Mowing, Mulching and Seeding to Control False-brome on the Eugene District, BLM, Oregon: December 2008 Status Report

New populations of false-brome are being reported across western Oregon at a rapid rate. This species establishes in disturbed habitats as vehicles and equipment spread the seed to new areas. Since road systems are frequently disturbed, they serve both as a source of seed dispersal as well as likely locations for the establishment of new populations. We expect that false-brome expansion can be slowed by mowing the grass before it sets seed, covering the occupied sites with mulch, and establishing competitive native vegetation.

Past experiments have shown that mowing can halt seed production for one year, while mulching in combination with mowing may reduce false-brome abundance and seed production for periods of up to two years (Blakeley-Smith and Kaye, 2006). Although blue wildrye straw is an effective mulch that is available commercially, it is expensive. BLM has a large source of both cottonwood and Douglas-fir mulch that they wish to test as a roadside mulch to suppress weeds. It is unknown how effective these other sources of mulches are at preventing re-growth of false-brome. Additionally, establishing native vegetation on roadsides has been a difficult task due to compacted soil, availability of native seed, and the presence of aggressive introduced species. This project aims to develop effective control methods for false-brome with an emphasis on reducing spread of the species along roadways.