Seed under dead grass or on top?

Discussion in 'Turf Renovation' started by RigglePLC, Oct 30, 2018.

  1. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 15,817

    I wanted to test whether seed would germinate better under dead grass clippings or if the seed were sown on top of dead grass clippings. I placed the seed under or over fresh green grass clippings. For untreated comparison on bare soil. I counted out 20 seeds. The containers are about 2 square inches. Experiments have been moved inside.
    Results in about 10 days. Seed types were perennial rye, tall fescue and fine fescue.

  2. Delmarva Keith

    Delmarva Keith LawnSite Senior Member
    Messages: 668

    Great experiment. My only observation would be that in “nature” the sun and wind tend to dry the clippings in a day or two at the most and I wonder if that may change the result. Are the clippings drying out indoors?
  3. KerbDMK

    KerbDMK LawnSite Bronze Member
    Messages: 1,470

    This experiment may more closely resemble a rainy period, or a homeowner that may be giving a lot of water. There also could be a difference in mulched vs long clippings. There are just too many variables to consider at one time, especially for a backyard scientist. I think the results of this experiment, just like most that any of us could do at home, will be very interesting even if all the possible real-world variables cannot be considered in just one experiment.
    DXN1EL and hort101 like this.
  4. OakNut

    OakNut LawnSite Platinum Member
    Messages: 4,502

    I dunno... I've never seen results better than "Meh" if you don't cover the seed (placed on bare soil) with a top dressing of some sort.

    I'm FAR from an expert on seeding lawns, but for bare spots in my lawn, I mix peat moss and some sort of cheap, bagged topsoil that's not damp and clumpy. I mix it up in a wheelbarrow, then toss it out across the grass seed to cover it.

    It always grows and grows fast.
    I recently had to repair an area about 30'x30' in my back yard after raccoons tore up the lawn looking for grubs and after raking away all the grass, that's how I did it. Grass started peeking out in 4 days.

    The following week, I tossed some seed out onto a few thin spots in the new growth and at the same time, I "over seeded" the rest of the lawn.
    (the lawn is just a mix of grass and weeds)

    Over the following three WEEKS I kept an eye on the over seeded areas and while I have to consider the lower temps that occurred after the over seeding, there's really VERY little new growth from seed that is just tossed onto the ground. (and we had a downpour after I applied it, so it did get some help getting worked down to soil level)

    I've never understood over seeding - seems like you're just throwing a ton of seed down in the hope that a fraction of it actually grows.
    May as well be throwing as many pennies or dimes down along with it considering the money wasted.
  5. KerbDMK

    KerbDMK LawnSite Bronze Member
    Messages: 1,470

    Bare spots can be problematic and I also get better results if I use some soil or work the seed into the soil on the bare spots.

    In the following photos, I killed the lawn, cut the dead grass short, fluffed it up with my blower, spread fertilizer and seed, then watered. 70/30 prg/kbg. I confess that I did lightly rake the bare spot where the tree was, but no soil, compost, or aeration was used for the rest of renovation.

    Friday, August 31, 2018

    front reno 1 - Copy.jpg

    Wednesday, October 24, 2018

    front reno 2 - Copy.jpg
    Delmarva Keith and hort101 like this.
  6. OP

    RigglePLC LawnSite Fanatic
    Messages: 15,817

    Most excellent! You are amazing, Kerb.
    hort101 likes this.
  7. KerbDMK

    KerbDMK LawnSite Bronze Member
    Messages: 1,470

    Thanks Riggle, I'm looking forward to seeing the results of this experiment.
  8. Hineline

    Hineline LawnSite Senior Member
    Messages: 940

    I've used grass clippings as mulch several times with great success. No soil prep, just spread seed on hard dirt and piled grass clipping over the seed. Works great in cooler, wetter weather. I believe the acids in the clippings help initiate germination. I've also seen new germinations get scalded during extreme heat due to what I believe was rapid decomposition of dead grass stubble in an overseeding.
    That Guy Gary, hort101 and KerbDMK like this.
  9. Delmarva Keith

    Delmarva Keith LawnSite Senior Member
    Messages: 668

    A good topdressing after seed is great but the issue is it’s generally not practical for large areas (I’d say for me at least, more than a few thousand sq ft and I’m not doing it, been there, I’m too old for that crap). Just throwing seed at the right time of year on the ground for an overseed works. Prepping the ground with some form of dethatching / aerating works even better. Rolling it in afterwards works even better. So on and on.

    Riggle is answering questions I’ve wondered about for a while — better to mow before or after the seed goes down. Better to bag or does it matter for an overseed. For areas with many, many sq ft, yeah, the answers make a big difference.
    hort101 and KerbDMK like this.
  10. KerbDMK

    KerbDMK LawnSite Bronze Member
    Messages: 1,470

    I strongly agree with Delmarva Keith, and I’ve been successful using dead clippings like Hineline. I’ve been successful mowing green clippings into overseedings too, but I’ve also had some trouble spots or thin spots in many seedings and sometimes not known for sure what causes them.

    I wonder if heavy clippings or compost can sometimes cause or encourage dampening off problems, and I wonder if my thin spots and less successful areas of seedings can be caused by seemingly insignificant micro differences in environmental conditions from one area to the next.

    I’m always curious what causes these problems and I enjoy learning about these mysteries.
    hort101 likes this.

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