National Invasive Species Awareness Week (NISAW) is a national initiative where agencies and organizations provide information on invasive species issues to decision and policy makers. It can also be a time where we provide that information to the general public.
Invasive species are a global problem threatening biodiversity everywhere. Many create economic problems for the communities they invade, and management can be costly. The University of South Florida has estimated the cost to be around $21 billion a year in the U.S. alone. The most effective method of management is to detect the invader early and respond rapidly.
The Invasive Species Curve
Florida is certainly no stranger to invasive species. In fact, with our climate and international travel, we have some of the largest problems. The Burmese python is a well known, but we also have problems with lizards, frogs, snakes, fish, snails, insects, mussels, and a large variety of plants. The state is divided into 15 Cooperative Invasive Species Management Areas (CISMAs). Two of these – Six Rivers and the Apalachicola Regional Stewardship Alliance (ARSA) cover the panhandle. Members of these CISMAs (which includes UF IFAS Extension) conduct management and education projects on local invasive species within their areas and also have a EDRR list for that area. An EDRR list is the Early Detection Rapid Response – the ones to be on the look out for.
Over the next few days UF IFAS Extension Agents from across the panhandle will be posting articles about the larger threats in their counties. We will be posting these by county so that both decision makers and the general public will be able to see which species are of most concern in their region.
If you have questions about invasive species in your area, or how to manage them, you can contact your county extension office for help.
The definition of an invasive species used by the University of Florida IFAS has three parts.
It is not native to the area.
Was brought to the area by humans; either intentionally or accidentally.
Is causing an environmental or economic problem, or somehow lower the community’s quality of life.
Florida is famous for its invasive species problems. Actually, every state in the country is battling this issue. In 2005 the estimated economic cost of invasive species in the United States was $137 billion annually. Looking at the Invasive Species Curve (below) you can see the most effective method of managing is to prevent them from coming in the first place. Easier said than done. International travel and commerce by plane and boat enters Florida every day, who knows what these are bringing with them. There is the legal trade, illegal trade, and the accidental hitchhiker. Though there are efforts in each state trying to prevent invasive species from entering, they do enter. Once they have arrived, resource managers move into what we call Early Detection Rapid Response (EDRR) in hopes of eradicating the species but at the very least containing them. It is a constant battle.
The Invasive Species Curve
Though separated from the mainland, our barrier islands are not immune to this threat. Humans travel to and from our islands all year round; we live on many of them. With us comes non-native species we both intentionally and accidentally bring. Some of these become invasive and can threated the wildlife of our islands. The state is divided into 15 Cooperative Invasive Species Management Areas (CISMAs). The western panhandle is under the Six Rivers CISMA, the eastern panhandle is under the Apalachicola Regional Steward Alliance (ARSA). Both CISMAs have developed a EDRR list for their area. As a member of the Six Rivers CISMA, I helped developed ours and below are the species considered the biggest threats to our island wildlife.
Florida CISMAs
Beach vitex (Vitex rotundifolia)
Beach vitex is native to the Pacific coast of Asia and was intentionally brought to the United States as an ornamental/landscape plant. It does well in open sunny areas, dry soils, along the coast – perfect for barrier islands. In the 1980s it was used for dune restoration in the Carolinas and that is when its invasive nature was first seen. Like all invasive species, there are few predators and disease, and so reproductive success is high. The species multiples and spreads rapidly, basically uncontrolled. Beach vitex is allelopathic, meaning that it creates an environment that can kill nearby plants and thus take over that area; sea oats are one species this occurs with. Its impact on wildlife could include the loss of required habitat and food source. It appears to have already impacted sea turtle nesting in the Carolina’s, and that threat exist here as well. It could also impact the ecology of the listed beach mouse.
I was first made aware of the presence of this plant in the Pensacola area in 2013. It was discovered on the shoreline of a private property on the Gulf Breeze peninsula in Santa Rosa County. It was suspected to have come from nearby Santa Rosa Island. A survey of the Pensacola Beach area found 22 sites where the plant existed. One was quite large, covering about 70% of the property. The others were small individual plants. Some were part of a homeowner’s landscape; others were on public land. At the time, beach vitex was not listed as an invasive species in Florida. Today it is and has also been declared a state noxious weed. A database search indicates there are currently 118 records in the state of Florida found in six counties. Four of those counties are in the Florida panhandle and include Escambia, Santa Rosa, Okaloosa, and Franklin. More in-depth surveys of the coastal areas, and islands, of the remaining counties in the panhandle may find more records of the plant. There are active projects in the Escambia/Santa Rosa area to manage it.
