Citrus canker has made its way to Escambia County and may be more widespread that we realize. This bacterial disease was first seen in Northwest Florida almost 10 years ago in Gulf Breeze. Given time and the ease of transmission of this disease, we are now seeing affected citrus trees in both the east and west portions of Escambia County.
This disease is specific to citrus with grapefruit, lemon, and lime being the most susceptible to infection. The disease can infect all above ground tissues and often enters through natural openings and wounds of leaves, stems, and fruit. If you find an infection early in an isolated area of the tree, you can prune out and double bag the affected tissue for disposal. Often times, the disease is noticed only after a considerable amount of tissue and fruit are affected making it difficult to keep the disease in check.
Since the bacteria is so easily transmitted through rain and wind, it is difficult to prevent movement during our frequent storm events. People can also spread the disease by movement of unregulated citrus trees, on equipment, and even on clothing.
Citrus canker lesions appear on both the upper and lower surfaces of the leaves. Photo by Beth Bolles, UF IFAS Extension Escambia County
Lower surface with citrus canker. Photo by Beth Bolles, UF IFAS Extension Escambia County
If you suspect a citrus in your landscape has canker, do not bring a sample to your Extension office for identification. Take a photo of plant symptoms of upper and lower leaves, fruits, and stems so that your local Extension educators can assist with identification. The University of Florida publication https://edis.ifas.ufl.edu/publication/PP323 has quality photos and descriptions of the different stages of citrus canker, along with photos of other citrus issues.
Stem lesions on grapefruit. Photo by Beth Bolles, UF IFAS Extension Escambia County.
The bad new for homeowners is that there is not a treatment to cure citrus canker. If the infection is small (a few leaves or a branch), it may be possible to remove and dispose of the material, following proper sanitation guidelines. Homeowners may also suppress a small infection on fruit by using copper-based fungicides, applied at appropriate intervals. These fungicides only protect plant tissue for a short time by acting as a barrier to infection. See this UF publication for timing of copper sprays for fruit.
Once susceptible citrus are heavily infected, trees will have fruit and leaf drop, along with general decline and dieback. At this stage of the disease, homeowners should strongly consider removing the tree. If it can be burned on site in accordance with local burn laws, that keeps the material contained and may reduce disease transmission. Otherwise, all material should be double bagged and sent to a landfill. Do not compost any material onsite or at local composting facilities. Be sure to follow disinfecting techniques outlined in the University of Florida publication https://edis.ifas.ufl.edu/publication/PP323 for tools, hands, and clothing.
Since management of citrus canker is so difficult, prevention is the best method to protect your tree. If you are considering a citrus, choose a more resistant selection outlined in the UF publication, Table 2. Always purchase a citrus from a certified nursery and follow state guidelines which prohibits all propagation of citrus, unless registered to do so.
The February Q&A on Growing Tomatoes offered valuable tips for the home gardener to be successful with tomatoes in 2022. Below are the reference materials related to specific questions that were asked.
Let’s start out with the panels favorite tomatoes including hybrids and heirlooms.
Evan: Supersweet 100, Sungold
Larry: Amelia, Brandywine, Cherokee Purple
Sam: Better Boy, Tasti Lee, Sweethearts
Matt: Mountain Magic, Mountain Rouge, Bella Rosa
Daniel: Black cherry and Big Beef
I’m thinking of trying hydroponic gardening on a few tomato plants this year. Do you think a 50/50 mix of perlite and vermiculite would be a good approach for a soil medium? I’d like to use 5-gallon buckets and keep maintenance to a minimum.
I have come to expect the unexpected when working in Extension. Photo credit: Libbie Johnson
Working in Extension has given me a lot of interesting opportunities. On the job, I’ve found myself leading kayak trips all over Florida, building a two-story bat house, and wearing a Mr. Peanut costume while talking about agriculture. But I never really imagined being featured on a home improvement reality TV show. Sure, I’ve watched my fair share of Extreme Makeover: Home Edition and Love it or List it, but those were just entertaining ways to pass the time and maybe get some ideas for my own house.
Then, a few months ago our office was contacted by the producers of a show called Flip My Florida Yard, to inform us they would be in Escambia County to film an episode of the show for the Discover Florida channel. As part of the effort, they’d need a local Extension agent to go on a site visit, help review the landscape design, and talk about Florida friendly landscaping principles on air. Based on my prior experience as a Florida Yards & Neighborhoods agent (and our horticulture agent being swamped with Master Gardener training), I got the reality TV job.
Florida-friendly landscapes use water and fertilizer appropriately, include wildlife-friendly vegetation, and reduce stormwater runoff. Photo credit: Carrie Stevenson, UF IFAS Extension
Part education and part entertainment, the show’s premise is similar to most home remodeling shows. A couple or family wishing to improve their current home shares their hopes with the remodelers, the homeowners are sent away for a day, and upon their return they are surprised with a brand-new look.
