Pre-M and overseeding?

Discussion in 'Lawn Mowing' started by gogetter, Mar 21, 2003.

  1. gogetter

    gogetter Banned
    Messages: 3,256

    My friend is going to put down Scotts with Halts crabgrass preventer on his lawn this weekend. He wanted me to aerate and overseed his lawn this spring.
    How much time between him applying pre-m and me overseeding is needed?

  2. Evan528

    Evan528 LawnSite Silver Member
    Messages: 2,144

    If im not mistaking "halts" is actually team herbicide. Look on the label to be sure but i beleave its 3 or 4 months. Much better off waiting till fall to seed. The only way around this is using tuperson Pre-emergent will will aloud grass seed to germinate...very expensive though....short residual and in my experiences with it, it dosnt work very well. This is why all my seeding is done in the fall....unless the area to be seeded is in a shady area where crabgrass will not germinate anyway.
  3. smithf36

    smithf36 LawnSite Member
    from Indiana
    Messages: 61

    Tell him not to apply any Preemergent!!! if you are going to do seeding. I have not had any luck trying to seed after someone has used a preemergent, even after waiting. Although most bags of Fert. like Scotts, will probably have a time frame to wait before doing any seeding.

    If his lawn is really in need of seed, seed it now. It is harder to get grass started, so do it now and spray for weeds/crabgrass in October or so. Late Fall is the best time to effectivey control weeds - this kills them off so they don't come back next year. Use a starter fertilizer when seeding w/o any pre or post emergents. In starter fertilizer, make sure it is high in Phosphate. Use a ratio similar to 1:2:1/2. Make sure not to use any post emergents on your new turf until you have mowed at least 2-3 times.

    Good Luck

    Joe Smith
    Earthscapes, Inc.
  4. Runner

    Runner LawnSite Fanatic
    Messages: 13,497

    Also, if you aerate, you just blew the whole purpose of the Pre-M down the drain. You will break the vapor barrier, and the preM becomes totally useless. (except to have more useless pesticide down into the ground).
  5. I believe research has provin aerification doesn.t break the barrier.
  6. Scraper

    Scraper LawnSite Bronze Member
    Messages: 1,656

    I believe I have read that as well, but I wouldn't trust it on a paying customer that I would have to rectify any problems. Not enough has been said to prove it correct in my mind.

    Jon, Tell him to postpone the pre-emergent and go with post-emergent if he really needs turf now. If not, wait til the fall to aerate and overseed. I actually skipped a couple lawns with pre-emergent today which will be getting post-emergent apps in a month as I did not want to mess up any seedlings that may have not come up from last "falls" overseeding and aerating.
  7. Gr grass n Hi tides

    Gr grass n Hi tides LawnSite Bronze Member
    Messages: 1,020

    gogetter -

    I had the same question. Most of the property I'm getting ready to treat has a nice very nice stand of fescue, but the side yard (2,200 sq. ft.) has more weeds and a couple of bald spots. My client wanted to seed this spring but is open to suggestions.

    I talked with my Lesco guy today (20+ yrs. in the business). His advice was NOT to apply pre emergent plus aerate/seed in the spring (although you could - 45 to 60 days between using the Lesco Dimension pre emergent and seeding) because there is a chance it could be counter productive & then the customer maybe has to pay to have aeration and seeding done again in the fall = an unhappy client.

    Instead, the lawn would be healthier being aerated and seeded in the fall, plus a yearly fert program would also be beneficial of course.

    My Lesco guy told me to use pre emergent on the lawn to control crabgrass/ fertilize. Then, spot spray the mature broad leaf weeds. I'm going to rake, seed and lightly compost the bald areas - of course those spots won't get any of the pre emergent.

    The plan my Lesco guy suggested sounds like the best for this particular lawn, plus I cover my bottom and cut down on the risk of an unhappy client.
  8. BB36

    BB36 LawnSite Member
    Messages: 171

    90-120 days.
  9. KirbysLawn

    KirbysLawn Millenium Member
    Messages: 3,485

    Two choices.

    1) Seed now and don't use pre-m's, spot spray weeds & crabgrass as needed.

    2) Apply pre-m and seed in the fall.

    The amount of time is not a matter really, it will be a few months after pre-m before you can seed anyway, by then you will be in summer and can't seed anyway. I would pre-m now unless grass is really **** and seed in fall.
  10. gogetter

    gogetter Banned
    Messages: 3,256

    Thanks for the input guys. He's decided to pass on the pre-m for now and have me aerate and seed instead.
    Thin grass is more of a problem for him then weeds.
    He doesn't want to wait until fall. So I will do it this week while it's still cool here.

    I'll tell him to spot treat for weeds as needed. Thanks again.

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