Can We Eradicate Cogongrass from the Panhandle Barrier Islands?

Can We Eradicate Cogongrass from the Panhandle Barrier Islands?

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 (   

Assessing the Status of Diamondback Terrapins in the Florida Panhandle 2022 Update

Assessing the Status of Diamondback Terrapins in the Florida Panhandle 2022 Update


The diamondback terrapin (Malaclemys terrapin) is the only resident brackish water turtle in the United States.  Ranging from Massachusetts to Texas.  This estuarine turtle spends much of its time in coastal wetlands such as marshes and mangroves but have been found in seagrasses.  They feed primarily on bivalves, have strong site fidelity, and live to be 20-25 years in the wild.  Studies on their basic biology and ecology have been published throughout their range with the exception of the Florida panhandle. 

In 2005 the Marine Science Academy at Washington High School (MSA) was asked to survey coastal estuaries within the Florida panhandle to determine whether diamondback terrapins (Malaclemys terrapin) existed there. 

Methods – Presence/Absence

To determine presence/absence MSA identified boat ramps near suitable terrapin habitat.  “Wanted” signs were placed at these ramps with our contact information and beach walk surveys were conducted seeking terrapins or terrapin sign.  Since the best time to conduct beach surveys is May and June (not suitable for high school), that part of the project moved to program director and his family. 

Surveys were conducted and terrapins were found in each of the six counties between the Alabama state line and the Apalachicola River. 

Methods – Relative Abundance

The next question was to assess their relative abundance.  To do this the team followed a protocol used by Tom Mann with the Mississippi Department of Natural Resources we call the “Mann-Method”.  There are recognized assumptions with this method.    

  1. Every sexually mature female within the population nests each season.
  2. Each female will lay more than one clutch per season but never more than one in a 16-day period. 
  3. You know where all nesting beaches are located.
  4. The sex ratio to males is 1:1. 

Going on these assumptions, every track, nest, or depredated nest on the nesting beach within a 16-day window is equivalent to one female.  If the sex ratio is 1:1, then each female is equivalent to one male, and you have a relative abundance of the population.  That said, there are publications suggesting the female: male ratio could be 1:3 or even 1:5 in the Florida panhandle.  We would report the relative abundance as 1:1 – 1:5 for each nesting site.

Another method of estimating relative abundance is conducting a 30-minute head count.  From a fixed location, or drifting in a kayak across the lagoon, every head spotted in a 30-minute period is logged.  The assumption here is that if the average number of heads / 30-minutes increase or decreases over time, the relative abundance within the population is increasing or decreasing as well. 

Trained volunteers conducted these surveys at least once a week at each nesting beach from April 1 to June 30 each year. 

2022 Data Update

  • 47 volunteers were trained in March of 2022; 21 (45%) participated in surveys. 
  • 173 surveys were conducted; 346 hours were logged.
  • Terrapins (or terrapin sign) were encountered during 43 of the surveys – Frequency of Encounters = 25% of the surveys. 
  • Surveys occurred in Escambia, Santa Rosa, Okaloosa, and Bay counties.  Encounters occurred in all counties except Bay. 

Beach Surveys – 2022

County# of Surveys# of EncountersFrequency of Encounters
Santa Rosa5815.26

Head Count Surveys – 2022

County# of SurveysRange of Heads/30-minMean of Heads/30 min
Santa Rosa20-4924

Estimated Relative Abundance Using the Mann-Method

CountyNesting Beach SurveyedRatio 1:1Ratio 1:3Ratio 1:5Relative Abundance for the County
Escambia148124-12 terrapins
Santa Rosa11224362-48 terrapins
Okaloosa12448722-72 terrapins
YearCountyRelative Abundance
2008Santa Rosa14-35
2009Santa Rosa14-35
2010Santa Rosa32-80
2011Santa Rosa10-50
2015Santa Rosa12-30
2018Santa Rosa16-40
2021Santa Rosa4-12
2022Santa Rosa2-48

Terrapins Captured – tagged – and tissue samples collected

County# of Terrapins Captured/Tagged/Tissue Collected
Santa Rosa2


At the beginning of this project Objective 1 was to determine whether diamondback terrapins existed in the Florida panhandle.  That objective has been met – they do, we have at least one verified record in all six counties between the Alabama state line and the Apalachicola River. 

