Poa Annua (Annual bluegrass)
Learn how to kill this grassy weed and prevent it from leaving bare spots in your lawn.
What Is Poa Annua?
Poa annua, or annual bluegrass, is one of the most common and widely distributed grassy weeds in the U.S. It is widely adapted to different site conditions and cultural practices.
Poa annua is light green in color with coarse-textured leaves and produces unsightly seed heads in spring. Both annual and perennial types exist. Perennial types are more common in areas that are watered frequently, and fed lots of nitrogen. It is also common in areas with lots of shade or that are compacted.
Seed germinates in late summer or early fall. The seedlings grow in the fall and flower in spring. An individual plant can produce hundreds of seeds that can remain dormant in the soil for years. Annual bluegrass usually dies off in summer but can survive if the landscape is regularly watered.
How to Kill and Prevent Poa Annua
Poa annua should be removed before it flowers and produces seed. Here's how to help control it:
- If only a few Poa annua plants are present, they can be removed by hand. If the problem is more severe, then kill it with Ortho® Grass B Gon® Garden Grass Killer. The ready-to-use formula can be used on landscapes, hardscapes, and groundcovers to kill existing grasses without harming listed landscape plants (when used as directed). Please note this product should not be used on lawns.
- Mulching can be an effective control against Poa annua because it helps prevent seed germination by blocking sunlight from the soil.
- Properly spaced plants that are watered deeply but infrequently and fed properly are better able to outcompete Poa annua in garden beds.