my fall pre-emergent failed.

Discussion in 'Pesticide & Herbicide Application' started by inzane, Feb 13, 2013.

  1. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,798

    It is possible you are seeing the perennial form of annual bluegrass--some of it survives the winter--it persisted through the winter, instead of arising from seed.
    I don't know about the henbit.
    Are you saying you used pendimethalin, and then prodiamine? At label rate?
    Was your spreader calibrated accurately? Was the green color uniform in the fall? No skips or stripes?
    What was the condition before you started? You may be looking at 95 percent control--if Poa was heavy in the previous year.
    What were them high temps when you treated? How do this compare with university recommendations for your state? Dealer's suggestions?
  2. RAlmaroad

    RAlmaroad LawnSite Silver Member
    from SC
    Messages: 2,257

    I'm going to go way out on the limb and suggest that: In order for a pre-em to be beneficial it must be applied BEFORE a seed germinates and send out it first hair root. After that hair root get established, and rooted your pre-em may not be strong enough to fry the root. Dimension will have up to about 3 weeks to kill a weed after it has developed the root. Don't know about the stuff you got from Home Depot, but probably somewhat inferior to the John Deere stuff. On that Bermuda if temps are not too hot (below daytime temps of 85) then try Simazine or the 0-0-7 Dimension. Henbit is an easy weed to eradicate but difficult to get all of the seed. Another suggestion is to get the pre-em to the soil surface by watering it in within 24 hours. Of course a good rain will do that for you. I first though that IF sandy soil was prevalent, then the pre-em may have leached past the weed seed before it had sprouted the hair root. Timing is everything in dealing with pre-em. I'd deep six that Home Depot stuff; stick with name brand (Gallery if you could spray it earlier in the season) or Dimension. Stonewall (Barricade) has less pruning (Which is what a pre-emergent does), might be less effective on the clay soil.
    I think you may have just been a bit late and a less active product. Pre-ems tend to diminish in activity in 6 weeks (less with higher amounts of rainfall) especially using it as a split application. So try, full strength a little earlier and Simazine 6 weeks later to kill off any winter developing weeds that have blown in from neighbors.
    Riggs may be right when he mentioned the perennial blue grass. It sure looks like Poa when it first spouts.
    Fall is a tough month in more ways than one. Weeds have toughened up also.
    Has that schedule been successful on these properties before last fall?
    Stuff happens, acknowledge it, record it and make changes if needed.
  3. ArTurf

    ArTurf LawnSite Platinum Member
    Male, from Ark
    Messages: 4,471

    I have good success with Simazine in the fall.
  4. turfmd101

    turfmd101 LawnSite Bronze Member
    Messages: 1,376

    A seeds first gulps of life,,, must be invaded with AI. For death to occur for the seed. It germinates before application, not probably going to die. Dormant while AI is surrounding it. Not much of a issue, it will survive the application and probably germinate at some time. Thats why timing is so important.
    Also, go full rate on the first app. Also make sure you'll need the app

    .I know in central Florida, a bunch of pre-m went down in the fall. Followed by a super drought. I guess too many people over irrigate. You know who you are because you had Brown Patch, in a warm super dry season. " WHAT THE".
    Posted via Mobile Device
  5. ted putnam

    ted putnam LawnSite Platinum Member
    Messages: 4,741

    Something to think about also is...How long have those 2 lawns been on your program. Your lawn has probably been on your program for at least a couple of years. Lawns, especially first season lawns that were weed patches when you started are nothing but a "seed bank". ArTurf is correct, once last falls pre has broken down and we have a few warm days, weeds from that seed bank germinate.

    It takes a couple of years for that seed bank to be depleted. This is what I have determined from some I have done in past years that fit your description.(at least thats what it sounds like from what you are describing.)

    Not failure. Just intense weed pressure and 4 months with no pre-emergent and lots of weed seeds that are still viable.
  6. macgyver_GA

    macgyver_GA LawnSite Senior Member
    Messages: 826

    Good point.
  7. WestGaPineStraw

    WestGaPineStraw LawnSite Senior Member
    Messages: 765

    Dimension this time of year is a waste of money.

    Op, you are never gonna have 100% control on weeds in this area. That's why from sept - may we run a post emergent herbicide every round to catch the small boogers that pop through.
    Posted via Mobile Device
  8. inzane

    inzane LawnSite Silver Member
    Messages: 2,478

    i thought mabee it was the fact that these 2 yards are never watered unless it rains, that 2nd treatment in oct, we went a while without rain. i rememeber having to go out and water my lawn the next day or so after the treatment because it was the only way because there was no rain in the forcast for a while. and i know for a fact that the one rental didn't get the stonewall watered in, the other one.. (my moms lawn) she doesn't think she did, but doesn't remember. lol. she never pays attention to the special instructions i leave.

    however, these 2 lawns haven't been on a program in a while, so i guess that could be it too.
  9. turfmd101

    turfmd101 LawnSite Bronze Member
    Messages: 1,376

    It's all made possible, because the planets always growing native ground covers,,, it.. will continue doing so until the end of time. You will never be able to stop your practices. You can only see whatsa comin,,, then pick your ongoing, developing, strategies.

    Like surfing... In order to get positioned for set waves. You have be able to read the horizon crests of waves forming coming to shore. Then understand how it will all play out once the waves reach you. Then you have moved to a spot, where you knew a wave would break because you read the ocean movement miles out. If not. You miss lots of good waves and there's just alot of aimless paddling going on.
    Posted via Mobile Device
  10. inzane

    inzane LawnSite Silver Member
    Messages: 2,478

    i wanted to use barricade for round #1 then dimension for the round 2 but i wanted to do something different since i used barricade in the fall. and also when i went to find liquid barricade all they had was the WDG.. do they make that in liquid form? i highly doubt my sprayer will handle anything but liquid herbicides. shurflo electric pump with jet agitation. I had to many problems trying to run that crap through similar pumps when i worked at orkin long time ago. I definetly have alot of work to do on my program, and plenty of time to figure it out. its not something i sell much of anyway.. looks like i'm getting more mowing customers than anything.


Share This Page