This yard on Pensacola Beach has become over run by vitex.
Cogongrass (Imperata cylindrica)
Cogongrass is native to Central and South America. It was brought to the United States accidentally through the Port of Mobile. It quickly spread across the landscape covering much of south Alabama, northwest Florida, and Mississippi. It now can be found in most of Alabama, a large portion of Mississippi, much of Louisiana and Georgia, some of the Carolina’s, Tennessee, and Virginia, and in every county of Florida. It is not only listed as an invasive species in these states, but also as one of the nation’s worst noxious weeds. It quickly covers pastureland. Being serrated and having silica with the grass blades it is not palatable to livestock, you can lose good pastureland when this invades. In natural areas and private timberland, it quickly covers the understory where it burns too hot during prescribed burning efforts and creates a situation where the valuable management method cannot be used. It is not a good plant to have on your land.
In 2020 we were made aware the plant was growing on Perdido Key in Escambia County. We are not sure how it got there but most likely from landscaping equipment that was not cleaned after working an inland area where the plant was present – this is a common method of dispersing the plant. Currently there are 456 records along the coast of the Florida panhandle. 404 of these are on coastal beaches and 52 are on our barrier islands. 44 of the island records are on Santa Rosa/Okaloosa Island, 4 at St. Andrew’s State Park, 1 on Cape Sand Blas, and 1 on St. Vincent Island.
What impact this plant will have on barrier island wildlife is not fully understood. But we know that it has not been beneficial within inland habitats and the potential of having a negative impact is there. Locally we will begin to survey for exact locations on the islands in Escambia County in 2023 and begin a management plan for those, as well as education outreach to reduce potential sources.
Cogongrass shown here with seedheads – more typically seen in the spring. If you suspect you have cogongrass in or around your food plots please consult your UF/IFAS Extension Agent how control options.
Photo credit: Mark Mauldin
Giant Salvinia (Salvinia molesta)
This is a new invasive species to our area and, until recently, was only found within our state in the panhandle. There are now 19 records found in 7 counties across the state; 10 of the 19 records are in Escambia County. This is a freshwater species that prefers quiet backwaters with high levels of nutrients. In our county the plant is concentrated in the upper arms of Bayou Chico. Though an estuary, Bayou Chico has relatively lower salinities than most of our other bayous – the plant is doing well there. The Florida Fish and Wildlife Conservation Commission (FWC) began management of this area a few years ago, but it is still there and seems to have spread to a nearby retention pond. The best guess as to method of dispersal were beavers seen moving back and forth between the water bodies. We plan to conduct surveys of other nearby retention ponds in 2023.
Though relatively new to Florida, it has had a large impact on the freshwater systems of Texas and Louisiana. I witnessed firsthand that impact at a lake near Shreveport LA where I was camping. This plant is a small one that floats on the surface of the water. It resembles duckweed but the leaves are larger. It had completely covered the surface of the lake and was kept out of the swimming area by using booms. There was no way to fish in the lake and moving through with a paddle craft would have been difficult. It is similar to water hyacinth covered waters. Though the swimming area was clear, the bottom had become “mucky”, and no one was swimming. All water recreation had stopped. The thick canopy covering the surface of the lake blocks sunlight so no submerged grasses can grow, the dead plant material decomposes and draws down the dissolved oxygen levels which could create fish kills.
Knowing this, FWC has a team focused on eradicating this plant from our state before such situations occur here. Though it will not reach our barrier islands by floating there (because of its dislike of salt water) if it DID reach any of the retention ponds near the homes, hotels, and condos, via landscaping equipment used on inland ponds, or some other method, it could be a real problem. And, as we have seen in Bayou Chico, wildlife could move it to the natural freshwater ponds on the island. We will begin surveys of all ponds on Perdido Key and Santa Rosa Island in 2023.
Giant Salvinia mats completely covering Bay County pond. This fast growing invasive can double in coverage every two weeks! Photo by L. Scott Jackson
The Brown Anole (Anolis sageri)
This small lizard from Cuba (also known as the Cuban anole) has been in Florida for some time. It most likely reached our shores accidentally by hitchhiking on a boat. With south Florida’s tropical climate, the lizard did quite well and began to disperse north.
