Andropogon virginicus, also known as Broomsedge Bluestem (or just Broom Sedge), Yellowsedge Bluestem, and Whiskey Grass is a clumping grass that is native to the southeastern United States, and this includes where our farm is located in East Tennessee.
In the photo above, you can see how thick it has grown in the pastures on our farm.
When we first moved to our farm almost 2 years ago, I knew this plant was going to be a great indicator species for me to monitor the health and regeneration of our pastures.
Broomsedge in a pasture tells me that the pastures have been overgrazed or neglected or both. While grazing animals will eat it in Spring and early Summer, it is not preferred. It has less nutrition than other pasture plants, and once it dries out in late Summer and early Autumn, grazing animals will mostly ignore it.
A fun photo of our kids right after we bought the farm… but look at all that broom sedge and red cedar taking over the pastures!
Why is it an indicator of overgrazing?
Well, as many graziers like to say, “herbivores eat dessert first”. They will choose the pasture grasses and plants that have high levels of sugar and/or protein and/or mineral content first. Examples of these plants include clovers, bluegrass, rye, timothy, etc. Ideally, our pastures will have high proportions of these plants.
Herbivores will eat their favorite “dessert” plant first, then wander over and eat another “dessert” plant, and then wander some more and eat yet another “dessert” plant. All the while, they are ignoring the less desirable species of grass or pasture plant.
When the animal eats the leaves of one of these plants, the photosynthetic ability of that plant is suddenly and significantly reduced. The plant now has to rely on the energy reserves in its roots to stay alive. It will use these energy reserves to grow new leaves, or as I like to say, new photosynthetic energy generators. Depending on the season and plant species, this new growth (regrowth) will start in 4-10 days.
If the pasture is small or there is a high stocking density (i.e. a high number of animals per given area of land), the animals may east the less desired plants only after they have eaten all the highly desired “dessert” plants first.
If we leave the animals on the pasture too long during the active growing season then, by the time the animals make their way around the pasture, there has been sufficient time for the “dessert” plants to start to put on new growth.
Now, the only plant an herbivore likes more than a “dessert” plant is a “dessert” plant with tender regrowth!
So the “dessert” plants will be eaten again, just as they are trying to regrow. They have used up a significant amount of their energy reserve in their roots to put out new leaves, and these leaves are now gone again. So the plant has to pull even more stored energy from the roots to try and regrow even more leaves. A plant can only do this so many times before it has no energy reserve left, and then the plant will die.
All the while, the less desirable plant continues to grow. It matures. It develops and drops its seed right next to the “dessert” plant that has been grazed, literally, to death. Now that less desirable plant can move in to the space previously occupied by the “dessert” plant.
This is how, over time, a pasture can become full of less desirable species of grasses and plants.
This is exactly what has happened on my farm. The previous owner let a neighbor open graze his cattle (that means let the cattle have free access to all pastures) for well over 10 years, maybe more.
Fortunately, not all “dessert” species were lost. But the less desirable species, especially the Broomsedge Bluestem, were given an unfair advantage for a long time. Now my pastures are covered with it.
We are rotationally grazing our sheep as one method to improve our pastures.
So what am I going to do about it?
First, we are going to manage our pastures with intensive rotational grazing techniques. This is going to make the biggest long-term impact on the health and improvement of our pastures. I have written about it multiple times in the past on my site:
- Sheep paddock rotational grazing
- Mob grazing with sheep
- More evidence of our farm’s regeneration
- Rotational grazing Azores style
Second, since this plant is a native to my area, I am not overly worried about it. But it is not an ideal plant. I would rather have more of the “dessert” species in my pastures. The rotational grazing methods we are using will work to regenerate our pastures. But I think we can speed the regenerative process up a bit.
Third, we will speed the regenerative process up by thinking a bit about how the less desirable species grows (in this case it is Broomsedge Bluestem). It is a clumping grass. It is eaten by our sheep in the Spring and early Summer. By late Summer and early Autumn, it will dry out and form fairly thick standing clumps. These clumps will stay standing all Winter long and well into the next year. By staying standing, it will shade out the growth of other pasture species, thereby maintaining its position in the pasture.
On the left of this photo is the field I am actively mowing… cutting the Broomsedge. A swale is holding water almost a week after the last rain. This moisture has helped “green up” the landscape downhill, but that area was also mowed a few months earlier, and so that pasture was not shaded out by the tall, dense Broomsedge clumps.
Forth, I use this information to develop management plans to encourage other plants’ growth. Specifically, I let the animals eat the Broomsedge in the Spring and early Summer. Then, especially in Winter when we will not interfere with the active growth of other plants, I knock down the dried standing clumps of Broomsedge. I do this by cutting it with my riding mower. Yes, I am sure I get some strange looks by my neighbors when I am riding my small mower in the middle of our pastures. But there is a method to my madness. By cutting those standing clumps in Winter, I am preventing the Broomsedge Bluestem from shading out the other plants come Spring. I am trying to give the unfair advantage back to the desired species.
About a week after mowing the area uphill of the swale, there is already new green growth. This is mostly fescue, a cool-season grass that is getting a jump start due to the recent warmer weather AND my letting in more sunlight by cutting the Broomsedge.
There are a number of other techniques that could be used. We could add seed of desirable plants. We do this a bit right now. I broadcast clover seed in Winter (this is known as frost seeding). Other people my use a tractor and seeder to drill (i.e. plant) seed in the pastures. Some people may plow up a field and reseed, and other people may use chemicals to kill all the grass in a pasture and then reseed with the plants they desire. We do not have a tractor, and I am pretty adamant about avoiding all synthetic chemicals on our property. This is how we came up with the methods we are now using.
All photos in this article are mine. Please ask if you would like to use them.
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