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Discussion in 'Pesticide & Herbicide Application' started by quidproquo, Dec 11, 2005.

  1. quidproquo

    quidproquo LawnSite Member
    Messages: 5

    :angry: I just went out to dig out my septic tank cover-it's about 12" down-and what did I find? Grubs!!! Under the 13" of snow we got on Friday they were snug as a bug under my lawn. My question is this-I use Scott's GrubEx every spring year but still the little buggers survive. Should I apppy it 2x a year or more? Is there a better product? I've seen ads for some tiny nematodes- has anybody ever used them? I'm in northern CT, and only have about 3 1/2 acres of lawn to cover....Thanks guys
  2. NattyLawn

    NattyLawn LawnSite Bronze Member
    Messages: 1,643

    When did you apply the Grub-Ex? According to the Scotts website, it's best applied in June and July. In my area, Merit was applied after July 4th when the Jap Beetles were active. This season was out of whack with the drought conditions, and even with Merit apps, a few customers still had grubs. It all goes back to watering the product in effectively.
    Also, there was some info out of Boston College that stated that some grub species were surviving the floods in the Northeast, and there were in fact two waves this fall.
    Do a search for Nematodes or look in the organic forum. I haven't used them personally, but plan to next season. From what I have read, the conditions have to be perfect for them to work well, and the cost might be pretty high for 3.5 acres. Also, you can check out http://www.thegreenguardian.com/ and take a look at Blistering Defense...Good luck...
  3. teeca

    teeca LawnSite Bronze Member
    Messages: 1,202

    it's very normal to have grubs, even though your treating them yearly. it's about control, not elimination. your alowed somewhere around 6-12 grubs (PLEASE DON'T QUOTE ME ON THIS, but it's close) per 1 sq ft before any noticable turf damage will occure (on an average lawn).
  4. NattyLawn

    NattyLawn LawnSite Bronze Member
    Messages: 1,643

    Took this from Ohio State website:
    Populations of annual grub species that are less than six grubs per square foot can usually be masked by water and fertilizers. Populations between 10 and 15 per square foot can cause significant turf damage in September and October. Of course, populations occasionally reach 40 to 60 grubs per square foot and these levels can cause damage by late-August.
  5. teeca

    teeca LawnSite Bronze Member
    Messages: 1,202

    ya, what he said

    anyway, now is not the time to put anything down to kill them. in the spring around april/may they will venture back to the rootzone of the grass and start feeding again, this will be the time to put down DYLOX 6.2 to kill them off.
  6. DiscoveryLawn

    DiscoveryLawn LawnSite Senior Member
    Messages: 408

    Don't even bother trying to kill them in april/may. They are not going to eat enough to cause any damage in the spring. By June they will have become beetles and flown off anyway. I challenge any person on here to find grub damage on cool season turf in the spring. If Ohio State University has never documented spring grub damage, I doubt anyone else can find it either (if so, will likely be a miss-diagnosis).

    Nattylawn is exactly right. The population level will have to be above 6 (usually more than 12) per sq. foot in order to warrant cuarative control. Late summer/early fall is the only time grubs are going to eat enough to cause damage. Spring curative apps are a waste and irresponsible. When applying merit (in june/july) be sure to water it in within 48 hours to ensure product does not start to break down before it makes it to the root zone. Also, make sure your application rate is accurate. Another thing, Merit gets tied up in excessive thatch. Make sure thatch layer is not thicker than 1/2 to 3/4 an inch when applying.
  7. lawnservice

    lawnservice LawnSite Senior Member
    Messages: 589

    excuse my ignorance, we dont use scott's brand grubX, but isnt the active ingredient in grubx Mach2?
  8. DiscoveryLawn

    DiscoveryLawn LawnSite Senior Member
    Messages: 408

    Actually, you are right! GrubX is halofenozide (Mach 2). Mach 2 does not have to be watered in for 10 days. Also, Mach 2 can be used as a limited curative. Excuse MY ingnorance. I don't know what I was thinking. I do not use "GrubX" either, but I do use Mach 2 as well as Merit.
  9. marko

    marko LawnSite Senior Member
    Messages: 963

    I agree. Grubs are ok to have, you just want to limit the number to the threshold where the damage is not obvious, or the cost to repair damage outweighs treatment. If your under 10 -12/sq ft and have thick growth, I would not worry about it. They will not eat much again till emergence time. Its their babies you'll have to worry about.
  10. New Green

    New Green LawnSite Member
    Messages: 57

    It may not be the grubs feeding in the spring causing damage, it seems to be the skunks.:realmad:

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