located between the xylem (wood) and phloem(bark). Constant damage of this layer will cut off the flow of carbohydrates to the roots, which will cause the tree to die. This layer is the green material you see after the bark of the tree has been damaged. It is imperative to keep the cambium layer damage free to insure the best tree health.
Photo credit to Daniel Leonard, Calhoun County Extension Agent
Taking preventive measures will ensure the prolonged life of your tree. Using mulch around the perimeter of the tree for protection from injury is the most effective method of protection. There are different mulch types like straw, bark, leaves, needles, wood or grass. These are examples of organic mulches. Tree rings and tubes can be helpful to protect young trees. If mulch is not the best option for the plant, other materials such as cut sections of plastic pipe or rubber tires could be an option for protection.
Mulch is not only a great way to protect your trees from injury. It also helps with retaining moisture, erosion control, weed suppression, organic accumulation and aesthetic appeal. Following simple guidelines when using mulch will make sure that you are maximizing the material used. Maintain a 2-to 3-inch layer around your established trees. Avoid “volcano mulching”. “Volcano mulching” is when mulch is piled against the base of the tree, it holds moisture. High amounts of moisture can cause the trunk to rot.
To prolong the life of your trees and shrubs you must protect them from injury that can cause girdling. Avoid constant contact with lawn mowers and weed eaters that will destroy the cambium layer. Using mulch is a very effective way for protection as well as retaining moisture, erosion control, weed suppression, organic accumulation, and aesthetic appeal.
For more information contact your local UF/IFAS Extension Office.
by Mark Tancig | Aug 28, 2025
A healthy coneflower in Leon County’s Demonstration Garden. Credit: Jessica Thrasher
My last Gardening in the Panhandle article was about the many diagnostic services provided by UF/IFAS Extension. In this article, I get to share the results of those services concerning samples recently submitted to the North Florida Education and Research Center (NFREC) Plant Disease Diagnostic Clinic (PDC).
Anthracnose in Dogwood (Cornus florida)
Before you get too concerned, this is not the dogwood anthracnose (Discula destructiva) that many of us have heard about from friends and colleagues up north, but one of the more common anthracnose species (Colletotrichum gleosporoides) that infects a variety of fruits, vegetables, and ornamentals.
Typical leaf symptom of common anthracnose disease on a magnolia. Credit: UF/IFAS.
This sample came from a homeowner who brought us a branch from a sick looking dogwood. As many of you know, due to a host of issues, from a short lifespan to living in the southern end of its range in a warming climate, dogwoods have been faring pretty bad lately, with most landscape plantings showing signs of decline or death. While Florida extension agents are informed that it is not the terrible anthracnose from up north, some couldn’t help but think the worst. I was delighted to get a good sample for identifying the disease – one that showed both healthy tissue and diseased tissue – and finally confirm what is causing the common decline symptoms seen in Leon County dogwoods. We bagged up the sample and delivered the next day to the NFREC PDC.
Within a week, the results came back and confirmed the run-of-the-mill anthracnose. This Anthracnose, caused by the fungus Colletotrichum gleosporoides, causes lesions (spots) and/or blights (larger areas of the leaf browning) beginning at the leaf margins that tend to expand and end up causing premature leaf drop. Unfortunately, once we see the damage, typically in the summer, it is too late for any remedy, as the infection begins in the spring. In addition to good practices to encourage good airflow – proper spacing, pruning – and minimize moisture on leaves – irrigate the soil, not the leaves, water in the morning – you will also need to be able to handle some amount of damage. Removing fallen leaves and branches is also helpful to reduce the chance of it cycling back the following spring. Chemical control options include 2-3 applications of preventative fungicide sprays containing chlorothalonil, myclobutanil, mancozeb, or thiophanate methyl early in the spring according to label directions.
Aster Yellows in Purple Coneflower (Echinacea purpurea)
The deformed blooms of a coneflower with Aster Yellows. Credit: Jessica Thrasher
I’ve had a few questions about Aster Yellows (Candidatus phytoplasma asteris) over the years but have never positively identified the disease in plant material. So, I was somewhat excited to see some of the purple coneflowers in our demonstration garden showing peculiar symptoms. Actually, I was alerted to the strange looking plants by a Master Gardener Volunteer who had been weeding the area. We delivered a sample to the NFREC PDC and in just over a week had results.
