Introduction to Managing Non-Native Invasive Species

As I spend time on the farms I hunt, I look around at the continuous battle of controlling non-native invasive species and the work still to be done, I have come a long way from where I started on the “home farm,” but every one of them removed is a step in the right direction. It can be frustrating especially when walking a new farm with a client to see the native species struggling with being over-taken by non-natives that provide next to nothing in terms of return of investment. But first let’s talk about what is considered and invasive species.

Considered to be damaging to the habitat of the land, invasive species are non-native to the original landscape that once covered the land. Do some research on native species to your area in the early to mid-1800’s, and you will probably be fascinated by the natural landscape that it once was. Before the European settlement that saw drastic changes, most of Iowa was full of prairie grass and wildflowers that played a very important role in the wildlife ecosystem. During the European settlement, many plant species native to parts of eastern and western Europe were brought over for either medicinal, agricultural or ornamental purposes and quickly began to be planted by the settlers in those areas. It did not take long for some of these plants to begin taking over parts of the native landscape drastically changing the habitat.  A common theme in modern society today is using flowering non-native plant species in residential and commercial landscape setting which has also created further issues for invasive species in our native habitat.

Native Iowa prairie landscape

During the late stages of spring through the early stages of fall many of us our setting up or checking trail cameras on our farms to begin the anticipation of the upcoming deer seasons, and I am right along with you. If you have the means and extra time, I recommend adding a couple extra “tools” to go along with your SD Cards and new batteries. Herbicide, a shovel, and a way to identify. Almost all the invasive species that I have come across, I had to begin by identifying what they are and if they are good for the wildlife and ecosystem on the farm or not. Many extension offices offer weed identification booklets, or if you are tech-savvy and want the quick answer there are many apps out there today that can identify the species of the plant with a simple picture of the leaves and flower or berry if produced.

Canadian Thistle

It is important once identified, to determine the correct course of action to begin eradicating the unwanted guest from your farm. Crown vetch for example, can be killed by application of glyphosate and 2 4-D Anime (low volatility) and continuous mowing if re-sprout occurs, while the Canada thistle is best controlled by digging up the root system and removing the plant from the farm for later burning in a controlled environment. I stress the importance of knowing the correct mode of action for removal to save a lot of time and money in the long run. For example if you had an area infested with thistle’s in early spring you can spray the newly germinating plant with glyphosate and it may have limited effect on the root system, but if you catch them in early fall the herbicide movement will actually be greater through the root system (this is of course you choose not to dig up the root system) and cause more fatal damage. I know the thought of digging up 100 Canada thistles with a spade sounds like the best way to spend a 90-degree 80% humidity Saturday, but I prefer to decrease the risk of non-target herbicide injury to surrounding native species. If you had an area of thistles right beside a pocket of well-established brambles such as blackberries or raspberries, do you really want to risk chemical drifting over and injuring or killing them?

Multiflora Rose Bush

Multiflora rose is another common invasive species that many of us learned at a young age what it was by trying to walk along that old deer trail to a stand and catching those nice thorns in the leg. It seems to be located on every farm exactly where you are wanting to go. Simple control of multiflora rose can be done by mowing the plant down to the base although this may need to be done continuously as the root system can re-sprout. Effective mowing will eventually kill it entirely as the plant will no longer be able to flower and the roots will become depleted from food reserves stored. Herbicide application can be applied through the base of the plant using chemicals such as Crossbow or Glyphosate, using water as a carrier and an adjuvant such as dawn dish soap or diesel fuel to help stick, making a cut in the base will improve herbicide movement to the root system. And once again, the best method of action is digging it up!

I know how “fun” all this sounds, but the continuous investment you put into your farm and the knowledge to be gained by learning how to identify plant species will show long term rewards to the wildlife that call your farm home. For every non-native that you remove can be naturally replaced by a native in the right setting. In areas along wooded draws I recommend planting brambles such as raspberries or blackberries which is a great forage for deer. Redosier Dogwoods is another favorite species of mine that produce a large amount of berries available for pheasants, quail and deer commonly feed on the foliage that will flourish among wood draws and near field edges.

I’ve listed just a few of the more common and easily identifiable non-natives on the landscape here in southern Iowa that most of you can get started with right away. I challenge you to take an hour or two out of your weekend on the farm and go learn about the plant species that grow on your farm. I think most of you would be surprised how many non-natives you have growing and how they could be causing harm. Below I have posted a short link of a Facebook video I did on the Cape Ivy I had growing on a farm I hunt and how it is taking over sections of the edge of the wooded draw I hunt frequently.

https://www.facebook.com/brysonwildlife/videos/297047758087201/

Thanks for reading – Ryan.