Good specifications must be written and all materials that a contractor uses must be thoroughly checked. Another way to prevent using weed contaminated mulch is to hire a contractor to cut and bale weed free native grass on public land. This eliminates the chance of introducing new weeds and increase the area s native grass population. When chipping brush, always do it in-house or by contractor with native plants grown on public land. Never accept free chippings from a local tree-trimmer or gardener because it may contain weed seeds.
Straw can also bring in noxious weeds if caution isn t taken.
Rice straw generally is safer than oat, barely, and wheat straw. Oat, barely, and wheat straw are prone to be contaminated with yellow star thistle. If you must buy those types of straws, buy it locally and ask the supplier if the ranch from where the straw was taken is infested with yellow star thistle or other noxious weeds. Finally, make sure to monitor sites where seed, straw, mulch, etc. has been applied for weeds. If weeds do sprout up, destroy them before they can seed.