Clay help

Discussion in 'Landscape Architecture and Design' started by Haulin' Grass, Oct 10, 2007.

  1. Haulin' Grass

    Haulin' Grass LawnSite Member
    from CT
    Messages: 55

    I had a customer call me wanting a new lawn put in. He mentioned that there is about 1 in of top soil over clay. I told him he needs more(top soil) brought in and reseed. I know I should mix sand into the clay but don't know how much. A couple inches then till it in and add top soil ??
  2. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    If you could till in some sandy topsoil would be great.
    You can just spread 3 inches of sandy topsoil with a skidster and take your chances on whether and where 'puddling' may occur but breaking up the hardpan and having a better distribution of soil is better.
    When you think about clay soils you can think about a 3 inch root zone with good drainage (sandy topsoil) with great water retention at the bottom (clay). If the root zone is too shallow, then its like a claypot without a hole. That area becomes anaerobic and compacted (what we call 'puddled') and the grass dies time after time. That is why I like to till and prepare the seed bed with an iron garden rake.
    If you can charge the time for the job, the more tilling the better IMO. Unless you are going to try and mix thoroughly the sand and the clay you want plenty of OM. Even if you do mix thoroughly you want plenty of OM.
    Goodluck and don't be afraid to experiment. You have clay so it is pretty hard to make things worse :)
  3. Grn Mtn

    Grn Mtn LawnSite Senior Member
    Messages: 863

    gypsum pellets will break down the clay , you buy them in 50# bags, have compost delivered and use a tiller as deep as you can.
  4. ballstar

    ballstar Banned
    Messages: 37

    Too much tilling means creating essentially more clay. Basic soil science class.
  5. Rtom45

    Rtom45 LawnSite Senior Member
    Messages: 456

    Unfortunately, adding sandy topsoil over a clay base does not cure the problem, it complicates it. Studies have shown that your soil must be at least 60% sand before you benefit from it. Up until that point, adding sand to a clay soil is detrimental. The current recommendation is to add compost or a soil compost mixture. It would be best to apply some of this, till it into the clay, then add some more and finish grade.

    SOUTHERNGREENSCAPES LawnSite Senior Member
    Messages: 763

    i don't know if you have ti up there, but the ideal media to add in this situation is pine fines or what some nurserys call soil conditioner. It is very small pieces of pine bark. Pine bark takes years to break down and will allow great drainage. of course this is ideal and if you do the math as to how much you would need to get 1 inch of coverage before tilling in, 9 times out of 10 is it not cost feasible.
  7. BrandonV

    BrandonV LawnSite Platinum Member
    Messages: 4,631

    clay is great! just lime the heck out of it, you'll need less water and if you till it prep it right you can have a great stand of grass.
  8. LB1234

    LB1234 LawnSite Gold Member
    Messages: 3,208

    For clay soils here we just add organic matter to it and till it. We have the ability to obtain bulk compost and it seems to break down the clay pretty effectively. Of course you should also follow up with aeration every year and if its really really bad you could topdress with a thin layer of organic matter which will eventually start changing the clay over.

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