When most wildlife biologists talk of invasive species, it is usually of the animal variety. But as landowners, land managers and hunters we have a greater threat to our property and that is the invasive plants that seem to take over if left unattended.
Case in point – one of our neighbors is a large cattle farmer with roughly two thousand acres of cattle adjacent to our hunting property. For decades this was a great relationship, but as so often happens, one generation passes on and another assumes the responsibility of taking care of the property. The younger generation does not seem to take the same care of the property as his father did and the thistle is now rampant throughout his pastures. And as we all know, the seed of thistle is spread via the wind currents. Three years ago we did not see any thistle plants anywhere on our property, now, we have waged war against this plant with herbicides, and countless hours spot spraying in early spring to prevent it from spreading. However as we have learned, if we miss a single plant, thousands more emerge among the forest and plots seemingly overnight.
The other invasive species that we seem to deal the most with in the south is the sweetgum tree. This is the anathema of southern planters. This tree is a colony tree, meaning it sprouts new shoots off of running root systems. And I have personally documented growth of over twelve inches a week! This tree is without question the greatest threat to a well-manicured ecosystem in the southeast. In other areas of the country there are other invasive species. We also have the bicolor lespedeza once planted for turkey enhancement, this fast spreading plant has turned into a thick impenetrable barrier in many locals. And lastly in the south is the dreaded kudzu. Kudzu can and does spread like wildfire. This vine will consume everything in its path and make land virtually unusable.
Methods of ridding invasive species vary from use of strong herbicides, to prescribed fire. Usually a combination of both is best for total control. Plants such as thistle are difficult because of how they spread. The slightest breeze can carry seeds for miles. Whereas fennel, sweet gum and kudzu spread use other methods of spreading their plague.
Dr. Grant Woods offers this advice when dealing with invasive species. If the trees are established, use the “hack and squirt” technique. Scaring the tree with a hatchet and spraying a strong herbicide into the tree will kill it. For less established areas, mowing and spraying will certainly help. At our farm, we mow the sweet gum trees three times a year and spray. By mowing we are basically turning the tree into a bush when it re-sprouts. Two weeks later we spray a strong herbicide designed to kill brush such as 2-4-D. This herbicide kills the sweet gum but not the grasses. (lesson here – brush over 18” will not die only be stunted) which is why we mow, let them recover and then spray. It seems to take about three years of this to get the sweet gum under control. Dr. Woods offers a “growing season fire” to substantially set back the sweet gum. By burning the undergrowth in August or September, you are attacking the plant during its peak growing season and this offers the best chance of completely killing the trees. (As always, seek professional assistance when considering prescribed fires) Other species such as fennel, kudzu etc are best controlled with herbicides. Certified Wildlife biologists are great for assisting landowners with the information they need to select the proper herbicide and technique.
Regardless of the species, we are constantly battling these invasive species. It is truly an never ending battle to gain control of your property. However with good management practices it is possible to control these species. While we may not eradicate them from our landscape, we can certainly get them under control.