Objective 2 is to determine the relative abundance within these counties.  The first step in addressing this objective is to determine where terrapins are nesting in each.  Nesting beaches have been identified in Escambia, Santa Rosa, and Okaloosa counties – but we are not sure whether ALL of the nesting beaches in those counties have been identified. 

Known nesting beaches in Escambia County have changed over time.  Two of the three nesting locations have become inactive in recent years and other potential beaches have not been adequately surveyed to determine whether they are being used or not.  Based on one active nesting beach, the relative abundance of terrapins in Escambia County is low.  Estimations using the Mann-Method suggest that there are between 2-24 terrapins present. 

There are numerous potential nesting locations in Santa Rosa County but only a few have been adequately surveyed.  Currently there two active nesting beaches being surveyed and the relative abundance at these has run between 30-80 animals at one location, 6-36 at the other.  Going with this, there are between 6-80 terrapins present. 

Okaloosa has only recently been surveyed.  There are currently three active nesting beaches being surveyed and most of the nesting is occurring at one of those.  The location of these beaches suggests that these are all animals of the same group or clad and part of the same population.  Based on the results there are between 2-72 terrapins present. 

Surveys are JUST getting underway in Bay County and no surveys have been conducted in Walton. 

These data suggest that the relative abundance in each county is less than 100 and small when compared to other locations within their range. 


The results are only as good as the data being used.  The volunteers participating in this project are doing an excellent job, but the frequency of nesting beach visits and head counts surveys are lower than needed to make accurate assessments.  Several of the nesting beaches are in difficult places for volunteers to reach frequently and thus not surveyed as frequently as we would need.  More volunteer participation could help this.  Keep in mind that the Mann-Method also focuses on nesting females and males, immature females are not accounted for so the population would be slightly larger than estimated using this method.  That said, we do believe that the populations in this part of their range are most likely smaller than other parts of their range.  These surveys will continue.  Questions or comments can be directed to Rick O’Connor, Florida Sea Grant, University of Florida IFAS Extension,

Can We Eradicate the Invasive Beach Vitex?

Can We Eradicate the Invasive Beach Vitex?

If you read the introduction article to this series you would know that yes – based on comments from Dr. Simberloff, we can.  But your best chance at doing so is when the species is early in its invasion of the area – Early Detection Rapid Response (EDRR).  This can be seen again on the invasive species curve (pictured below). 

Have we jumped on the beach vitex issue quick enough? 

I am not sure.  Based on the records provided to EDDMapS ( there are 677 records in the United States.  97 of those are in Florida.  80 are in the Florida panhandle with another 5 records in Baldwin County AL.  44 of those records are in the Pensacola Bay area, another 34 in the Choctawhatchee Bay, and 5 records near Apalachicola.  This certainly sounds doable.  There are not that many records, and we should be able to easily remove plants from 80 sites.  However, I am also certain this is much underreported.  In my spreadsheet from our local surveys in the Pensacola Bay area I have 97 records – over double what EDDMapS has reported – and you could assume the same for the others. 

From EDDMapS, in the Pensacola Bay area there are three records from Perdido Bay, one from NAS Pensacola, 18 from Pensacola Beach, 3 from Navarre Beach, and 22 from Gulf Islands National Seashore.  Within Gulf Islands 20 of these are from Naval Live Oaks, 1 from Ft. Pickens, and 1 from Opal Beach. 

From my survey records I have 3 records from Gulf Breeze, 2 from Perdido Bay, 2 from Perdido Key, 7 from Navarre, 26 from Gulfs Islands National Seashore, and 57 from Pensacola Beach.  I should add here that 1 of the 3 in Gulf Breeze, 1 of the 2 in Perdido Bay, and 25 of the 57 on Pensacola Beach are currently “green” on my spreadsheet indicating that have been treated, removed, and have not returned (“eradicated”) – that is 28% of the known records – 70 records (72%) are still out there. 

