Simazine timing

Discussion in 'Pesticide & Herbicide Application' started by B-Easy, Oct 14, 2009.

  1. B-Easy

    B-Easy LawnSite Member
    Messages: 85

    New to using this product. I was told to wait approx. 2 weeks after the first frost before using this product to ensure I do not hurt the desirable turf grasses. It does not say anything about waiting for dormancy on the label (Princep). Bermuda and Buffalo wuold be treated in this case and we are in the transition zone. My question is, if the warm season grasses have gone dormant won't the majority of the grassy weeds we are attempting to eliminate also be dormant?

    VARMIT COMMISSION LawnSite Senior Member
    Messages: 547

    Your targeting winter weeds not summer weeds. Its a fall (short lived very friendly to bermuda) preemergent and has lots of post activity. LCO's around here have been spraying it for several weeks now. If your wait for the first frost then two weeks to apply your henbit which it will control will be everywhere. I saw some henbit yesterday. Your north of me so your already got it if you look hard enough. Worry about control on summer grassy weeds in the spring. Target winter weeds now.
  3. Volman

    Volman LawnSite Member
    from West Tn
    Messages: 106

    Varmits right. We've been spray princep for almost 3 weeks. (Rains every other day)It wont hurt your bemuda. Don't know anything bout Bufflo.
  4. ted putnam

    ted putnam LawnSite Platinum Member
    Messages: 4,669

    I use Sim-Trol 4L. Simazine. The label reads not to apply until after Sept 1 for winter annuals except where Annual Bluegrass is your target. For that after Oct 1. I started spraying it at about that time(2 weeks ago). I spray it as soon as I can in the Fall when using it for it's Pre- emergent qualities because(and it's just common sense) you have to apply it before the weed emerges or it's not a "Pre" anymore. At that point it will only be effective as a "Post" and that may be limited by environmental factors in the Fall. I guess what I'm saying is you need to spray it now if you want it to work as a pre-emergent and you are safe to do so...
  5. B-Easy

    B-Easy LawnSite Member
    Messages: 85

    How is it as a post emergent herbicide? Can it be used as a stand alone product in the fall on the warm season grasses or should it be mixed with a 3 way herbicide? My main concern and reason for using this product are the winter annuals. However, I do still have broadleaf weeds (already growing) to consider and I'm worried I could be missing these.

    VARMIT COMMISSION LawnSite Senior Member
    Messages: 547

    Tiny henbit, yes it will control. Dandylions, no way. Use your 3-way also and pickup any broadleafs present. The list of post properties are too limited not to use fall as your second 3-way post app.

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