Back in July, I wrote a blog post about how we have to work every year to control the noxious weeds that are all too common in the Rocky Mountain West. In that post I mentioned we are also now dealing with another nasty invasive plant called cheatgrass, which technically isn't listed as a noxious weed -- and isn't even included in Montana's official list of noxious weeds. Nor is cheatgrass mentioned once in Montana's 2008 State Weed Plan. (You can download the 98-page document here as a PDF.) Yet in many respects cheatgrass is a worse problem than the "usual suspects" in the noxious weed universe, so the lack of official attention is very frustrating.
For one thing, cheatgrass is a grass -- it's a member of the brome family of grasses, which are widespread and provide excellent forage for livestock and wildlife. It's also called downy brome. But because of this genetic link, the only herbicides specifically designed to kill cheatgrass also suppress or kill other desirable pasture grasses, including smooth bromegrass and timothy. The other option is to use Roundup to kill live stands of cheatgrass, but of course you end up killing every plant in the immediate area.
This is why it is, in fact, much easier to control all those other noxious weeds, because they are broadleaf plants and the herbicides that kill them don't harm the grasses.
Cheatgrass is extremely aggressive, outcompeting other plants because it is often the first to come up in spring. How aggressive? Would you believe it can produce up to 10,000 plants per square yard? A single plant can generate 1,000 seeds, and these seeds have wedged awns that can puncture the skin in animals' mouths if they eat the plant. The seeds also work their way under the skin of other animals, like our dogs, and lurk for months until they rupture into an abscess.
Once cheatgrass goes to seed, the dried, dead plants form a mat that is incredibly flammable and greatly increases the fire danger. Here is what a mound of cheatgrass -- the taller, lighter plants in the middle -- looks like on our property:
Because cheatgrass looks very much like a grass, many landowners don't even realize what they've got, and thus don't do anything about it. It is possible for livestock like cattle to graze this plant very early in the spring, before it goes to seed and becomes harmful to their mouths, but it's tricky timing the grazing ... and if other grasses are available, the animals will often prefer those anyway. You can disk it up (plowing, in effect) early in the year, but you end up disking up all your other grasses, too. Hand-pulling, given the number of acres we have and human resources required, isn't really feasible.
The best control strategy is spraying in the fall, before the cheatgrass germination cycle. That's what our weed expert, Jeff Campbell of Blackfoot Weed Control, is doing in the photo at the top of this post. Jeff started spraying for cheatgrass today, and it will probably take him three days to find all the pockets of cheatgrass scattered across the ranch. (Margaret says, "This is a job for man, not goat.") He is using a one-two punch for a treatment: a mixture of Roundup for the living cheatgrass and the herbicide, Plateau, for the pre-emergent seeds. In the spring we will then disk up these areas and plant new pasture grasses.
Although we didn't even have a cheatgrass problem on the ranch until last year, you can see this stuff everywhere now in our part of Montana. It's expensive and time-consuming to control, but we're going to do all we can to get rid of it from our own 160 acres.