I first encountered the creature on campus in Gainesville. Along west side of Ben Hill Griffin Stadium (The Swamp) are trees that are enclosed in wooden boxes – a sort “raised bed” look. When I looked in one of them there were numerous brown lizards scattering everywhere. I checked the next tree and found the same. I found the same in each of the tree boxes along that road. I then began to see them at the rest stops on I-10 between Pensacola and Gainesville. You would step out of the car and as you walked you would see numerous small brown lizards scattering everywhere. The same ones as in Gainesville – the brown anole. I then received a call from a resident on Innerarity Point Road near Perdido Key. She wanted to know what type of lizard she was now seeing in her yard. They were small, brown, had white spots (diamond-like patterns) on their backs and were EVERYWHERE. I asked for a photo, and eventually made a site visit, they were the brown anole. I then began to receive calls from other residents near Perdido Key, then from Gulf Breeze, then from the East Hill area of Pensacola. All the same. The brown anole had made it to Pensacola. Interestingly, when I was speaking to a garden club about invasive species, and was discussing this one, residents from the north end of the county had no idea what I was talking about. They had never seen them. They apparently were invading near the coast. Between 2018-2021 I was conducting a cottonmouth survey on Perdido Key for a Homeowners Association who was encountering a lot of them. At first the brown anoles were not there. Then, during the second year of surveying, I began to see them. The brown anole had reached the barrier island.
It is believed that the mode of dispersal is the same as how they reached Florida in the first place – hitchhiking. Most likely on landscape plants that were grown in south Florida, transported up here, and delivered to you. It is not quite clear how they may impact barrier island wildlife. We know where they show up the native green anole (Anolis carolinensis) begins to decline. Some studies show that the green anoles move higher up in the trees and shrubs where needed resources are limited, and the population will most likely not survive. I have watched green and brown anoles battle it out on my front porch (yes – I have brown anoles in my yard also). I have seen green anoles win these battles – but they seem to have lost the war. I seldom find them anymore. What changes may happen to wildlife on the barrier islands we will learn with time. Though I have not personally seen one on Santa Rosa Island, I am sure they are there – and probably on your barrier island also.
Cuban Anole. Photo credit: Dr. Steve A. Johnson, University of Florida
Cuban Treefrog (Osteopilus septentrionalis)
As with the brown anole, it is believed the Cuban treefrog reached our state hitchhiking on a boat. They too have been in the state for quite some time. But records in the Florida panhandle were non-existent. It was believed that the winters here too cold for them. But that appears to be changing.
I have had occasional calls about this frog over the last few years. In each case it was a single individual, hanging on their windows and glass doors, shortly after the homeowner had purchased new plants for landscaping. As with the brown anole, we believe this is a common method for spreading them. But as we mentioned, there was not much concern because our cold winters would keep this invasion at bay. Then there was a report of several Cuban treefrogs at a location on Tyndall AFB in Panama City. They appeared to be breeding and also appeared that they had overwintered. Dr. Steve Johnson (of the University of Florida) later confirmed this to be the first recorded breeding group in the panhandle. And the “love had begun to spread”. More accounts were being reported in the western panhandle. One community in Santa Rosa County found over 100 over the course of a year. Again, we think they are spreading with landscaping plants, or hitchhiking by other methods.
The issue with the animal is similar to that of the brown anole. It is much larger than our native treefrogs and likes to devour them. They are large enough to eat small native lizards and snakes as well. They produce a mild toxin in their skin that can irritate your eyes, nose, and even trigger asthmatic attacks. They have been found in toilets and are known to even plug the plumbing. They have also been found in electrical power boxes and have caused power outages. Overall, they are pain to deal with.
There are currently 28 records in the Florida panhandle. Though some have been found along the coast of our estuaries, there have been no reports on our barrier islands. Maybe we can educate the public on the hitchhiking issue and possibly keep them off the islands. We will be initiating a citizen science effort to monitor their locations on Pensacola Beach and Perdido Key beginning in 2023.
Cuban Treefrog.
Photo by: Dr. Steve Johnson
Invasive species, by definition, are a problem for barrier island wildlife. But another problem they are facing is the increase in humans. That will be the topic in part 9.
