Rough bluegrass (Poa trivialis) is sometimes used as a turfgrass, most often on a golf green in winter. It’s not purposely planted but is already there and can be groomed to accommodate the golfers. This is about the only instance when it is used successfully, or intentionally, other than an ornamental meadow grass. Most other times it is a weed, an unwanted grass in the lawn that we want gone.
What is Rough Bluegrass?
Rough bluegrass is a spreading, aggressive, grass-like weed. It begins to grow and spread in autumn. Once it gets into your lawn, it takes over the grass already there, then dies back in summer heat, leaving bare spots where your grass once grew.
Don’t confuse it with Kentucky bluegrass, although it is in the same family. Invasive rough bluegrass looks like bentgrass and is related to annual bluegrass, which can also be troublesome. Leaf blades are lighter in color, a light-yellow green with a reddish hue when dry conditions persist. It blooms in June, producing seeds that further its spread.
When conditions are favorable, this grass creeps by shallow stolons (runners) and quickly fills an area whether grass is planted there or not. Cool temps and moist soil encourage its growth. It has shiny, fine blades and is easy to distinguish from the turf you want growing in your yard.
How to Kill Rough Bluegrass
To get rid of this grass in your lawn, improve drainage and cut back on watering. Hand pulling is not effective for large areas.
Rough bluegrass info says keeping a dry lawn is one of the best ways to prevent its invasion. It does not tolerate drought. The best defense is keeping your lawn healthy so there will be less chance that rough bluegrass in your lawn can survive. You can also combat it by:
- Water the lawn infrequently and deeply. Deep watering goes down further than the short root system of the weed.
- Cut the grass no shorter than 3 to 4 inches (8-10 cm.). Lawns with lush, healthy turf are harder for the weed to invade.
- Fertilize the lawn regularly. Most lawn care professionals recommend four feedings per year.
- Apply a pre-emergent weed control product in late summer.
If you were wondering is rough bluegrass a weed, hopefully your question was answered. Practice these methods to keep the weed under control. If it’s already caused massive grass dieback in your lawn, check into reseeding those areas. When reseeding the lawn, remember to let the early morning dew do its job before you begin watering for the day.