Aster Yellows is a disease caused by a phytoplasma and the sample can only be diagnosed with molecular techniques and genetic sequencing. Phytoplasmas, by the way, are a type of bacteria that lack a cell wall and are transmitted plant to plant via insect vectors, typically leafhoppers. Once inside the plant, these phytoplasma can move with plant sap and begin to disrupt the vascular system, causing malformed and discolored flowers, plant deformations, and stunted growth. While members of the Aster family – daisy, sunflower, goldenrod – are common hosts of the disease, Aster Yellows has been found to infect over 300 species in at least 38 plant families. Other species of phytoplasma, also causes lethal yellowing and lethal bronzing of palms and several witch’s-broom diseases.
Since there are not any chemical treatments for Aster Yellows, prevention is key. Once observed, it’s best to remove the infected plants as soon as possible to prevent spreading to other nearby species. In agricultural settings, the leafhopper spreading the bacteria becomes the main target to control using various insecticides. However, in ornamental settings, simply removing the infected plants is the recommended practice.
Stay Observant
Many common diseases are present in every landscape. By ensuring soil and plant health, many of these diseases can be tolerated with little damage. It is important for gardeners and landscapers to be on the lookout for problems so they can be dealt with before they get out of hand. UF/IFAS Extension provides assistance through our county offices and diagnostic clinics to help confirm identification of the pest and provide science-backed control options. If you think you have an issue in your landscape, please reach out to your local county extension office.
Article co-authored by Fanny Iriarte, Diagnostician with NFREC PDC.
by Donna Arnold | Aug 15, 2025
Kalanchoe Species in Florida: Invasive Threats and Management
Several species of Kalanchoe, widely distributed through horticulture as popular containers and landscape plants, have escaped cultivation and become invasive in Florida. Of the approximately seven species reported outside of cultivation, two have been documented as particularly problematic: Kalanchoe pinnata (commonly known as Cathedral Bells) and Kalanchoe × houghtonii (known as Mother of Millions). Both are listed as Category II invasive plants by the Florida Invasive Species Council (FISC), indicating they have the potential to disrupt native ecosystems. “In Central and South Florida, the plant is listed as invasive; hhowever, there is a cautionary note for North Florida.”
Photo Credit: Donna Arnold, FAMU Extension
Kalanchoe × houghtonii is a hybrid of K. delagoensis and K. daigremontiana, which has led to some confusion in reporting and distribution records. These species belong to the Crassulaceae family and are characterized as succulent herbs with hollow, fleshy stems. K. pinnata features rounded, scalloped leaves, while K. × houghtonii has slender, pointed, fleshy leaves. Their bell-shaped, pendulous flowers range in color from green to red. In Florida, these plants are primarily found in South Florida and along the East Coast, extending as far north as Nassau County.
Photo Credit: Donna Arnold, FAMU Extension
The ecological impacts of Kalanchoe species are significant. Reproduction occurs both sexually and vegetatively, with plantlets forming along leaf margins and even on inflorescences. This species high reproductive rate and ability to thrive in dry, arid environments allow them to invade coastal dune habitats, where they form dense carpets that crowd out native species. Shallow root systems contribute to destabilization of sandy areas by displacing native plants such as sea oats, which are essential for anchoring sand and preserving dune integrity.
Effective management begins with prevention. Homeowners are advised not to plant Kalanchoe species and to avoid dumping landscape material in natural or disturbed areas. Physical control methods include hand-pulling and secure disposal of plant material to prevent regrowth. Chemical control can be achieved using a 5% glyphosate foliar spray, which is effective in killing individual leaves that might otherwise produce new plantlets. Follow-up removal of detached leaves is essential to prevent further spread. Currently, there are no known biological control methods for these species.
For more information and personalized management recommendations, homeowners should consult their local UF/IFAS Extension office. Additional resources are available through the UF/IFAS Center for Aquatic and Invasive Plants, and the Florida Invasive Species Council Plant List.
by Donna Arnold | Jul 6, 2025
Zinnia Woes: What’s Causing Terminal Shoot Curling?
On a quiet stroll to the greenhouse early Monday morning, something unusual caught my eye—our zinnia plants looked noticeably different. Their vibrant green shoots had begun to curl at the tips, a subtle but clear sign that all was not well. Do not be alarmed if your zinnias are showing similar symptoms—it is a common issue. Curling at the terminal shoots is often a plant’s way of signaling stress. Whether it is due to environmental factors, pest activity, or nutrient imbalance, these twisted tips are clues worth investigating. Understanding the “why” behind the curl is the first step toward helping your zinnias return to their radiant, blooming selves
Common Culprits Behind Curling Zinnias
Environmental Stress: Zinnias are sun-lovers, but extreme heat, strong winds, or sudden temperature swings can cause their terminal shoot to curl as a defense mechanism.
