False-brome is known to form dense patches in disturbed areas (roads, streams). Seed is then carried into undisturbed forest, woodland and grasslands.

Despite being a bunch grass, false-brome has a large numer of seeds that allow it to cover and dominate both forest floor - tolerating up to 80% shade - and bright, open spaces like meadows or oak savannahs. Like many species, the arrival of false-brome often reduces plant and animal diversity because it displaces natives. It also reduces tree seedlings that replace old, fallen trees.