Invasive Species: Grass
First of all, let me provide an update on a blog entry from a couple of weeks ago. In trying to discern whether we had an infestation of carpenter ants or field ants (both native), we now believe we misidentified them as the ground nesting field ant. One evening last week we decided to take a peek outside our door for any sign of ants, and discovered a small army of what we now believe were indeed carpenter ants progressing along our porch, up our exterior wall and into a small hole behind the trim. There went our relaxing evening on the couch. Instead we dug into our spider-infested shed for some diatomaceous earth and went hunting for ants in the attic. Diatomaceous earth (DE) desiccates the ants by breaking down the oils on their exterior, thereby infiltrating them and dehydrating them. Sure enough, the ants had been making themselves a nice little colony up in our attic, just above where they had been entering from outside. We liberally dusted diatomaceous earth (DE) everywhere there was a sign of ant, and went back to our business…which had gone from chilling on the couch to rinsing off all the insulation and DE and then going to bed. So much for relaxation.
Invasive species, which are introduced species that can harm an ecosystem, seem to be a recurring theme in my life as of late. Whether it’s documentaries, the radio, or various articles and books, they seem to be everywhere. Here at The Twenty we are not short on invasive species, mostly of the plant variety. We have Johnsongrass, musk thistle, and Eastern redcedar just to name a few. But I have a feeling that our fight with invasive species is just beginning.
From what I’ve read, Johnsongrass (Sorgum halepense) was brought into the Mississippi from the Mediterranean in the early 1800s as a forage crop. Since this time it has spread all over the southern quadrant of the United States. It is prolific. A single plant can produce 5,000 seeds in just one year, and the seeds are viable for up to 20 years. Seed dispersal is not the only method of reproduction for this already prolific plant, it also employs asexual reproduction by growing fleshy rhizomes under the ground (yes, I said fleshy rhizomes). These rhizomes are easily broken off when pulling up the plant, and any un-removed rhizomes result in an entirely new plant, or even worse, multiple plants. So, when digging up Johnson grass it is very important to get the entire root system of the plant. It is also recommended to remove the plants before they start producing seeds for the reason mentioned above: 5k seeds per plant in just one year! I am battling only two small clumps of Johnson grass on our property (we’ve found two more since posting this) and I’m having to learn quickly how to determine the difference between Johnsongrass and the numerous native grasses that live here. Alkali Sacaton, Purpletop, Sand Lovegrass and Plains Lovegrass all looks very similar to the untrained eye (i.e. me). The spikelets, or grass flowers, of Johnsongrass vary quite a bit from one plant to another—some shiny black, golden brown and others maroon—so going by the color of the flower can be quite tricky especially if you are wanting to remove the grass before it seeds. I’m finding the best indicator for identifying Johnsongrass to be the white midrib that runs down the center each blade of grass.
Eastern redcedars, Juniper virginiana, seem to have been the most prevalent invasive species on the property thus far, and over the past year or so we’ve started quite the battle. Eastern redcedars have a bit of a different story than many other invasive plants, because they were not introduced from another country, but have spread rapidly due to fire suppression. Historically, Native Americans set intentional fires as a sort of land management. Between those fires and the naturally occurring fires, the trees were confined to canyons and other places that fires could not reach. Eastern redcedars are a problem for many reasons, here are just a few issues that I take with them:
1. Eastern redcedars contain volatile oils making them incredibly flammable and the structure of cedar trees acts as ladder allowing the fire to climb into the crowns of taller trees.
2. Eastern redcedars produce a large amount of seeds and grow quickly, taking over an area which crowds out native plants and animals.
3. Eastern redcedars consume large quantities of water.
Two years ago we were lucky enough to hear about a program to help us with not only the removal of Eastern redcedars, but also to help establish a monarch butterfly habitat. The federal program entitled the “Monarch Habitat Initiative” required us to set aside a portion of our property to serve as a monarch and pollinator habitat, which as it happens was something that we were already in the process of doing. We received money for native grass and plant seeds. We also received money to help with the removal of Eastern redcedars on the east side of the property. This area by far had the most dense stands of cedars. We started by hiring a guy named Jason with a forestry mulcher. A forestry mulcher is essentially a bobcat with a giant shredding implement on it that quickly chips away anything in it’s path. They are pretty incredible machines. We had him clear the perimeter and create pathways for another guy, also named Jason, who we allowed to come onto the property and harvest the cedar for lumber. A bonus was that we were able to pay him labor to mill some of the cedar that we then used and will continue to use on projects around the house.
I thought I was going to end this blog by talking about the Eastern redcedar trees except during my writing I came across my most rivaled enemy: Bermudagrass! This is the ultimate invasive species in my opinion. Bermudagrass (Cynodon dactylon) has tricked many people into carefully feeding, watering, and manicuring it for the purpose of a lawn which requires an incredible input of fertilizers, water and fossil fuel to maintain. This grass, as well as many other non-native grasses, have been introduced for the purpose of turf. Turf grasses are unfit for many species of native plants and animals including my beloved Texas horned lizard. If you’ve spent any time digging Bermudagrass out of veggie gardens or flower beds you know the removal of this grass is more taxing than most any other. The intricate web that the grass creates from sending off runners paired with the fleshy viable rhizomes earns it the top place on my least favorites list. It has also been used quite successfully by farmers for grazing cattle.
As quoted in “Field Guide to Oklahoma Plants: Commonly Encountered Prairie, Shrubland and Forest Species:”
“Monotypic stands, such as introduced pastures, are detrimental to wildlife and may effectively eliminate an area as suitable habitat for many species.”
In other words—wasteland for most native wildlife.
So, needless to say I have spent many hours defending the honor of our property from this noxious beast. It is no easy task, but ultimately worth it in the long run if we’re to have any hopes of establishing any other native grasses on the premises. Bermudagrass looks very similar to a few other native grasses on our property, Buffalograss and Windmill grass for example. This is posing yet another issue for this amateur. How do I tell the difference between these grasses? Luckily the grass spikelets vary greatly, so with the use of the field guide mentioned above I can tell the differences between the grasses.
There has definitely been a learning curve to most any project these “city folks” have been tackling out here at The Twenty. Sometimes we learn things the hard way, but all in all things are going pretty good at the moment.