The twist with Flip My Florida Yard is that the landscapes in need of improvement are redesigned with Florida-friendly principles in mind. During each episode, Extension agents, IFAS researchers, and landscape designers are interviewed about concepts like using mulch and compost, proper irrigation, or “right plant, right place” choices based on soil type and sunlight availability. Last season, the crew was in Panama City to help a family restore their yard after damage from Hurricane Michael. For our Escambia County program, we will focus on appropriate fertilization, managing stormwater, protecting the waterfront, and providing wildlife habitat.
The “Flip My Florida Yard” program features Florida homeowners getting a Florida-friendly landscape renovation. The show is available online and through several streaming services.
In late December I was interviewed by the show’s producers, and we spent a full day renovating a local backyard. The challenging, steeply sloping backyard was given some really nice amenities, including a rain barrel, a seating area, and wildlife attractants. Our local episode should air in March or April. In the meantime, all the past episodes are available for viewing on the Discover Florida Channel. The channel can be accessed via a free online account, or through several streaming services like Roku, Apple TV, and Amazon Fire. Flip My Florida Yard is a creative partnership between the Department of Environmental Protection/Florida State Parks and the state level UF IFAS Extension Florida Friendly Landscaping Program, so even the commercial breaks cover environmentally friendly messages and scenic views of state parks. Check it out—you might get some helpful ideas or even become the next homeowner featured!
Fall is the season for leaf color changes on many plants, but we are often concerned when we see evergreen plants with brown leaves. Learn what is normal browning for evergreens and when to seek more help from UF IFAS Extension Escambia County.
There are some key practices that are necessary to make sure your trees and shrubs establish and thrive in your landscape. Learn a few pointers from UF IFAS Extension Escambia County to promote healthy establishment after correct plant installation. Learn about installing shrubs with the UF IFAS publication Establishing Shrubs in the Florida Landscape.
Tree dieback is a complex syndrome and slow developing. Dieback is essentially a process in which trees lose leaves and limbs. This usually occurs as a result of severe stress to the tree’s bark or root system, but could be a result of a declining life cycle.
It’s important to note that there is a significant balance between a tree’s root system and the number of leaves and limbs it can support. For example, if a tree loses part of its root system, possibly due to disease or lawn equipment damage, the tree will forfeit a portion of its leaves. Dieback doesn’t happen overnight, though. It’s a slow process, with larger trees taking much longer time for signs of stress to emerge. However, a large tree root system is very sensitive to damage, whereas a small tree will adapt quickly and is much more resilient to damage. So, what can be done to prevent dieback in trees?
First and foremost, trees, like all living things, have a natural life cycle. Regardless of how you care for your trees, dieback will occur. The most important management measure in extending the life of a tree is to protect the root system and bark.
With each passing year, a tree grows new bark in the rejuvenation process. The bark replacement process inevitably becomes more difficult as the tree gets older and in turn the tree is more and more susceptible to dieback. If the bark becomes damaged, especially later in the tree’s life cycle, then fungi and insects have a much greater chance to cause serious harm. Treating bark damage with a wound dressing to prevent decay is the recommended procedure.
Lichens come in many forms and are commonly blamed for the decline and death of trees and shrubs, however they do not cause harm. Credit. Sydney Park Brown and Joseph Sewards, UF/IFAS.
A common misconception is that epiphytes, such as lichens and Spanish moss, are tree diseases. Epiphytes are known as “air plants” and thrive in the Panhandle. They survive on moisture and nutrients in the atmosphere and are harmless to trees. However, a tree that becomes inundated with epiphytes may be an indicator of excessive soil moisture, which may lead to root rot.
Lawn weed killers can have detrimental effects to trees, even if the application seems to be from a safe distance. When using a weed killer near a tree’s root system, confirm on the label that the product is designed to kill green growth only. It can’t be overstated that excessively fertilizing an old tree will greatly accelerate the decline of the tree. Some may think this will stimulate a tree and extend its life, but instead it will do the opposite. Young trees can tolerate fertilizer applications, as they need crown growth. Older trees will simply become top heavy, and structural damage will likely occur.
Don’t forget, trees need space too. A mature tree forced to occupy a small space will simply not adapt. Be sure to have adequate spacing when planting younger trees and shrubs in the vicinity of older trees. Also, keep your trees pruned away from touching structures and utilities.
Tree dieback is a complex issue to manage. By following these measures, you can help extend the life of your trees and continue to have a picturesque landscape.
For more information on tree dieback, contact your local county extension office.
Please visit Florida Friendly Landscaping, http://fyn.ifas.ufl.edu/, for more information on maintaining your landscape.
For more general information on lichens, please see UF/IFAS EDIS document “Spanish Moss, Ball Moss and Lichens-Harmless Epiphytes” by Joe Sewards and Dr. Sydney Park Brown: https://edis.ifas.ufl.edu/pdffiles/EP/EP48500.pdf
UF/IFAS Extension is an Equal Opportunity Institution.
