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How long to wait before it's safe to seed?

Discussion in 'Pesticide & Herbicide Application' started by AA961JESTER, Apr 18, 2003.

  1. AA961JESTER

    AA961JESTER LawnSite Member
    Messages: 48

    I want to say up front that I do not do chemical applications. I leave this up to the customer to self apply or obtain a seperate contractor. I have one customer that has a thin area in the lawn and asked If I could overseed it to thicken it up. The problem is that the customer just applied Scotts with the crabgrass control. I asked a guy and he said four weeks. Is this accurate. Do I need to do anything special because of the chem application?
  2. Runner

    Runner LawnSite Fanatic
    Messages: 13,497

    Four weeks is too short. If you work the soil up well, you shouldn't have to worry about it, otherwise, you are looking at about the end of June, early July. Right in the heat....not good.
  3. Enviro Green

    Enviro Green LawnSite Senior Member
    Messages: 324

    Yup, runner is right. Check the label on the pre-emergent, and it will tell you. You don't want to seed it and then have nothing come up, it will make you look bad.

    Check this site for labels on the chemicals:


  4. GarPA

    GarPA LawnSite Silver Member
    from PA
    Messages: 2,585

    Glad you raised this question. I have a couple of properties withe exactly the same situation. Suppose to wait 4 to six weeks after pre-em, to seed. One of the customers fert companies ( and a very good local company who is well thought of even by lco's), says its ok to seed 2 weeks after pre-em. THen I call Lesco and he says 2 weeks is ok...he says he has proof from a number of Lesco customers that 2 weeks is all you have to wait. Well thats not what all the labels tell us. I'm going to wait 4 weeks. If its too hot then to seed so be it.
  5. AA961JESTER

    AA961JESTER LawnSite Member
    Messages: 48

    Kind of puts us in a position now. I will explain the situation to the customer and if he wants seed I will not be able to give him any guarantees. To soon and I feel the preem will have an effect, too late and the heat will be an issue. Thanks guys.
  6. rkk95

    rkk95 LawnSite Member
    from west PA
    Messages: 165

    you can seed now, just work up the soil very good, it will work.
  7. cemars

    cemars LawnSite Senior Member
    Messages: 387

    As others have pointed out, the key to seeding areas that have pre emergence applied is breaking the chemical barrier. For small areas, use a hard rake or a small tiller such as a Mantis which works great. A pre emergent is just as effective at controlling crabgrass as desirable grass. So if the guy at Lesco says 2 weeks, ask him why you should expect the pre emergence to do any better?. Keep in mind that if you do disturb the crabgrass barrier in sunny areas, you will suffer the obvious consequences unless you ( or whowever is doing the fert/chem program) apply a post emerge such as Drive 75. This situation is one of several reasons that fall is a better time to seed 90% of the time. :p
  8. martytwothree

    martytwothree LawnSite Member
    Messages: 2

    How long do I have to wait to spread fertilizer/herbicide after I seed the lawn?

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