Since entering the U.S. from Eastern Asia in the 1920s and especially since its promotion as the ultimate wildlife tree in the last few decades, I doubt there has been a more widely planted tree by outdoor enthusiasts than Sawtooth Oak (Quercus acutissima). It is easy to see the tree’s appeal. Sawtooth Oak grows quickly relative to other oaks, rates of 3-4’ per year in youth are not uncommon. It bears fruit at a very young age, as soon as five-seven years from seed, and produces a heavy crop almost every year, unlike many native oak species. Mature specimens are also mostly pest/disease free and very attractive, reaching 40-60’ in height with sweeping, wide-spreading branches, and deep, furrowed bark.
While it seems that I just described the ideal wildlife tree, and Sawtooth Oak can indeed be a worthy inclusion to your property, it is not perfect. All too often I see landowners and hunting lease holders plant solely Sawtooths as a part of their mast-producing tree strategy. As in other areas of life, avoiding monocultures and adding a little diversity to your wildlife tree portfolio is beneficial. Keep that, and the following lessons I’ve learned the hard way, in mind when you consider adding these wildlife attracting trees to your property.
20 year old Sawtooth Oak in Calhoun County, FL. Photo Courtesy of Daniel Leonard.Sawtooth Oak acorns. Photo courtesy of Daniel Leonard.
Acorns Drop Early – Sawtooth Oaks produce all their acorns very early in the season, beginning in September. Conversely, most of our native oaks drop their mast (a fancy word for tree fruit) during the winter months that comprise our main hunting season, November-January. So, while Sawtooth Oak is an excellent wildlife attractor and most any creature will readily gobble up their acorns, if you plant them to hunt around or provide a critical winter food source, you’ll likely be disappointed.
Invasive Potential – As Sawtooth Oak is non-native, very adapted to the Southeastern U.S. climate, and produces literal tons of acorns each year, the species has the potential to become a nuisance invasive. I’ve visited several sites over the last few years that had a couple of large Sawtooth Oaks planted in areas mostly excluded from wildlife pressure. I was surprised to see small Sawtooth saplings popping up everywhere. It was eerily reminiscent of other nuisance trees like Chinaberry and Camphor. Though I don’t think Sawtooth Oak will ever be a problem on the level of Chinese Tallow or Cogon Grass, it’s wise to use caution with plants that have invasive potential.
Less Nutritious Acorns – Sawtooth Oak acorns are heavily browsed, but it’s not necessarily because they’re extremely nutritious. A study from the 1960s compared the nutritional quality of Sawtooth Oak acorns to 8 common native oak species and found Sawtooth lagged the natives by a significant margin in all macronutrients measured: protein, fat, and carbohydrates. This finding suggests that, while Sawtooth Oak is an excellent wildlife attractor, if your goal is growing higher quality game animals and providing valuable nutrients to get them through the winter when wildlife forages are scarce, Sawtooth Oak should be a minor component of your strategy, not the endgame.
Longevity – The jury is still out on longevity. However, anecdotal evidence from around the Southeast suggests that Sawtooth may not be as long-lived as some of our native oaks. This could be due to several factors. First, as a rule, extremely fast-growing trees tend to be shorter lived due to weaker branching structure, less dense wood, and other factors. Think of the tortoise and the hare analogy. The quickest do not always win the race. Second, Sawtooth Oak did not hold up particularly well during Hurricane Michael and other strong storms. Their growth habit (heavy, wide spreading branches low to the ground) is not conducive to major wind resistance. This is to be expected as Sawtooth Oak is native to areas that do not experience tropical wind events and likely evolved accordingly.
I am by no means suggesting that you shouldn’t add Sawtooth Oak to your property in the hopes of encouraging wildlife. There are few trees available that do a better job of that. I am suggesting that Sawtooth Oak should be a small part of your larger overall planting strategy and you should keep in mind the potential drawbacks to the species. Plant mostly native oaks, allow Sawtooth Oak to be merely a supplement to them, and I think you’ll be pleased with the results! Putting all your acorns in one basket is rarely a good strategy.
For more information on Sawtooth Oak, other wildlife forage and attractant strategies, or any other natural resource, agronomic or horticultural topic, please reach out to your local UF/IFAS Extension Office!
First, the invasion seems to be silently spreading. A just a couple of years ago we had very few records, one off individuals that were removed by those reporting. But they have slowly, and quietly, been spreading. A couple of years ago there was a report of a small group of them near Tyndall AFB in Panama City. Dr. Steve Johnson, University of Florida, decided to see if this small group survived the winter, they did. It was confirmed as the first breeding population in the panhandle. Then the one off reports began increasing again.