When you look at the Choctawhatchee Bay area, 32 of the 34 records are on Eglin AFB property and are being controlled.  I am not sure how many have been eradicated, but they know where they are and are on top of the problem.  Two additional records are in Okaloosa County proper, one on Hwy 98 between Ft. Walton and Destin, the other in Henderson State Park near Destin.  Likewise, I am not sure of the status of these two sites.  Further east there is a record in Gulf County, and four in Franklin County.

These numbers suggest that yes… we have jumped on this plant soon enough and that eradication is possible.  But… do we have all of the records?  Are there really only these in the counties reported?  Are there no plants in Walton and Bay counties?  One would feel that there are more out there. 

Vitex beginning to take over bike path on Pensacola Beach. Photo credit: Rick O’Connor

Step 1 – we need GOOD surveys conducted. 

To date, all of the records have been coastal along the Intracoastal Waterway.  The seeds are viable in saltwater for up to six months.  Any seed that makes into the ICWW can easily be dispersed to new locations.  But it will take diligent work from community partners to survey these areas and update all of the records.  If interested in doing a survey, let me know. 

Step 2 – treatment. 

When treating invasive plants there are three methods you can choose.  (1) biological, (2) mechanical, and (3) chemical.  Currently, there are no biological controls for beach vitex approved by the Department of Agriculture, and I am not aware of any studies testing one.  So… this is not an option at the moment.  Many prefer not to use herbicides and that means mechanical removal.  There are plenty of records in the Pensacola Beach area where this has been successful.  In each case the plants where young, herbaceous vines and we could easily pull the taproot out.  In some cases, we did have to dig to remove all of the plant, but – based on annual surveys after treatment – they have not returned.  But in many cases mechanical removal was not an option due to the depth of the taproot, the extent of secondary roots extending from the spreading stolons, or the sheer mass and area in which the plant had invaded.  As beach vitex grows it becomes woodier, and more of a shrub with extending vines running in all directions.  At this stage you will need chemical. 

Based on studies conducted at Clemson University, the most effective chemical herbicides are those with the active ingredient IMAZAPYR.  This chemical showed success within one year in many cases but has its problems.  (1) The chemical is non-select, many it will kill any plant it comes in contact with – and they could be very undesirable.  (2) it has a long soil activity life – meaning it is active in the soil for several months.  Nothing will grow in the location and re-planting with native plants could be unsuccessful.  TRICLOPYR is a chemical used for Chinese Tallow and Poison Ivy.  It seems to be very effective on beach vitex however, it too is non-select and though its soil activity is not as long as imazapyr, there is a period of time when re-planting will not be successful.  A third chemical tested was GLYPHOSATE.  This product is also non-selective but its soil activity is only a few days, allowing from re-planting within a week.  However, because it is not as effective as the previous chemicals, re-treatments each year may be required (one study suggested up to five years of re-treatment may be needed). 

The chemical we are currently using is glyphosate.  Though it does mean that many of our records have not been eradicated yet, we can re-plant with native plants very soon and this has been desirable for a variety of reasons.  You must be careful to reduce over spray so that you do not kill neighboring plants.  In most cases, we remove all of the above ground biomass and then cut and treat the taproot.  Returning the following year to see how it has done.  NOTE: the seeds are numerous and working with the plant while it is in seed could spread the problem.  It is in seed during the fall and winter.  We recommend waiting until spring to do removals and summer to do chemical treatments. 

Step 3 – monitoring. 

It is important to re-visit each site (even it has been gone for over a year) to assess the status of these plants.  I am not sure how long seeds can be active in the soil.  There is a chance that though the plant you were working on was eradicated, the seeds it left the season before may sprout and re-treatment needed. 

YES – it is a lot of work, a lot of time, a lot of resources to manage invasive species.  Here again, finding the problems early and putting together a management plan can make the possibility of eradication possible and at a lower price.  Based on EDDMapS, there are four other records in the Jacksonville area.  If this is truly all there is out there, then we can – and should – eradicate this plant from the state.  But…

Let’s start with step 1 and go from there. 

