Slender false brome (Brachypodium sylvaticum) is an invasive grass, and one of New York’s lesser-known invasive species. In New York, slender false brome is a prohibited invasive species under regulation 6 NYCRR Part 575, which means it cannot be bought, sold, or introduced into the wild.
Slender false brome can outcompete existing vegetation including threatened and endangered species and prevent tree seedling establishment. Loss in native vegetation can harm populations of mammals, insects, lizards, snakes, and songbirds by altering food sources.
Slender false brome can tolerate a wide range of habitats especially competitive in shady or drought-stricken areas; it is self-fertilizing and can produce hundreds of seeds per plant.
Due to its similarity to other grasses, slender false brome has likely gone undetected and misidentified in Western and Central New York for years. As of December 2016, slender false brome has been located in just a few locations in New York, the Bergen Swamp in Genesee County, several areas near Ithaca in Tompkins County, a site in Onondaga County, and one site in Dutchess County near Wappingers Falls. However, it has exhibited explosive spread and aggressive population expansion in portions of New York state and poses a threat to biodiversity in botanically unique areas such as the Bergen Swamp. The grass is also found in high-use areas such as along trails in Taughannock Falls State Park, making containment difficult (1).
Slender false brome can go undetected and may be difficult to identify as there are many other types of grass that appear similar. Slender false brome can be distinguished from other grasses by its bunching, arching leaves that grow in clumps. Leaf color is bright lime-green throughout the growing season and into the late fall.
Learn how to identify this plant in an identification video, courtesy of the New York Natural Heritage Program.
Prevention is always the best option. Follow these steps to help stop the spread of slender false brome.
Small patches of slender false brome can be dug up in April and May, taking extra care to remove the whole root system. Mowing in June will prevent the plant from producing seeds.
For larger infestations, non-selective or grass-specific herbicides can be effective in some environments.
Midwest Invasive Species Information Network