Orchardgrass is very competitive in other grasses. Orchardgrass tolerates full sun to partial shade. Orchardgrass does not form large patches, as it does not spread by either rhizomes or stolons. The best way to prevent the introduction of orchardgrass is to use clean seed. Make your postemergent herbicide application to orchardgrass that is actively growing and in the 2 leaf to flower stage of growth.
Control is only available with a non-selective control product.