Treated Lumber for Raised Garden

Discussion in 'Landscape Architecture and Design' started by chevytrucks84, Mar 8, 2006.

  1. chevytrucks84

    chevytrucks84 LawnSite Member
    Messages: 147

    I have a customer interested in a raised vegtable garden and was wondering if there was a problem with using treated lumber as the border (more economical) or use retaining wall stone....Thanks in advance for the help
  2. sheshovel

    sheshovel LawnSite Fanatic
    Messages: 5,112

    They say the chemicals in the treated lumber leaches into the go with stone if you can.
  3. Dreams To Designs

    Dreams To Designs LawnSite Bronze Member
    Messages: 1,406

    What is the lumber treated with? The new treatment on lumber is not supposed to be bad for you, but the old CCA had an arsenic compound that can be dangerous. With that amount of ground contact and moisture, your raised bed will be temporary, just how long is quite variable. If you are going to make a raised bed out of 2"x? material, add a seating cap to be able to sit and work from the edges if you build it tall enough to be comfortable. Not more than 5' across can typically be accessed from both side while seated. If you do use retain wall block and build it right, it will last virtually forever and with a cap stone on top makes a great place to sit and work. You should line the inside of the block with a geo fabric to keep any soil from coming through the block seams.

    My choice would be wall stone, as it is more attractive, virtually permanent & more durable, has a comfortable seat to work from with just the block or finished off with a cap stone and many styles and colors to blend with the landscape. There may be an issue with lime leaching from the concrete into the garden soil, bit I have never read of any documented research on that.

  4. chevytrucks84

    chevytrucks84 LawnSite Member
    Messages: 147

    Thanks for the replies. I know i would rather go with stone for many of the reasons you mentioned and hopefully i can sell the customer on that also
    Thanks again
  5. Dreams To Designs

    Dreams To Designs LawnSite Bronze Member
    Messages: 1,406

  6. PaulJ

    PaulJ LawnSite Bronze Member
    Messages: 1,774

    [​IMG][/IMG]I built a 8'x12' raised bed for a customer a few years ago and it''s still in good shape. I use treated landscape timbers. I asked the extension specialists then about the chemical issue and they informed me that the stuff used to treat the wood now is not harmful to the soil or any plants grown in the soil.

  7. PaulJ

    PaulJ LawnSite Bronze Member
    Messages: 1,774

  8. drsogr

    drsogr LawnSite Bronze Member
    Messages: 1,275

    Us kansasans don't worry about stuff like that. I have railroad ties for my garden border.
  9. LB1234

    LB1234 LawnSite Gold Member
    Messages: 3,208

    Just because it isn't harmful to plants doesn't mean it isn't harmful to humans. Assuming you would eat the fruit/veg etc.

    If you use the PT 6x6's (or whatever else) you should line the inside with plastic (preferred) or metal and it will help prevent the chemical from leaching into the soil for the plants to take up. Just make sure you don't line the bottom, cause you need soil draingage...think about lining the bottom with some stone and placing a heavy duty landscape fabric over it for good drainage...if warranted, needed, desired, etc.
  10. 1MajorTom

    1MajorTom Former Moderator
    Messages: 6,073

    You either resize the picture down a small tad, or else rename the picture. If you delete the original picture in your cp attachment area, it will not show up anymore where you had originally posted it.

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