Top Dresser/Overseeder

Discussion in 'Turf Renovation' started by RLS24, Aug 8, 2012.

  1. RLS24

    RLS24 LawnSite Bronze Member
    Messages: 1,603

    I'm thinking with the extreme dry conditions this summer, that come fall offering top dressing/overseeding will be a fairly marketable service for me. This is also a new service for me (to do in large quantities). When we've done it in the last its basically been a job-by-job deal and we would just do with the old fashioned way of hand-sprinkling a topsoil/compost mix and then going over it with the drop spreader with seed and starter fert. If we do this on a larger scale, thats gonna be too time consuming, so I'm looking for other options. I guess what I want to know, is whats the difference between a topdresser and an overseeder, and also whats the difference between the types? I've used a slit-seeder (or lawn renovator some call it I think), but what about these ones that attach to the front of a power rake vs these things that look like a giant wheelbarrow with some sort of drop spreader mechanism on them? Could I, in theory, just use a heavy duty drop spreader? or would the topsoil/compost mix just be too much for that to handle?
  2. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    A slit-seeder cuts open the ground to theoretically drop seed below the surface, and will not be of much value in spreading compost...

    A topdresser in theory, broadcasts large volumes of material uniformly above the surface of the ground...

    You could pre-mix your seed and compost together then broadcast on top of the surface... this of course, will depend on the environment in which the seed is placed, as to whether it will germinate or not... full sun sandy locations would not be ideal for this method, for example...

    I would take the time to do the best job possible if shortcuts put the project at risk... :)
  3. turfcobob

    turfcobob LawnSite Senior Member
    Messages: 878

    A top dresser is a machine that spreads "topdressing" over the ground evenly. Now topdressing can be anything from plain ole dirt to sand and anything in between. Most commonly it is a blend of dirt, sand and other organic material such as compost or peat. All the machine (topdresser) does is spread it out.

    An overseeder is a machine that will seed over an existing lawn. Some cut slits into the lawn, some just disturb the top or thatch layer and some just drop seed. The goal of a good quality overseeder is to cut through the thatch and place the seed onto the mineral soil so it will grow. This is best done using an overseeder with "slicing blades". Slicing Blades are steel blades that are fixed and cut into the soil as the reel they are attached to spins. This is by far the best method of cutting through the thatch layer to get good seed / soil contact. Some units out there are Dethatchers that have seed boxes attached to them. While they may claim to be overseeders they usually have flail blades that are designed to swing away when they hit the thatch layer. These type blades and spring blades do a marginal job of getting through the thatch layer and to the dirt (mineral soil)

    You can see these machines in action at
  4. RLS24

    RLS24 LawnSite Bronze Member
    Messages: 1,603

    So basically, to achieve what I'm trying to do, it seems like I need a few different machines (or come up with one that doesnt exist and make millions? lol). I guess this subject really shows that I'm more of an ornamental landscaper/lawn cutter than a turf care professional...

    This is pretty much what most lawns around here look like, and HAVE looked like for 6 to 8 weeks....

    I was thinking the best course of action would be to thoroughly de-thatch the lawn (either with the JRCO rake on my mower or an actual power rake), obviously then clean the thatch up, then put down a topsoil/compost mix that my mulch/topsoil supplier sells, add seed and starter fert to it and call it a day. I'm not sure what order that last part should be in, but you get the idea. A friend of mine has one of those slit-seeders (or verticutters whatever you choose to call it) and I've used it before, and I'm not so sure that the blades would actually cut into the ground, I mean the ground here is ROCK hard. When we were trimming bushes the other day and raking up the clippings, it sounded like you were dragging the rake over a piece of plywood, and I've never heard it like that before....anyway I've also read that doing a core aeration before the seeding could be beneficial, but again the ground is so hard that I'm not sure the machine would really be able to work the way it is intended to.
  5. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    That is how our unirrigated lawns have looked since the 4th of July Holiday... I would not dethatch the turf until it has fully recovered... You might also consider leaving the organic material on the soil surface as opposed to exposing bare soil to the elements...

    If you actually do topdress with compost, you really don't have to be concerned about slow decomposition... you may instead experience, vastly improved soil structure and water holding capacity...
    As one who runs beef onto grass-only pasture, I've got to say that I actually cringe at the thought of removing 'thatch' cover from those soils...

    ...something to think about... :)
  6. turfcobob

    turfcobob LawnSite Senior Member
    Messages: 878

    If I were to tackle that lawn here is what I would do. First has this ground been growing good grass in the past? If so why try to amend it with topdressing. Why not find out what nutrients are needed and fertilize life into the new lawn? Thatch can be a bigger problem if it is more than a half inch thick it should be removed.
    Sept 1
    1.Mow as short as possible using the JRCO thatch remover to get as much of the dead stuff gone as possible. Thatch will only be a problem if it is more than a half inch thick.
    2. Aerate until you get 12 to 15 holes per sq ft. Even if you are just getting small holes you are opening up bare spots of soil for the seed to get to.
    3. Slit seed the lawn in two directions. Best to go at 45 degree angle to the first pass.
    4. Water as needed for new grass seeding.
    5. Fertilize and water in when the grass gets it's first mowing. If you fert too early you will be feeding the competition to the new grass better to wait till the new lawn is growing so it gets the most benefit.
    Note: I usually put in 30% rye grass seed as it will be up in a week. This early growth makes the owners happy to see grass so soon and it will help shade the blue or fescue as it comes up a couple weeks later.

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