Pre-emergent for crabgrass

Discussion in 'Pesticide & Herbicide Application' started by Pistol, Aug 29, 2009.

  1. Pistol

    Pistol LawnSite Member
    Messages: 190

    Our crabgrass started coming out in mid/late July or maybe even early August. I'm skeptical that a pre-emergent put out in March has any effect on the crabgrass that comes out in July/August. Any thoughts?
  2. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,678

    The best products last longest. The more you apply--the longer it lasts. Barricade is good--so is Dimension. Either one at the maximum rate (southern rate) (or crabgrass history rate) will provide many months of control.

    A repeat application in June will also extend the period of crabgrass protection.
  3. tlg

    tlg LawnSite Senior Member
    Messages: 651

    It's been said that timing is everything. For your location March may be the ideal time. That being said there are a whole list of reasons why a pre-emergent can fail. I'll name a few. Too much rain, not enough rain, mowing too short, improper application, applied too early or too late, soil disturbed by power raking, moles, ants, etc... ( aeration studies have found that core aeration has little effect on pre-emergent control) temperature of the soil as well as air temps will also have a cause and effect on whether or not you will get decent control. In most cases a well maintained, watered and properly fertilized lawn will have few crabgrass problems. It's the poorly maintained ones that will ALWAYS get the crabgrass. 100 percent control would be ideal. In the real world this just is not possible. Late germination of crabgrass is always a possibility. This is why they make post-emergents.:):laugh:
  4. borwicks

    borwicks LawnSite Senior Member
    Messages: 615

    Every yard is different. Yard a may get watered every day. Yard B may never get watered. Figure out who has sprinklers and how often they run them. These yards may need 3 apps a year plus spraying the edges more often.

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