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Going the extra mile

Discussion in 'Florida Lawn Care Forum' started by South Florida Lawns, Aug 10, 2011.

  1. South Florida Lawns

    South Florida Lawns LawnSite Platinum Member
    from usa
    Messages: 4,784

    Anybody use a pre emergent before laying new sod? I got some Surflan and was planning on putting that down after burn out/tear out, to prevent any new weeds on a particular weedy lawn. Don't want any chances of seeds or neighbors weeds germinating on the new lawn.
  2. Keith

    Keith LawnSite Gold Member
    Messages: 3,979

    Take a look at the label.

    Surflan A.S. may be applied as a preemergence treatment for control
    of annual grasses and certain broadleaf weeds in established warm season turf including bahiagrass, bermudagrass, buffalograss,
    centipedegrass, St. Augustinegrass and zoysiagrass
    or established
    tall fescue growing in warm season areas. Established turf is defined
    as a dense turf having a well-anchored root system and healthy,
    vigorous top growth.

    To avoid possible injury, do not apply Surflan A.S. to:
    ° Cool season turfgrass species.
    ° Golf course putting greens or tees or lawns containing dichondra
    or cool season turfgrass species.
    ° Newly sprigged or sodded areas of bermudagrass, St.
    Augustinegrass, centipedegrass, or zoysiagrass until these turfs
    are well-established and have well-anchored root systems.

    ° Newly hydromulched areas of bermudagrass until such areas are
    ° Bermudagrass variety “Sun Turf” when tank mixed with atrazine
  3. South Florida Lawns

    South Florida Lawns LawnSite Platinum Member
    from usa
    Messages: 4,784

    wow thanks for all that info.
  4. bugsNbows

    bugsNbows LawnSite Member
    Messages: 170

    Pre-emergents on new sod can invite disaster.
  5. Ric

    Ric LawnSite Fanatic
    Messages: 11,969


    I am not sure how I want to say this but I mean it General terms not directed at any one. BUT the trouble in our industry is lack on education. Two simple theories butt heads here. 1st Most all residential Pre-emerge works by a vapor barrier that kills the Cingular root just after germination. 2nd That same hair root on new sod is killed also.

    Universities are for ever testing two school of thinking about the CHEMICAL ROOT PRUINING of pre-emerge. One Theory says good and the other says bad. On St Augustine I believe it is bad but because of many great Post emerges being taken off the market I chose the lesser of two evils.
  6. Ric would you mind explaining root pruning?
  7. Ric

    Ric LawnSite Fanatic
    Messages: 11,969

    Chemical Root Pruning.

    The quick answer is there are two major schools of thought about the effects of Pre emerge. One is of course the value of being weed free hopefully without any Ill effects to desirable turf. The other believes that the pre emerge stunts desirable turf's new roots and therefore cause a weaker turf because root extension and mass is considered imperative to healthy turf.
  8. Greg Amann

    Greg Amann LawnSite Member
    Messages: 162

    Root pruning in St. Augustine causes looping.
  9. greendoctor

    greendoctor LawnSite Fanatic
    Messages: 9,999

    Root pruning on any stolon forming grass is a problem. That is when the roots that normally descend into the soil from each node along the length of the stolong are prohibited from growing. Most herbicides that are strictly preemergent such as Dimension and DNA(dinitroaniline) compounds targeting grass do not differentiate between a st augustine root or a crabgrass root. The health of a st augustine lawn is highly dependent on roots tacked down to soil, uptaking water and nutrients. The net effect of a root pruning herbicide on a warm season grass can be thinning and poor overall health. Oddly enough, this sets up the ideal conditions for weeds to take over once the preemergent herbicide is past its effective half life. Specticle is a new preemergent herbicide just released this past year. It is a severe root pruner. Golf courses here got into all kinds of trouble when this product was applied to turf stressed from a combination of low fertility, cold, lack of sun, and poorly drained soil. It actually stunted and thinned established turf.

    If a root pruning preemergent goes anywhere near a lawn that is newly sodded, sprigged or plugged, net effect is a failure of the lawn to establish. Having said this, I am not suggesting to simply throw sod over a known weed party. There is a third way that goes the extra mile, but will quickly weed out the kind of client that you probably would not want their money anyway. The very ones that want a fast and cheap fix are just as quick to hang you over problems caused by a fast and cheap job. If reestablishment of a weed infested lawn is desired, start the process early in the growing season. Throw some cheap, non slow release complete fertilizer over the area and start watering. What you want is to make everything grow, including the weeds. Then, fry it. My usual turf area kill out mix involves RoundUp, Certainty and Garlon. Once this set of weeds are killed, it is time to cultivate the ground and resume watering. The next set of weeds that come up should only need RoundUp. Then you water again and kill what comes up. This will take about 2-3 months to do. I would have no issues with putting down new grass over an area prepared in this manner. I have seen many one time kills done with either plain glyphosate or Quickpoo(misspelling intentional, because that is what it is), have all kinds of weeds come through the new grass.
  10. Ric

    Ric LawnSite Fanatic
    Messages: 11,969


    Since I work mostly with St Augustine turf, I am of the Post Emerge School and won't blanket apply pre emerge. I will in special cases use a Pre emerge on a spot treatment that I might have trouble with.


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