Watering Woes: Both overwatering and underwatering can lead to leaf curls. Too much water suffocates roots, while too little causes drought stress—either way, the plant reacts by curling its leaves.
Pests: Aphids, thrips, and spider mites are notorious for feeding on tender new growth. Their sap-sucking habits distort leaves and can transmit viruses.
Diseases: Fungal infections like powdery mildew or bacterial leaf spot can cause curling, especially when combined with poor air circulation.
Nutrient Deficiencies: A lack of nitrogen, magnesium, or manganese can lead to curling and yellowing of new growth. Soil testing can help pinpoint the issue.
What You Can Do:
- Ensure consistent watering—moist but not soggy soil is ideal.
- Inspect regularly for pests and treat with neem oil or insecticidal soap.
- Improve air circulation by spacing plants properly and pruning overcrowded areas.
- Feed with a balanced fertilizer and consider a soil test if symptoms persist.
- Remove and destroy severely affected plants to protect the rest of your garden.
Healthy zinnias reward you with bold, cheerful blooms. A little detective work now can keep your garden dazzling all season long. For more information on Zinnias, contact your local Extension office or follow the links below.
https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/zinnia/
https://edis.ifas.ufl.edu/publication/FP623
https://nwdistrict.ifas.ufl.edu/hort/category/annuals-2/page/2/#:~:text=When%20planting%20zinnias%2C%20it’s%20recommended,than%20the%20foliage%20whenever%20possible.
by Abbey Smith | Jun 5, 2025
The Florida Panhandle’s warm, humid, and sunny climate makes it ideal for lawns to stay lush and green for most of the year—but it’s also perfect for turfgrass diseases to develop. The summer weather has already been ramping up with temperatures reaching a little above 90 degrees Fahrenheit already this year which also means the signs of disease will be showing sooner rather than later. If you’ve been noticing large brown patches, thinning grass, or strange spots growing on you grass leaves, a disease may already be present. Here’s what you need to know to stay ahead of a total lawn takeover.
Large patch or rhizoctonia blight is one of the most common fungal turfgrass diseases to affect lawns, specifically if you have centipede turfgrass. This disease is most prevalent between the months of November and May, and if not controlled, will continue to spread in the fall. Symptoms are easy to spot, as large, brown circular discolorations that will grow larger in size over time. The best way to treat large patch is through preventative lawn maintenance over time. Water only when necessary to avoid excess moisture, apply slow-release appropriate lawn fertilizers, and clean your mower blades after each time you mow.
Large patch disease present in turfgrass. Photo Credit: Shelia Dunning, UF/IFAS Extension
Another common lawn disease to see during the warmer months is dollar spot. Dollar spot will affect all warm season turfgrasses but will be more commonly found in Bahia and Bermuda grass. Dollar spot disease creates small patches that are circular and will grow into larger areas. Individual grass leaves will have small lesions starting on the leaf margin that will have a light brown to tan coloration. It is important to know that grasses that are drought stressed, over irrigated, or mowed too low are more prone to contracting this disease. Proper cultivation practices are important to prevent dollar spot and other turfgrass diseases. For more sever cases, the use of chlorothalonil fungicide can be used during the treatment process.
There are various other lawn diseases that can be recognized over time. If you are trying to identify a potential disease in your lawn grass, consider using the UF Turfgrass Disease Identification Flowchart. It will walk you through the symptoms that are present to make a correct diagnosis. If you would like a more expert opinion, contact your local county Extension office for additional help. For additional information on turfgrass diseases, please visit:
https://sfyl.ifas.ufl.edu/media/sfylifasufledu/baker/docs/pdf/horticulture/TurfgrassDiseaseIdentificationGuide.pdf
https://gardeningsolutions.ifas.ufl.edu/lawns/problems-and-solutions/large-patch/
https://gardeningsolutions.ifas.ufl.edu/lawns/problems-and-solutions/lawn-diseases/
by Dr. Leynar Leyton | Oct 24, 2024
The trend of having a clover lawn, or sometimes called a “fairy” lawn, has gained popularity in the last years. The trend has gained fame as homeowners are more conscientious about the environmental impact of their gardening decisions.
A turfgrass lawn usually requires many inputs to perform at it best: irrigation, fertilization, and regular maintenance (mowing, weed control, etc.). Let’s be clear, turfgrass lawns are not “bad” for the environment per se. In fact, they provide multiple benefits: they control erosion; help with water infiltration; prevent storm water run-off; they reduce noise; and they capture carbon (CO2) from the atmosphere. What gives turfgrass lawns a bad reputation is all the external inputs needed for them to look well maintained and aesthetically pleasing. That is why clover lawns have gained some popularity.