Photo by: Dr. Steve Johnson
One area in Santa Rosa County was recording numerous individuals. These reports continued over the winter, and it seems they were breeding there as well. In my neck of the woods, Pensacola, I am getting more calls about them. EDDMapS currently list 18 records in the panhandle. This is definitely underreported. Most of those are in the Panama City area. The entire invasion reminds me of the Cuban (Brown) Anole; quietly increasing numbers while we watch and wonder what to do.
Second has to do with that issue… what to do. Managing invasive plants seems to be easier that invasive animals. People seem to be fine with pulling or spraying weeds. But euthanizing animals is another thing. And I get it, I like frogs too. Ending any life is hard to do. This makes managing this species much harder.
One way to look at next steps is to stop the introduction of any more species. We are pretty sure the primary method of introduction is what we call “hitchhiking”. Most of the plants we purchase for our landscaping projects come from large commercial nurseries in south Florida. Here they are grown by the hundreds of thousands, loading on trucks, and brought to our part of the state. Unbeknown to us, other small creatures are hitchhiking on these plants and their containers. Some of these are invasive species like the Cuban (Brown) Anole, and the Cuban Treefrog. At one time, this was not as much of a concern because they would not survive our cold winters. But our winters are not as cold anymore. Hard freezes do occur, and this may still be our best management plan, but with fewer hard freezes breeding populations will be allowed to continue the invasion. And it could be that with higher numbers of Cuban Treefrogs in the area, some will survive these freezes to continue. This has certainly happened with the Cuban (Brown) Anole.
Cuban Anole. Photo credit: Dr. Steve A. Johnson, University of Florida
So, I am not sure. The answer may be no to this one. One thing we can do is help monitor their populations. When we see a Cuban Treefrog report it to EDDMapS or your county extension office. This will give us a better idea of how the invasion is going and whether they are surviving our winters.
How do you know a Cuban Treefrog from our native species. Here are a couple of articles on how to do this.
If you choose to euthanize them, how do you do this humanely?
You can catch them using 3-foot sections of PVC pipe about 1.25” in diameter. These are placed vertically in the ground along the outside wall of a building near an exterior light source (where bugs are attracted). In the morning, check the inside of the pipes. If treefrogs are present, try to identify them. Cuban Treefrogs are the only ones in the panhandle that reach lengths of 4-6 inches. If they are all small, you will need to collect them and identify them using one of the publications listed above.
If you positively identify one, the first step is to confirm it. You can do this by contacting your county extension office. Second, report it to EDDMapS (www.EDDMapS.org). If confirmed, and you choose to euthanize it, the following link will explain how to do this humanely.
This situation is similar to the lionfish invasion we experienced 10 years ago. We know they are here, and we know they can be a serious problem. We are not sure we can eradicate them, but they should be managed. We will see how this goes.
Based on the number of EDDMapS records for the panhandle – yes… we can.
And if these records are accurate – yes… we should.
I have seen the impact this plant can make. It has invaded Texas and Louisiana and has caused enough problems for the USDA to list it as one of America’s most noxious weeds. In Texas they have had “all calls” for anyone able to come to the state and help with management.
Giant Salvinia mats completely covering Bay County pond. This fast growing invasive can double in coverage every two weeks! Photo by L. Scott Jackson
I was camping in a state park near Shreveport LA. After we set up camp my grandson and I went to look at the lake. You could tell it was once clear water and cypress trees, but the water was completely covered with plant growth that looked, from a distance, like dollar weed and that there was no visible water at all. Completely covered. And then it hit me… THIS IS SALVINIA! Shortly after I saw the sign along the shoreline describing the plant and what to do to avoid spreading it. There was a yellow boom stretched across the surfacce to keep the plant from getting into the swimming area – but no one was swimming. The bottom was muck and I did not see any fish. There was no recreational activity at all. The boat ramp was completely choked with the weed, and I am not sure you could paddle through it anyway. It was a mess.
According to EDDMaps, there are only 14 records statewide, 11 of those are in the panhandle, and 9 of those are in Pensacola. We are certainly ground zero for the problem and FWC has been working over the last couple of years to eradicate it. All nine records are in Bayou Chico, and if FWC is successful at eradicating it, this will significantly make strides to eliminating the plant from the state. The other two locations in the panhandle are a retention pond at the northern arm of Deer Point Lake in Bay County, and a pond near Quincy FL.
Is this all of it?
