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.
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 (email@example.com).
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 (www.EDDMapS.org) 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.
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.
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.
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.
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 (https://www.floridainvasives.org/sixrivers/). 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.
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 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.
To let everyone know how the battle against this invasive plant in the panhandle is going
To encourage everyone along the coast to keep searching, reporting, and removing it.
Can you actually eradicate an invasive species?
But… you must find and begin to manage it early. What many call Early Detection Rapid Response (EDRR) – and beach vitex is just that in the state of Florida.
For those not familiar with the plant, it is called beach vitex (Vitex rotundifolia). It is native to the Pacific coast of Asia, extending from North Korea to Australia. This suggest that it can tolerate cold weather, something that has kept many south Florida invasive species at bay in the Florida panhandle, but not this one.
It likes dry sandy soils and open sunny areas – our beaches are perfect. It begins with a taproot and forms runners that cross the surface of the sand in all directions, ALMOST 360°, but not quite. The runners are herbaceous at first and form blueish-green ovate shaped leaves and a cluster of beautiful lavender flowers in the spring and early summer. As the plant grows it becomes more woody and can form a shrub growing between three and four feet high. In the fall, after the cold fronts begin, the flowers become small gray seed pods. Each pod contains four seeds, and the plant can produce up to one million seeds/m2. These are viable for several months and can tolerate salt water for that period as well.
The plant may have been introduced as early as 1955 but was certainly here by the 1980s. During that period the state of South Carolina decide to try it in dune restoration after a series of strong hurricanes. That is when it raised its ugly head and let us know that it is not a plant we want on our coast.
It grows aggressively forming large monocultures within the dunes. It is allelopathic, meaning it releases chemical compounds that can cause the decline of plants around it, this would include our beloved sea oats. Being a taproot plant, not a fibrous one like the sea oat, the integrity of the dunes to protect from storms is weakened. Becoming a shrub, it can also shade the sand keeping other native plants from sprouting and could impact both the survival of sea turtle hatchings and the listed beach mice around the Gulf.
The plant was first reported to us in Pensacola around 2014 by a birding couple we know in Gulf Breeze, Florida. It was growing on Fair Point near their home. They told us they had it under control on their property but that it was most likely coming from Pensacola Beach on Santa Rosa Island – so, we took a look – and we found it.
Since that time, we have found it in other coastal counties along the Florida panhandle and are trying hard to (1) remove it as fast as we find it and (2) educate others so they can help.
We just completed our annual survey event we call HALLOWEED. We only surveyed Pensacola Beach and the portion of the Gulf Islands National Seashore called Naval Live Oaks in Gulf Breeze. Here are the results from the 2022 HALLOWEED…
12 volunteers worked between 2-4 hours logging 41 total hours last Friday.
We have updates on the Pensacola Beach Survey – Naval Live Oaks results coming soon!!
95 sites of beach vitex in the bay area
57 of those (60%) are on Pensacola Beach (surveyed)
25 (26%) are at Naval Live Oaks (will need to be updated)
6 (6%) are on Navarre Beach (were not surveyed)
3 (3%) are in Gulf Breeze (not surveyed)
2 (2%) are on Perdido Bay (not surveyed)
2 (2%) are on Perdido Key (not surveyed)
Of the 57 sites on Pensacola Beach…
30 (32% of the total; 52% of sites on Pensacola Beach) are on NE Pensacola Beach – north of Via DeLuna Drive – and east of Casino Beach
24 (25% of the total; 42% of sites on Pensacola Beach) are on SE Pensacola Beach
2 (2% of the total; 4% of sites on Pensacola Beach) are on NW Pensacola Beach
1 (1% of the total; 2% of the sites on Pensacola Beach) are on SW Pensacola Beach
All 3 sites on WEST Pensacola Beach are GREEN – have been removed and have not returned; no survey of the west end of the island was conducted today – but based on current log – there is no beach vitex on west end of Pensacola Beach.
Of the 54 sites on the east end –
34 (63%) are on private property
20 (21%) are on public lands
Of the private properties –
24 (71%) have been either completely removed or have been treated and in the process.
