Identify this weedy grass...

Discussion in 'Lawn Mowing' started by Westbrooklawn, Apr 2, 2005.

  1. Westbrooklawn

    Westbrooklawn LawnSite Senior Member
    Messages: 427

    I am seeing a lot of this weedy grass popping up in my fescue lawns this spring. It is light green in color and grows in patches from plate size up to about 9 sq. ft. It is fine leaved and grows faster than the fescue.

    What is it, and how can I control it? I am afraid it is some kind of annual blue grass (although lighter and more patchy than what I usually see), and when it dies with warmer weather it will leave large bare spots?

    Any help would be appreciated.

    weedy grass 1.jpg

    weedy grass 2.jpg
  2. pcguy

    pcguy LawnSite Member
    Messages: 51

    Have any of these people done seeding themselves? It looks like the stuff you get with K-Mart Quick Lawn grass seed. If so, 60% or so will die out and the rest will blend in.
  3. Westbrooklawn

    Westbrooklawn LawnSite Senior Member
    Messages: 427

    No, the lawn pictured was overseeded by me last fall, and I used Lesco Transisiton Blend which does quite well in this area. Some of the lawns I seeded have the weed pictured, others do not, and I used the same seed for overseeding all.

    I few folks on another site have identified this as Poa Annua or winter bluegrass, but I don't believe it is. The color is way too light, and it doesn't form seed heads the way winter bluegrass does. It is very thin bladed and forms in large patches.

    Any other ideas??
  4. GroundKprs

    GroundKprs LawnSite Bronze Member
    Messages: 1,969

    First look suggests Poa trivialis. Small possibility of annual blue or bentgrass, but that light green color is typical of Poa triv (AKA rough bluegrass, roughstalk bluegrass) in early spring. Color will match up later in year. But it will spread and overtake the whole lawn eventually.

    It has been determined that Poa triv is generally introduced in the seeding process. It comes from inadvertent contamination in seed production facilities. Poa triv is a marketed seed, usually used in overseeding southern golf courses for winter. It dies out as soon as it warms up and regular golf turf takes over. But in C3 areas, especially in environments conducive to its survival (wet, compacted sites), Poa triv will behave as a perennial.

    The turfseed industry in now moving to quarantine Poa triv production facilities, so no other seed is processed in Poa triv facilities. But it may be years before this is completely effected.

    No selective control at present.

    This will help you ID your weed: AY-11W

    And here is a good discussion of Poa triv (& annual blue): AY-41W
  5. dkeisala

    dkeisala LawnSite Senior Member
    Messages: 911

    It's poa annua or annual bluegrass. It's unsightly but that's about it. Being soft textured, it doesn't mow well, leaving behind tufts of unmowed grass. It won't leave bare spots when it dies out as the weather warms. Poa seed heads are short so you don't get much of it when you mow and the seed is viable within days of germination. Pre-emergents, such as Dimension, Pendulum AquaCap and others, applied twice per year are great at diminishing the problem over time.
  6. Westbrooklawn

    Westbrooklawn LawnSite Senior Member
    Messages: 427

  7. Harry0

    Harry0 LawnSite Member
    from NJ
    Messages: 220

    My first thought was nutsedge-but poa annua is a good guess -both are a pain in the butt to control.
  8. Planet Landscaping

    Planet Landscaping LawnSite Senior Member
    Messages: 607

    Poa annua is my guess :confused:
  9. ProLawns

    ProLawns LawnSite Senior Member
    Messages: 476

    It's definitely not poa annua. When poa annua is that healthy it's full of seeds especially this time of year and I don't see any seed heads. It resembles nutsedge but it's to early. It's poa trivialis which is a perennial. It's hard to get rid of. You have to use roundup and than over seed or sod.
  10. Littleriver1

    Littleriver1 LawnSite Senior Member
    Messages: 811

    Looks to me like some one had a bird feeder hanging there all winter.

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