Medusahead grass is an “Ecosystem Transformer” species. Not only does it compete for resources with other plants, but it can change ecosystem function to favor its own survival at the expense of an entire ecosystem. It thrives in areas with hot dry summers and cool wet falls and springs. Its seeds travel well on animal hides, clothing and tires. It promotes fire as just another way to expand its territory, burning hot and fast, and then rebounding more quickly than the native vegetation. It isn’t toxic, but it isn’t very edible either. Though it’s similar to other forages in protein, fat, fiber and lignin, it is also high in silica (think “sand”) that slows passage through the rumen. That means that animals tend to avoid it. Uneaten stems create a thatch that suppresses other plants, until Medusahead is the primary plant. This can reduce grazing capacity on rangelands by 75 to 80%. It’s a scary invasive, and that’s why lots of researchers, ranchers and land managers are working together to find a way to slow its spread and beat it back if possible.
If you’re worried about Medusahead, (and if you’re in the areas shown in the map, you should be), you need this Medusahead Management Guide. It was published in 2014 and has a wealth of information on how the plant grows (so we know what it’s weaknesses are) and how to fight it. The emphasis is on getting to the plant before it flowers in the spring so that it can’t set seed, and if you’re in an area where it has already developed a heavy thatch, to break it up so that other plants have a chance to grow and thrive. The Guide describes how and when to use fire, mowing, tilling, grazing, chemicals and revegetation to slow Medusahead and give other plants a chance to compete against it.
If you’re in Medusahead’s path you can start fighting it now by focusing on prevention. Don’t transport animals directly from an infested area to clean range during the summer. Hold them between sites for a few days to give them a chance to shed attached seeds. If you’re near an infestation, keep the vegetation healthy in your pastures. Overgrazing, especially in the spring, gives Medusahead just the opening it needs to head over to your place. You might even consider planting “fences” of vegetation to contain infestations. Researches found that these buffers (like the one they planted of perennial desert wheatgrass) prevented about 98% of Medusahead seed spread.
If Medusahead has already arrived at your place, don’t give up. Work with your neighbors and other land managers to develop a long-term, integrated approach to managing this invader. You’re going to have to start early and stay late, and maybe work with folks you never thought you’d work with, but it will be worth it in the long run.