If your community is interested in forming a survey/management team and needs help doing so, let me know.  We will do everything we can to make it effective and hopefully remove this plant from our area. 

Can We Eradicate Invasive Species?

Can We Eradicate Invasive Species?

I recently attended an invasive species conference, and this topic came up.  It seems strange that it would but those who work in the invasive species world have this in the back of our heads a lot.  I mean in a lot of cases we do not bring the word up when making presentations, what some call “the E word”, because we feel in the back of our heads, we will never eradicate them, and we should not lead people on that we might.  Lionfish management is a good example.  Everyone is aware that eradication is probably not an option and so we refrain from using the term when discussing this species. 

Lionfish in tank. Photo credit: Laura Tiu

It came back a few years ago when I began working with beach vitex on Pensacola Beach.  It was a relatively new species on the radar in Florida and was not even listed as an invasive species in our state.  When we first heard about it in the Pensacola area, I checked EDDMapS to see how many records there were.  There was a total of three statewide; two in the Jacksonville area and one in Pensacola.  I conducted surveys of Pensacola Beach and found 22 additional sites where the plant existed and thought – MAYBE… if this truly ALL there was – we MIGHT eradicate this plant from the Florida panhandle.  There was a point after we had treated and removed the plants from those sites that we MIGHT have actually… dare I say it… eradicated beach vitex from Pensacola Beach.  I felt pretty good about stating this and there was even a little ceremony at a meeting to celebrated it.  Then… we found some on the north side of the Intracoastal Waterway in Gulf Breeze.  Then the plant popped in Navarre.  Then Perdido Key.  Then in Apalachicola.  And after a few years, the plant popped up again on Pensacola Beach.  We were too quick to use the term eradication and – like so many who try to manage these species – have refrained from using the term ever since. 

As I watched what was happening with beach vitex, watching what was happening with the brown anole, Chinese tallow, and what I saw in south Florida with Brazilian Pepper, I could see why many felt eradication is not part of the program.  I could see why most would immediately go into management mode and just skip the idea of eradication.  I could see why many would toss in the towel and find something else to work on. 

This yard on Pensacola Beach has become over run by vitex.

On the second day of the three-day conference the keynote speaker was Dr. Dan Simberloff.  Dr. Simberloff has been working with invasive species management since the late 1960s.  His talk was entitled Managing Invasions: What’s Worked, What Hasn’t, and What Might.  Early in his talk he asked a question… “What is our ultimate goal?”.  There was silence in the room for almost a minute.  Everyone was pondering.  In my head I was thinking “to control the species distribution as best we could and stop the introduction of anymore”.  But that was not the answer he was looking for.  After about a minute (because NO one responded 😊) he said – “our ultimate goal is eradication”. 

Again, there was silence.  He used the “E” word – out loud – in front of everyone.  I am guessing others were thinking what I was thinking.  “I didn’t think eradication was really possible?”  But his argument was that it is possible and began to run down a list of situations where it in fact HAS happened.  He also discussed new technologies that COULD allow for more. 

It was good to hear this honestly.  It felt like a locker room pep talk at half time and you are down by two touchdowns.  Your thought is that the other team has this in the box, and we should play for another half but really be thinking about how we are going to improve for the next game, so we are not in this situation.  Then “Coach Simberloff” gives his locker room talk, you go back on the field, and things turn around – you come from behind and win the game.  He made us feel like it was possible.  That we are out their fighting now but not to lose focus of the ultimate goal. 

I began to think about the beach vitex situation in the Florida panhandle again.  Maybe… just maybe…

But here’s the deal.  If you look at the invasive species curve (image provided here) you will see that your best chance at eradicating an invasive species is early in the invasion.  What people have termed EARLY DETECTION – RAPID RESPONSE (EDRR).  In my head, I think we MAY be there with beach vitex.  I do not feel the populations in the panhandle are beyond the level that eradication may now be actually achievable.  IF we know where all of the plants are.  In the back of my head, I still wonder if we have missed more than there is and that the populations may be further up the curve than we think.  BUT let’s look at this way – maybe we DO know where most of those plants are. 