Clover – because of its growth habit – does not require constant mowing. It is also a legume, and as all legumes do, fixes nitrogen into the soil (we may say it produces its own nitrogen fertilizer). Plus, it will have all the other benefits of a turf lawn, or any other plant ground cover: erosion control, water infiltration, storm water control, noise reduction, and CO2 capture into the soil.
There is a superior legume (in my opinion) that can be used as a lawn alternative that unfortunately only grows in warm semi-tropical and tropical climates. But I have good news for you: If you are a Florida resident, you do live in a subtropical or tropical climate!
I am talking about Ornamental Rhizome Perennial Peanut.
Ornamental Rhizome Perennial Peanut. Photo by Dr. Leynar Leyton, UF/IFAS Ornamental Plant Breeder and Assistant Professor in Environmental Horticulture.
Ornamental Rhizome Perennial Peanut, it is a legume with far superior ornamental and growing habit characteristics than clover. You might be surprised by this statement, as you might heard – or seen- many bad examples of perennial peanut lawns, which give Ornamental Rhizome Perennial Peanut a bad reputation. First, we need to understand that not all peanut plants are the same. Perennial peanut it is not the same peanut that is used for peanut butter or boiled peanuts. Although both are members of the same genus (Arachis) they are different species. Annual peanut (the one that produces peanuts) is Arachis hypogaea. In contrast, perennial peanut does not produce peanuts, and it is a perennial plant (it does not have to be planted each year).
Perennial peanut can be either Arachis glabrata or Arachis pintoi. These two species may look similar, but they are very different. Arachis pintoi, sometimes referred as ‘Pinto peanut’ is a stoloniferous species, which means it produce ‘runners’. Arachis glabrata, in the other hand, produces rhizomes. Rhizomes are underground ‘root’ like structures that store ‘food’ (carbohydrates or starch). I am sure you have seen rhizomes before; some examples include ginger, bamboo, and mint. This is a key difference between Arachis pintoi and Arachis glabrata.
Rhizomes in rhizome perennial peanut (Arachis glabrata). Photo by Dr. Leynar Leyton, UF/IFAS Ornamental Plant Breeder and Assistant Professor in Environmental Horticulture.
The rhizomes of Arachis glabrata give it an outstanding characteristic: drought resistance. Once Arachis glabrata gets established, and the rhizomes have had time to store nutrients and starch, the plant can resist long periods of drought. This does not mean that the plants will look ‘perfect’ under long periods of drought, but that it will survive and come back after it gets water again. The stoloniferous types (Arachis pintoi) lack the drought resistance, although they can be somewhat drought tolerant, but they will tolerate some flood conditions.
Another important characteristic to look for in Ornamental Rhizome Perennial Peanut is the cultivar that you are buying. There are many forage types of rhizome perennial peanut, and you do not want those. Forage types are “taller”, between 6 to 18 inches tall, and were selected for their ability to produce biomass. Ornamental cultivars of rhizome perennial peanut are much smaller (less than 4 inches tall). That is why I have been intentionally calling it “Ornamental Rhizome Perennial Peanut”. That is the key to have a beautiful perennial peanut lawn: using a rhizome, ornamental type of perennial peanut. Rhizome Perennial Peanut performs better in full sun, and in well drained soils. In heavier soils, rhizome perennial peanut will grow at a lower rate. And rhizome perennial peanut already grows a bit slower for the liking of some people (let’s remember that rhizome perennial peanut plants are not only growing green leaves above ground, but also storing nutrients and starch into the rhizomes underground). In average, rhizome perennial peanut will grow about 6 inches per growing season with good growing conditions. This is an important consideration when you establish rhizome perennial peanut. Rhizome perennial peanut also produces beautiful orange flowers, that attract pollinators.
Ornamental Rhizome Perennial Peanut A. glabrata ‘Ecoturf’ in North Florida. Picture by Dr. Leynar Leyton, UF/IFAS Ornamental Plant Breeder and Assistant Professor in Environmental Horticulture.
One of the most popular cultivars of Ornamental Rhizome Perennial Peanut are ‘Ecoturf’, ‘Cowboy’, ‘Waxy Leaf’ and ‘Needlepoint’. You might see ‘Golden Glory’ sometimes described as a rhizome type, but it is not. ‘Golden Glory’ is a stoloniferous type (Arachis pintoi) and it does not perform well. Our UF/IFAS Ornamental Perennial Peanut Breeding Program will release some new varieties of Ornamental Rhizome Perennial Peanut soon, but I’ll tell you more about that in the upcoming months. Stay tuned!
