Forest and Kim Starr, Starr Environmental, Bugwood.org
Orchardgrass is a perennial weed that grows best in cooler weather, such as in spring and fall. When it emerges, it grows very quickly and reaches heights up to 10 feet. It's a light-green weed, very grassy and forms as a tuft of leaves that grow from shoots and culms; these culms appear strawlike as they mature, seen in the picture above.
This weed resists frequent mowing and can thrive in shady areas. If there are few weed patches, they can be removed with a shovel. However, go down at least 4 or 5 inches below the soil to remove all the stems. Pre-emergent and postemergent herbicides containing pronamide can help to kill and control this weed depending on the season.