Snapshot over or under mulch?

Discussion in 'Landscape Architecture and Design' started by UrbanSanctuaries, Jun 13, 2013.

  1. UrbanSanctuaries

    UrbanSanctuaries LawnSite Member
    Messages: 2

    Ok---got into a discussion with a client today--(I am a Landscape Designer/ Horticulturist)---She asked why the pre-emergent (Snapshot) was being put down over the mulch (it looks like cornmeal mulch)--I have always put treflan down on top of mulch for the airborne weed seed--Is this the proper application?
  2. ztuttle7

    ztuttle7 LawnSite Member
    Messages: 17

    We provide two applications. One prior to mulching and one in the summer on top of the mulch. Depending on the contract.
  3. UrbanSanctuaries

    UrbanSanctuaries LawnSite Member
    Messages: 2

    It seems like if disturbed soil with inherent weed seed , and dandylion / thistle in the air--an over the top application is good--the client is justconcerned about the look of the yellow stuff on top of the dyed brown mulch ( by the way--an hour later the dye from the mulch had colored the Snapshot). Is it just the aesthetics, or is the topping the way to go?
  4. Toro 455

    Toro 455 LawnSite Member
    Messages: 238

    The ideal application is under the mulch. It gets the herbicide right on the soil where it's needed. If you topdress it over the mulch you have to wait of rain to wash it down to the soil. Then the mulch can absorb some of it or keep it off of the soil all together.

    If you have to topdress like over existing mulch you should make sure the mulch is broken up and then maybe rake it in a little to help settle it down to the soil. If it doesn't reach the soil it might as well be in the bag.
  5. andersman02

    andersman02 LawnSite Senior Member
    Messages: 579

    Hello fellow designs/horticulturist :waving:

    This is actually something one of my clients asked me a week ago prior to a mulch job. I told them in a perfect world, I would use preen or Pre-Em, Snap shot w/e you use, prior to mulching, water it in, then mulch and lay down another application. Couple problems with this is we usually use preen w/ the fert in it, so a double application at the recomended rate would be using double the fert which I wouold be learing about. Im not sure what type of fert is in the preen, Ive never checked. But im guessing its not slow release and could potentially burn and plants taking it up if double the rate is applied. Another problem is this method would be pretty time consuming, and when you are charging $50+/ MH that would get expensive.

    On almost 100% of the jobs we do that involve mulch and preen, we do it afterword and let the rain/customer water it in.
  6. Think Green

    Think Green LawnSite Silver Member
    Messages: 2,746

    I have applied snapshot and or freehand before the mulch and afterwards.
    The best results was obtained before the mulches.
    Think about the mulch absorbing the a.i. of the product before it reaches the destination of the soil line. Where is the product best effective from? I haven't yet seen results from wind seed control by mulch top applications. The roots penetrate the mulch. You do not get the added effect of control. The particulates do not always seep down to reach the soil.
    This kind of runs along the lines of preemerge granules applied to certain grasses with thatch layers. If the thatch is greater than 0.5 inches, the product is absorbed by the thatch and never is totally effective.
    On a call likes this.
  7. SpringHillTnLandscaping

    SpringHillTnLandscaping LawnSite Member
    Messages: 42

    We tend to put the preemergent under the layer of mulch so it had direct contact with the soil and hopefully seed. I would think if you put it over it wouldn't be as effective since it would get wasted and not make it to the dirt beneath the mulch. I hope that helps.

    Keeping your mulch thick is best at
  8. JimLewis

    JimLewis LawnSite Fanatic
    Messages: 6,876

    I'm not sure why you'd put a pre-emergent underneath mulch. That doesn't make sense to me. We always install it on top.

    If I am laying mulch, whatever I am laying it on is clean. I've already sprayed out the brush or weeds and removed all the brush or weeds. Then I'm adding a 2" layer of mulch on top. It's not like new seeds are going to blow in, wiggle their way down 2" through my mulch and find the soil before they start germinating. No! The weed seeds are going to blow in and start germinating on whatever they land on - namely the top of my mulch!!! So that's the area I want to protect.

    Applying pre-emergent underneath mulch is just about as effective as laying down weed barrier fabric and then installing several inches of mulch right on top of it. The weeds may not grow too deep. But they'll grow on top of that mulch - no problem.

    I don't know. Maybe it's different here in Oregon. The bark mulch we have here is pretty fine and weeds grow on it no problem. It rains all the time here. All you need is a little bit of soil, mulch, dirt, whatever - and the weed will grow on that no problem.

    I find weed fabric to be totally useless, unless you're installing something totally inorganic on top of it (e.g. river rock). And I find pre-emergents applied UNDERNEATH mulch to be equally ineffective.
  9. jvanvliet

    jvanvliet LawnSite Gold Member
    Messages: 3,944

    Right on! :clapping:
  10. grassyfras

    grassyfras LawnSite Bronze Member
    Messages: 1,475

    I'm sure the chemical leaches down into the lower levels of mulch/soil so I never mix.

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