1. Missed the live Ask the Expert event?
    Catch up on the conversation with Ken Hutcheson, President of U.S. Lawns, in the Franchising forum.

    Dismiss Notice


Discussion in 'Turf Renovation' started by Smallaxe, Sep 27, 2011.

  1. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    There seems to be a real problem determining what thatch is... Conversations about thatch have become impossible because one person is thinking grass clippings and another is thinking, living and dead roots and stems growing in a tangled mess above the surface of the soil...

    This dense layer is typically hydrophobic and keeps the ferts and water at or near the surface, thus perpetuating the problem with roots continuing to grow upwards where the N is...
    It is this kind of thatch that is man-made and it it this kind of thatch that aeration is designed to overcome the problems of...

    Question is : What do we call grass clippings and are they even a problem?
  2. ArenaLandscaping

    ArenaLandscaping LawnSite Member
    Messages: 230

    Thatch is a build-up of organic matter which can include, dead grass leaves, stems, stolons, rhizomes and overcrowded grass roots and lateral weed growth. Thatch can stifle the growth and health of grass or turf. Removing the thatch helps the grass by encouraging it to thicken up and also makes it stronger and less susceptible to disease. Reducing thatch levels increases the levels of water, air and nutrients that can get through to the root zone of the grass plants. Significant thatch problems in lawns can cause diseases and can encourage moss to grow in the areas where grass has died. A by-product of scarifying or de-thatching is that moss is also removed, and depending on how deep the scarifying blades are set, root cutting can also occur, and this in turn helps grass to thicken up over time. Scarifying is normally carried out in autumn or spring. When scarifying or de-thatching not all thatch should be removed as a small amount of thatch is beneficial to the lawn. A lawn that has excessive thatch may feel spongy when trod upon. After removing thatch, it can be swept or raked up using a lawn sweeper.
  3. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    Vertical mower/dethatcher destructive:

    "Thatch may be torn out with a dethatcher or vertical mower, but will most likely return unless the cause is corrected. Mechanical dethatching is also very destructive to the lawn because roots are in thatch instead of soil, so plants tear out easily. Overseeding is usually required afterwards. For this reason, it's best to tear out thatch in late August for optimum reseeding timing. "

    no real attention paid to grass leaves as wikipedia states
    "Thatch is a layer of living and dead organic matter that occurs between the green matter and the soil surface....The primary component of thatch is turfgrass stems and roots. It accumulates as these plant parts buildup faster than they breakdown."

    Regardless, is it acceptable to call a layer of grass clippings "Thatch" and should it be regarded and treated the same was as the living and dead roots and stems??
  4. JDiepstra

    JDiepstra LawnSite Bronze Member
    Messages: 1,511

    Wow youre really making a big deal about this! All that stuff between the grass blade and the soil..... Thats thatch.
  5. ArenaLandscaping

    ArenaLandscaping LawnSite Member
    Messages: 230

    I believe it is acceptable to say that grass clipping can be regarded as thatch. Over time they add to the thatch layer/buildup.
  6. olcllc

    olcllc LawnSite Member
    Messages: 202

    Well said!!!:clapping:
  7. MJS

    MJS LawnSite Bronze Member
    Messages: 1,316

    You would be surprised, that has rarely been my experience. Unless the clippings are excessively long or thick, they disintegrate and are absorbed, at least partially, as nitrogen by the grass that is growing. Clippings are almost never a cause of excess thatch.
  8. ArenaLandscaping

    ArenaLandscaping LawnSite Member
    Messages: 230

    Grass clippings are not the cause of thatch, they add to the thatch layer "over time". An accumulation of wet grass clipping that do not have enough time to decompose over time or in between cuts will be left in the thatch layer. It all depends on the mowing practices.
  9. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    Unfortunately, none of these comments relate to the "University Extension" articles that have been posted recently, including the one in this thread...

    Don't Overthink this... we're just looking for a definition of 'thatch' that gives us a point of impact on a cause and solution... No big deal... :)
  10. Darryl G

    Darryl G Inactive
    Messages: 9,500

    I call grass clipping grass clippings. What else would you call them?

    I rarely see any significant thatch layer where I am. I will do a tine rake dethatching on some lawns in the spring, but it's mostly to comb out some of the dead grass and matted leaves and twigs. If i can easily get my finger down to bare soil, I consider the thatch layer insignificant and don't worry about it. I think that if you have to dig and wiggle your finger to get it through to soil, that's when it could be a problem. I have never used a power dethatcher though and have never felt the need for one.

Share This Page