The state is divided into regional management areas (CISMAS) and the western panhandle is part of the Six Rivers CISMA.  During the COVID period of 2020-2021, we developed a EDRR list for this CISMA and it is posted on our webpage (  Being a Sea Grant Extension Agent, my focus is on the coast.  The barrier islands and the waters that surround them.  We do have a few EDRR species that are popping up on, and around, our islands.  Have we detected them soon enough?  I am not sure but over the next few weeks I am going to post articles here to discuss some of them in hopes that the public will assist us in finding, reporting, and managing them.  The ultimate goal is eradication.  Let’s see if we can pull this off. 

Dealing with the Armadillo

Dealing with the Armadillo

Florida has a love-hate relationship with this animal.  Some find them cute and adorable, others find them a pest and a nuisance, either way there is no ignoring this guy.  They are everywhere and yes – they can make a mess of your lawn and garden.  So, for those who are not so in love with the creature – what can be done? 

Let’s first meet the animal. 

There are about 20 species of armadillo found in Central and South America but there is only one in the U.S., the Nine-Banded Armadillo (Dasypus novemcinctus).  The Nine-Banded Armadillo is originally from South America and there were several different species of armadillos that made the trek from South to North America prior to the ice age.  But after the ice age it seemed no armadillos were present in the U.S.  After the ice age, the Nine-Banded Armadillo expanded north into Mexico, but it seems could not cross the Rio Grande.  That is until Americans began to settle the area.  Prior to American settlement, armadillos were hunted for food, and the land on both sides of the river was regularly burned.  The American settlers ceased the burning and the Native Americans declined in numbers, so hunting pressure declined as well.  Many armadillos were probably brought across intentionally, but others who managed to swim across, and armadillos can swim, now found suitable habitat with the decreased burning.  They had arrived and began expanding both east and west across the southern U.S.  However, the Mississippi River presented another barrier they could not deal with. 

The common nine banded armadillo scurrying across the lawn. Photo: Les Harrison

The introduction in Florida was a different story.  Apparently in the 1920s and 30s they were released by humans.  One release appeared to be an escape from a small zoo.  Another was from a circus.  There are reports of armadillos riding cattle cars on trains from the west and this allowed them to cross the Mississippi.  In the 1920s bridges were built across the river for a new invention called the automobile.  All of this led to the invasion and the animals are now here, they are also expanding north. 

Armadillos like warm/wet climates.  They prefer forested areas or grasslands and, again, can swim small rivers and creeks easily.  It has been reported they can hold their breath up to six minutes and have been seen literally walking along creek bottoms. 

They feed primarily on a variety of small invertebrates such as grubs, snails, beetles, and even cockroaches (many of you will like that).  They like to feed in wet areas or loose sandy soils where digging is easier.  Unfortunately, your lawn is a good place to hunt.  They rarely, but do, feed on small reptiles and amphibians and eggs. 

They breed in the summer but delay egg implantation so that birth is in the spring.  They typically give birth to quadruplets.  The armor of the young is not hard at first but hardens over time and does provide protection from large predators like panthers, bears, and alligators.  They typically live 12-15 years, but some have reached the age of 20. 

So… now you know the animal… for those who do not want them, what can be done?

Based on an article from UF IFAS Extension, not a lot.  Typical methods of deterring wildlife have not worked.  Poisons, smells, and even using firearms has not relieved the homeowner of the problem.  One study looked at trapping and found that in general it is hard to get them to enter.  In this study they caught one armadillo every 132 trap nights – low percentages.  Another study looked at baits and found crickets and worms worked best, but the smell of other armadillos in the trap also lured them.  One colleague mentioned the need for solid wood traps and he baits them with nothing but the shells of roadkill as had good success.  He mentioned the designs of these wooden traps are online.  You can get plans to build them, and you can also purchase pre-made ones.  Once captured they can be relocated but the trapper should be aware that armadillos have many peg-like teeth and very sharp claws for digging.  HANDLE WITH CARE.  It is also known that armadillos can carry leprosy, though cases of leprosy being transmitted to humans are rare.  None the less, handle with care. 

For more information on this animal, contact your county extension office.