 |
| Affected Area |
Keys to Identification
- Annual bluegrass grows 2 to 8 inches tall when unmowed.
- It is tolerant of mowing heights typical for home lawns.
- The grass has a lighter green color (sometimes described as “apple green”) than other cool-season turfgrasses.
- Annual bluegrass has flattened sheaths that are bent at the base and often rooted at the lower sheath joint.
- Mature leaf blades are often rippled part way down and vary from 1 to 3 inches in length.
- Leaf blades end with boat-shaped leaf tips.
- The inflorescence (flowering structure) is a terminal panicle that varies from 1⁄2 to 4 inches in length.
- The majority of annual bluegrass seedheads are formed in spring (April to June).
 |
| Annual bluegrass seed heads. Millie Davenport, © 2010, HGIC, Clemson Extension |
 |
| Ripples on leaf. UMassAmhurst Extension Program |
Control
In small landscape beds, annual bluegrass can be hand dug or controlled with an herbicide. It is best to prevent the spread of annual bluegrass by maintaining optimum cultural conditions and using a 3-inch mulch layer to block weed development. Once annual bluegrass has made its way into a landscape bed, an herbicide may be necessary if hand pulling or hoeing is not practical.
Whenever using pesticides, always read and follow labeled directions or have pesticides professionally applied by a licensed pesticide applicator.
Additional Information
Annual Bluegrass - University of California - IPM
Annual and Roughstalk Bluegrass Management for New Jersey Home Lawns - Rutgers University
Which is it, Annual Bluegrass or Kentucky Bluegrass? - Purdue University
Poa L. - USDA Information
Turfgrass Morphology - University of Illinois at Urbana-Champaign