Are there other sites with this plant that we do not know about?
I have been following EDDMapS records for a couple of years now and there are new records in central and south Florida -so, maybe.
If so, they need to be reported so that FWC can begin treatment. How would you know if the plant is present? How do you identify it?
Here are links to learn more about the plant. It prefers quiet/slow moving freshwater systems with plenty of nutrients. If you think the plant is present in your community, contact your county extension office to verify and report it.
Most of us have heard of invasive cogongrass (Imperata cylindrica). It arrived in the early part of the of the 20th century near Mobile Alabama and has spread across the lower southeast. It is an aggressive growing grass with serrated leaves and silica imbedded in its tissue. This makes it very undesirable for livestock and a threat to pastureland across the region – though there are reports of wild hogs consuming it. It can also invade timberlands where it burns hot during prescribed fires to a point where it can kill the trees you are trying to manage. It is considered one of America’s worst noxious weeds.
A relatively new patch of cogongrass recently found in Washington County.
Photo Credit: Mark Mauldin
The abundance of this grass across the uplands of the Florida panhandle would indicate that it is far too established for eradication to occur. But what about the barrier islands? Is it a threat there and, if so, can it be eradicated?
I personally have seen the plant growing on Perdido Key in western Escambia County. I know of two locations where it currently resides. One is on public land, the other private, but we have not conducted a proper survey of the distribution on the Key at this point. Something we plan to do in 2023.
I also know it is found along Highway 98 at Gulf Islands Naval Live Oaks near Gulf Breeze in Santa Rosa County. I am not sure how many records the National Park has of the plant, or how widespread it is on the Gulf Breeze peninsula, nor do I know if it is on Santa Rosa Island/Pensacola Beach. Again, surveys are planned for 2023. We obviously need to know this before we can answer the question.
As of Nov 27, 2022 – there are 82,106 records of cogongrass in the U.S. – all are in the lower southeastern portion of the country. There are records as far north as North Carolina and as far west as the LA/TX line. Alabama is completely covered, as is much of the Florida panhandle.
As far as barrier islands, it is found on each of those within the state of Mississippi (10 records total). There are eight records on Dauphin Island AL, 16 on Ft. Morgan peninsula, eight in Gulf Shores AL proper, and nine in the Orange Beach AL area.
In Florida there are five records on Perdido Key proper, 13 more along the north shore of Big Lagoon, 125 along coastal NAS Pensacola, seven at Ft. Pickens on Santa Rosa Island in Escambia County, seven more at Naval Live Oaks in Gulf Breeze, six on Eglin property on Santa Rosa/Okaloosa Island, and 32 on Okaloosa Island between Ft. Walton and Destin. Here the western panhandle islands end. Between Perdido Key, Santa Rosa, and Okaloosa Islands proper – there are 50 records of the grass.
Along the coast between Okaloosa Island and Shell Island in Bay County, there are 44 records. There are no records on Shell Island itself but there are 86 records on Tyndall AFB. There is one record on Cape San Blas in Gulf County, one on St. Vincent Island and another along Highway 98 just west of Apalachicola in Franklin County. The barrier islands between Apalachicola and Bald Point have no records.
Based on this, the islands at the far eastern end of the panhandle should easily be able to eradicate these plants. The islands on the western end have more work to do, but a total of 50 records ON THE ISLANDS should be doable. This, of course, is based on the number of records being accurate, and I am sure they are under reported.
Step 1 – conduct surveys.
As with beach vitex, the first step is to accurately survey our islands to determine how widespread the problem really is, and then develop a management plan to possibly eradicate them.
Step – management
There are currently no known biological controls for this invasive plant.
Repeated disking and deep plowing have been shown to be effective in agricultural lands where it is possible to do. Mowing and/or burning when not in seed AND THEN CHEMICAL treatment has also had success. This should be done in the fall. Mechanical management alone has not been effective.
The chemical active ingredients of choice are glyphosate and/or imazapyr. As mentioned in the beach vitex article, imazapyr has a much longer soil activity and replanting cannot be achieved for several months. Replanting with native plants has been found to help control cogongrass but to do so quickly would require the use of glyphosate. In all studies, one chemical treatment was not enough.
This is a very tough noxious weed and early detection – rapid response (EDRR) is crucial at eradicating this species. We will begin Step 1 in Escambia County this year. If there are groups in other counties interested in doing the same, let us know and we will help where we can (roc1@ufl.edu).
