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Aerate and slice seed or overseed?

Discussion in 'Turf Renovation' started by greenguy08, Sep 26, 2008.

  1. greenguy08

    greenguy08 LawnSite Member
    from ohio
    Messages: 99

    I have customers asking for aeration with slice seeding. Is this too much soil disturbance? Would aeration and overseeding be better? :cool2:
  2. Whitey4

    Whitey4 LawnSite Silver Member
    Messages: 2,448

    Unless the lawn is in dire straights, I'd aerate, overseed and aerate again. Slice seeding REALLY tears a lawn up. If the lawn has a decent amount of good turf, slice seeding can do more harm than good. Along with tearing up thatch, it will seriously damage good turf.

    I consider slice seeding an option only when the lawn is so bad, it is near to needing a bare dirt renovation.

    I tried using a slice seeder this year, and the debris it churned up had to be removed. That removal process also ends up removing any seed the slicer put down. I'd use a slice seeding machine like the Husky SD22 which is a Bluebird, for one pass with no seeding, after an initial aeration.Then I remove debris, and slice it again with a delta reel. By this time, depending on the depth of the slice, there won't be much viable turf left. In order to slice deeply enough to penetrate the thatch layer so that the seed gets some soil contact... the lawn is pretty much destroyed.

    I remove debris again, then broadcast seed, and slice one more time. The end result is close to a bare dirt reseeding.

    Maybe my technique is wrong, but this is what I've experienced this year with attempting to slice seed. I also won't use the seed box on the husky power rake with delta reel anymore. After making a turn, the thing would dump a pile of seed when I engaged the throttle again. So, that's why I do it as I described above. Hit a lawn with 3 passes with a power rake... the lawn is gone. It's sort of like rototilling but only an inch deep.... it removes almost all turf.
  3. LushGreenLawn

    LushGreenLawn LawnSite Silver Member
    Messages: 2,120

    It is absolutley better to aerate and slice seed. Just broadcasting the seed over the surface, even with aerating before or after, results in almost no seed germination. This has been proven over and over again by university studies.
  4. Whitey4

    Whitey4 LawnSite Silver Member
    Messages: 2,448

    I'd like to see these studies, and the conditions the tests were performed under. I know for a fact that aerating before, seeding, and aerating again WILL have results, so I know for a fact that there will indeed be more than "almost no" seed germination, but not nearly as much as slice seeding will produce, but the results are visable. The problem with slice seeding is the destruction of viable turf that occurs during the operation.
  5. LushGreenLawn

    LushGreenLawn LawnSite Silver Member
    Messages: 2,120


    What kind of seed are you using? Mabye that make a difference? Down here I am using TTTF or a TTTF/KB mix. I can never get it to germinate well unless its sliced in. My lawns look good when I'm done, with not much visable damage to the existing turf, and what is visable is gone in 1-2 weeks.
  6. bdoss123

    bdoss123 LawnSite Member
    Messages: 131

    Interesting, so you aerate before and after seeding?

    What's the effect of the second aeration, I haven't heard of this practice before.

    - BD
  7. Whitey4

    Whitey4 LawnSite Silver Member
    Messages: 2,448

    I've never used any TTTF, although I see it's use is preferred by many in the midwest, likely for it's drought tolerance once stablished. On LI, just about every lawn is smallish (in my area) and regularly irrigated. Trying to establish turf in shade is a bigger challenge here, as opposed to the wide open unirrigated spaces of the midwest.

    I use several varieties of seed, depending. Usually mixes of rye, KBG, and fine fescue. I usually try to keep the rye ratio at 15 to 25%, but sometimes settle for 30% blends. 25 rye, 50 KGB and 25 fine fesue blends are common here. (approximate numbers). The seed I used this fall was
    15% defender rye
    10% majesty II rye
    28% merit KGB
    17%serene KGB
    24% shadow chewing fesue

    I think you see less damage from slice seeding TTTF due to it's root system, deep and clumping, like rye grass. KGB and creeping red Fescue tend to get ripped up pretty good because of the rizomes they produce.

    why slit seed a lawn? Usually, because it's damaged or in distress. Grub damage, drought, fungus damage, etc, so they have shallow, weak root systems. A slice seeder will rip that stuff right outof the ground if the blades are set deeply enough to penetrate the thatch layer, especially KGB. It doesn't damage rye grass with little thatch nearly as much, and rye is similarto the TTTF root system, a bunching non rizome spreading type.

    When I do decide a lawnis bad enough for slit seeding, I get about 1 fifty five gallon bag of debris per 1k of turf. I use a delta reel on the first pass with no seed. Rake out the debris, and mow again (first thing I do is mow at 1.5") The I slice it again with the power rake with delta reel. Then I broadcast seed witha speader, and lightly scrape the ground with a leaf rake.

    this only works on the small lawns I work on. For large properties, it would be too labor intensive. By the time I do a second pass with a slit seeder, I have a LOT of bare dirt.

    For lawns that need a boost, I think annual aerating, seeding amd aerating at least one more time after over seeding provides reasonable improvement without causing damage to the existing turf.
  8. LushGreenLawn

    LushGreenLawn LawnSite Silver Member
    Messages: 2,120

    Down my way we seem to have little problem with thatch. As long as the lawns have been taken care of, it breaks down naturally, and I get almost no debris when I power seed or power rake. I have all these people that are moving down here from NY and NJ and they swear their lawn is full of thatch when there is almost none!

    I've never tried aerating before and after putting down seed. I mis-read your post at first, I thought you were seeding before and after you aerate. I'm going to practice your technique on my test plot vs. slit seeding and see if I can get close results in my neck of the woods. With my Front Mount Aerator, this would be a snap to do, as the slit seeding is ridicously time consuming when you have a lot of lawns to do.
  9. mngrassguy

    mngrassguy LawnSite Silver Member
    Messages: 2,167

    My Snapper Powerake has 10 settings. On setting #1, I will remove a whole pick-up truck of material from a 5k KB lawn and removes maybe 1/4" of thatch. Forget that nonsence.

    I've aerated and over seeded 100's of lawns over 25 years and only have failures when people don't water afterward. Even then I have "limited" success.

    Slice seeding is very labor intensive and I get the same results by just broadcasting the seed after aerating.
  10. Whitey4

    Whitey4 LawnSite Silver Member
    Messages: 2,448

    Lush (hey BTW, one of my fantasy football teams is named Leapin Leprechaun Lushes :laugh:)

    bdoss, I have no studies that would support my aerate, overseed, aearate again technique. It just seems to work, especially if I lightly rake it in as a last step, which would be similar to a drag. By drag, I mean dragging something like a piece of cyclone fence over the lawn as a last step to break up the cores and help the seed settle a bit.

    Thatch dies seem to be more if a problem up here, perhaps because of the extensive use of KGB and fine fescue... both of which tend to develop thatch more than TTTF or rye grass. The folks from NY and NJ are just so used to dealing with thatch... they don't even know what it is, but are convinced that every lawn has it! All you can do is dig up a cross section and show it to them. Either they are trainable, or they aren't.

    I'd rather be patient and aerate and overseed for a few years than rip up a fairly decent lawn with slice seeding.... I prefer to slice seed only lawns in dire condition.

    That is part of my problem with slice seeding... the thatch tends to be heavy, and I have to slice deeply. It really tears up the turf.

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