Cheatgrass is considered a winter annual grass, meaning this species generally germinates from seed in late summer/early fall, with some germination in the early spring. In the fall, cheatgrass will grow rapidly until colder temperatures slow above ground growth of the seedlings. However, winter frost does not kill these cheatgrass seedlings or cause them to become dormant; rather, their root systems continue to develop throughout the winter. Then, in the early spring, cheatgrass seedlings take full advantage of available water and nutrients while native perennial grasses are still dormant. These seedlings resume growth in the spring, produce many, many seeds, and die in the summer.
Hence, cheatgrass is able to “cheat” in the spring, outcompeting native perennial grasses and spreading quickly, especially in places that have recently burned or ground that is often disturbed like a roadside.
The spread of cheatgrass throughout the West is a problem for wildlife because it outcompetes native plant communities and eventually takes over, reducing wildlife’s preferred forage and habitat. However, because cheatgrass emerges in the fall, natural resource managers have a window for aerial herbicide treatment when most native plants are dormant. As such, we are able to treat large areas with very little long-term impacts to native plants in an effort to maintain our native plant communities and wildlife habitats.
Saratoga terrestrial habitat biologist