Who's Got Crab Grass Where There Was Grass

Discussion in 'Pesticide & Herbicide Application' started by CLARKE, Aug 13, 2001.

  1. morturf

    morturf LawnSite Senior Member
    from midwest
    Posts: 475

    oh boy.....you guys are really going now.....i have to go with ray on this one........i have seen enough poa annua and enough crabgrass, that post is crabgrass. The leaves are way too big for poa anything.......lol. If you look real close, you can see the hair on the leaves that would make the link Larry posted of the black and white drawings show that it is crabgrass......maybe we all need to call Chemlawn for a lawn analysis!!!!!!!!!......We all know what pros they are a growing crabgrass......

    one more thing........Take all of this with a grain of salt......lol
  2. powerreel

    powerreel Banned
    Posts: 481

    Does anyone have a photo of goosegrass or barnyardgrass, maybe it is one of those? Our "weed" grasses start in the fall with too high N, or too early fert ap in spring. I scalp reel super low the week after a spring fert ap. then raise it a tad. It can make a lawn look like it has zits in the winter. Richard Martin said it right about seed travel, in the fall I bleach mowers and pruners between houses- fungi travel this way also. Is it really worth it to treat and apply all that stuff?
  3. http://www.agronomy.psu.edu/Extension/Turf/WeedMgmtb.html#AnnualBluegrass

    If the lawn is mowed 7-10 days you will be hard pressed to find a seed head.

    If you don't have a seed head it is hard to determine the type of grass and threfore the control (if any) of that grass.
  4. morturf

    morturf LawnSite Senior Member
    from midwest
    Posts: 475

    ok....now here is the skinny. Read'em and weep. These are the best pictures i could come up with on short notice. Hope it helps.

    poa annua- usually a very fine leaf and a small plant that if dense enough it will be confused for regular bluegrass

    goosegrass - very compact growth habit...looks like crabgrass but much more dense of a plant.

    crabgrass - grows upright until about the 3 tiller stage, then spreads out,can get anywhere up to 4 ft(yes feet) in diameter, when it matures the longer leaves will root down. at this point, if it is in your yard....you have a problem.

    barnyard grass - has an upright growth habit when young, once it gets past the 4 leaf stage it hardens and begins to lie down.

    I still say that the picture is crabgrass!!!!
  5. George777

    George777 LawnSite Senior Member
    from Alabama
    Posts: 305

    this question is for ya PRo's. At what Developmental stage is it best to control crabgrass? if the weed is in the Reproductive stage do you spot treat it When daily temps are in the mid 90's. or do you just wait until you apply your Pre-M?

    I don't have my applicators lisence but I'm in the process. I think the first frost would kill the present crabgrass and it is the seeds I would imagine I would want to stop from germinating.

    i understand that following the herbicide label is key, but if Temps stay above 90 wont the tuf turn yellow and look terrible?

    I have learned enough to know you do not treat anything unless you have the weed identified.

    I think for anyone to bow your chest and make a comment about not being a pro is uncalled for. I guess you just know everything about pest control?? Remember where you started and think of others who are starting out. I doubt if anyone started out being a so called PRO. If I should get to the point when I think I know all thier is to know then I better find another field, because in my life time I know I can't possibly master it all.

    CLARKE LawnSite Member
    Posts: 145

  7. Mscotrid

    Mscotrid LawnSite Bronze Member
    from USA
    Posts: 1,456

    If you need a seed head to tell the difference between Poa annua and Crabgrass maybe one should consider a liitle refresher course in plant identification.

    lets get another thing correct. Crabgrass is not a weed, it is a warm season annual "grass". Though many books describe a weed as "Any undesirable growth within a given area".

    As a turf professional I feel this forum should be used to help and educate those who come here for advice. This site was not intended to make one feel like a idiot, whether posting or responding to a post. Either way a responding post should realize we all live in different parts of the country, and what might seem rediculous in your area might be a normal practice in another.

    CLARKE LawnSite Member
    Posts: 145

    Thanks to every one who responded, this has been very
    HELPFUL AND INFORMATIVE TO ME, THANKS AGAIN CLARKE...:blob1: :blob3: :blob4: :blob2:
  9. osc

    osc LawnSite Senior Member
    Posts: 502

    This thread is a joke right?
  10. Cleve

    Cleve LawnSite Senior Member
    Male, from Rockmart, GA
    Posts: 398

    Thank you moturf (I think I spelled that right). For the photos of "smooth crabgrass". Looks like what I'm working with at one of my customers.
    (above added after the post below):
    I have a question regards another possible way of controlling these weeds this late in the season.
    Last year one of my customers had a really bad problem late in the season with what I believe was crabgrass(maybe not). Only reason I don't think it was crabgrass is that it was really dense and low growing. I tried spot spraying the weeds with Roundup a few weeks before aerating and overseeding with fescue. Worked fairly well even though the lawn looked so bad that his neighbors started asking questions before the new seeds came up. Thankfully the new lawn looked great by the end of the year.
    This stuff has raised it's ugly head again but in a smaller quantity. I'm just not going to go the roundup route again. Too much worry and labor on the dead areas.
    Since these weeds should die down in the winter I would like to just aerate or power rake and overseed and just try to control them in the spring. Problem is, the weed leaves are so thick that the new fescue seed won't be able to properly germinate.
    I have a Jocobsen power rake (dethatcher). I did a test on a small area of weeds this week by running the power rake over them. Did great job of literally ripping the weeds away and scratching the soil surface. This machine even leaves most of the healthy fescue in and around the weed spot. Great preparation for overseeding. Thought is that the weed will die anyway this winter but leave the root system to germinate in the spring. If I can get new grass growing there this fall and get the PreM down early enough the weeds might not survive.
    Does this sound like possible idea?
    Thanks, Cleve.

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