10 (29%) have not been removed or treated – it is not illegal to have beach vitex and is up to the homeowner whether they want to manage it or not.
Of the public lands –
15 (75%) have either been completely removed and have not returned; or have been treated.
5 (25%) have not been removed or treated – it is up to us to make this change – and we will next spring.
We do hope to get a survey of Perdido Key completed by the end of the year.
We are also planning another annual removal event we call WEED WRANGLE for early spring 2023. We will need volunteers help to do this. If interested in helping, contact Rick O’Connor (firstname.lastname@example.org; 850-475-5230 ext.1111).
As for the rest of the panhandle here are the records in EDDMapS as of October 2022.
Escambia County FL – 44 records
Santa Rosa County FL – 4 records
Okaloosa County FL – 31 records
Walton County FL – 0 records
Bay County FL – 0 records
Gulf County FL – 1 record
Franklin County FL – 4 records
Wakulla County FL – 0 records
Jefferson County FL – 0 records
We are SURE this is under reported and we need your help to update these records as well as remove these plants before we are out of the EDRR phase and eradication is no longer an option. Again, contact me (Rick O’Connor) at the contact above if you would like to help.
In the invasive species world, we talk of “Early Detection Rapid Response” (EDRR). These are invasive species that are currently not in our area, or are in very low numbers, but pose a potential threat. One of these is the Cuban treefrog.
As the name implies, Cuban treefrogs are from Cuba, and arrived in Florida around 1920 mostly likely in cargo ships. With the tropical climate of south Florida, the frogs did well and began to multiple and disperse north. At the beginning of 2022 there were 1,953 records of Cuban treefrogs in the U.S. Currently there are 2,462. There were few records in the Florida panhandle, now there 45 records from 11 of the 16 panhandle counties. They are spreading.
In the past many of the invasive species that invade south Florida could not tolerate our winters. That is changing, and we are seeing more here than we have in the past. We have had one off records of Cuban treefrogs from our area over the years but recently there were reports of possible breeding pairs in Panama City, reports from the Crestview area, the Pensacola area, and several from the Milton-Pace area. Just recently they were found at one of the county buildings in Escambia County, in downtown Pensacola, and now near Gulf Breeze. Again… they are coming.
How would you know one when you see it?
First, they are treefrogs. Treefrogs differ in have toe pads at the end of each toe. Second, the adult Cuban treefrogs are much larger than the natives. Most of our native treefrogs are no more than two inches in length. Cuban treefrogs can reach six inches. The juveniles can be distinguished by looking at their belly. The skeleton appears blue through the skin. The skin between the eyes is fused to the skull (will not slide if rubbed with your thumb), and their eyes are reddish in color.
What do I do if I see one?
First, report it to the national database EDDMapS (www.EDDMapS.org). Second, if you are willing, humanely euthanize it. The most humane way to do this is to numb the nervous system first. This can be done by rubbing oral gel in the stomach or cooling them in a cooler with ice. Then they can be frozen.
Why are they a problem?
By definition invasive species DO cause problems. In this case Cuban treefrogs they are known to consume native frogs, wiping them out of many areas in the state. Like most invasive species, they reproduce at high rates and have few predators. One story came from a USGS biologist in Louisiana. He received a call from the Audubon Zoo in New Orleans stating they had ordered palm trees from a south Florida nursery for one of their exhibits. After a couple of days, the caretakers noticed numerous frogs they had not seen before. The biologist had an idea of what they might be and drove over. When he arrived, he decided to check the electric panel by the male restroom – Cuban treefrogs are known to reside here and sometimes short circuit systems. He opened the panel to find 30 Cuban treefrogs inside. Game on. New Orleans now has Cuban treefrogs.
By the way, this is a common method of dispersal – hitchhiking on plants from south Florida to nurseries and stores in our neck of the woods. Our winters are milder than they once were, and they seem to be overwintering and breeding. So, game on for us here in the panhandle as well.
If you think you may have a Cuban treefrog contact your county extension office to verify identification before you try to remove them. We certainly do not want harmless native species to get caught up in this management effort. If you have any questions, contact your county extension office.