Smooth Brome


Scientific Name: Bromis inermis

Description. Smooth Brome is a perennial grass native to Europe that was introduced to the United States in the late 1800’s. It is 1-3 feet tall and produces large seeds, 1/4″ long. Smooth brome looks very similar to a native brome. However, the native brome grows in small bunches, whereas smooth brome grows in large homogenous monocultures. Smooth brome is a deeply rooted grass that prefers sunny open areas. Smooth Brome grows well in cold climates and is fairly drought resistant. Smooth brome establishes in disturbed areas, especially roadsides. Once it has a foothold, it will spread into native plant communities and form very large monocultures. It outcompetes native wildflowers over time. While few land managers attempt to control this grass, it is a problem in native wildflower meadows. We encourage the public to keep an eye out for this plant in grass seed mixes and preferentially purchase mixes that do NOT include smooth brome.

Methods that work.
1. Black Plastic. At RMBL, we cover smooth brome patches with plastic for two growing seasons, remove the plastic and reseed with native seeds. The area returns to native vegetation the following summer. The plastic can be unsightly, but mulch or wood shavings could be put on top of the plastic to hide it.
2. Mowing. If this grass is growing in a lawn that gets mowed, it isn’t going to produce seeds and spread. It’s harmless in a lawn.

Methods that might work.
1. Grazing. Cattle like to eat all sorts of grasses, including smooth brome. Anecdotal observations suggest that cattle grazing might control the grass, allowing native wildflowers to persist.