Pine shavings/sawdust mulch?

Discussion in 'Gardening & Plant Propagation' started by Randy Rooster, Nov 26, 2006.

  1. Randy Rooster

    Randy Rooster Well-Known Member Supporter

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    I have always heard not to use it, but was reading a book on gardening the other day that they advocated it and said just use some extra fertilizer on your plants. I have a very good supply that I would like to use on my blue berry plants but dont know if I should if it will hurt them.
     
  2. Marcia in MT

    Marcia in MT Well-Known Member Supporter

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    Mulch with a high cellulose component (sawdust is almost *all* cellulose) can create a temporary nitrogen deficiency in the soil until it's all broken down. The soil life that breaks down the lignin in the cellulose uses N and ties it up; it becomes available again after the microbes die. So, if you add some extra N to the mulch, it should be fine. Something like alfalfa pellets, for example.

    Some sawdust can be toxic -- walnut -- but I've never had a problem with pine and mixed species shavings/sawdust. I turn it under, mulch paths and plants, and use it in compost.

    The only N deficiency I've ever had was when I planted corn in an area where tree leaves hadn't finished -- or hardly started! -- composting in a layer in the soil. I saw typical deficiency symptoms until the roots grew through the leaf layer and contacted regular soil.
     

  3. MoBarger

    MoBarger Goat's Milk soap for sale

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    Pine is good for acid-loving plants like your blueberries and rhodos and azaleas. And roses.

    But remember that the process of breaking the wood down eats Nitrogen in your soil so you will have to add that somehow. I usually add winter bedding from the chicken coops (poop+pine shavings) to the blueberries in the spring after pruning. That way it is a good mix. Blueberries aren't complaining! :)
     
  4. MoBarger

    MoBarger Goat's Milk soap for sale

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    No wonder, corn is super-hungry for N! :)
     
  5. Marcia in MT

    Marcia in MT Well-Known Member Supporter

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    Originally Posted by Marcia in MT
    "The only N deficiency I've ever had was when I planted corn in an area where tree leaves hadn't finished "

    "No wonder, corn is super-hungry for N! "

    That's what made it so interesting, and why I left it instead of treating it: I'd never seen a true-blue, full-blown N deficiency before, and I wanted to see what would happen if I left it. And I found that it could grow out of it (literally), but it left the corn a little stunted and perhaps not quite as productive. If I ever hit that layer again while planting, I'll be sure to treat it for N deficiency *before* it appears!
     
  6. Jeslik

    Jeslik Well-Known Member

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    Apologies - didn't mean to bring a dead thread back to life. I was catching up on my forum reading, and didn't notice how far back I'd gotten.
     
  7. Steve L.

    Steve L. Well-Known Member

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    I extended some garden rows once (onions), on a very gravel, low OM soil. I thought I’d be ‘smart’ and incorporate some sawdust to bring up the OM in that area. The difference between the the sawdust area and the ‘good’ garden soil was amazing! The sawdust onions were only about one third the size.

    Jeslik, It’s good to drag these older threads up every now and then. Saves the rest of us a lot of typing.
     
  8. Wildfire_Jewel

    Wildfire_Jewel Well-Known Member Supporter

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    I needed to see this. We use pine shavings in the pans under our rabbits and this has all been dumped onto the garden area and will be tilled in come spring. I will be sure to add some N now to keep things balanced out
    THANKS!!
    Melissa
     
  9. Steve L.

    Steve L. Well-Known Member

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    Actually, Melissa, the rabbit droppings may supply enough N to balance the needs of the shavings. That N won't be available for your plants, though, until the shavings have decomposed. It will be available at some later time. Think of it as 'money in the bank', rather than fertilizer for at least the first part of the growing season. In the garden I mentioned above, I routinely used sawdust horse bedding for mulch, and had no problems.
     
  10. GeorgiaberryM

    GeorgiaberryM Well-Known Member

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    The rabbit poop should be suffecient for the N. When I've seen sawdust used on blueberries the effects were terrible, but the farm had really piled it on. Smaller amounts should be fine. There are other problems associated with sawdust besides just N depletion though. The tars present in the heartwood are highly concentrated and decomposition is highly exothermal. There are some mushrooms that will live in the sawdust that are edible, if you can find the plugs. Mushrooms would turn that sawdust into some real premium stuff. I would also consider composting it by adding some leaves, weeds, grass clippings, more poop, etc. and then use that. You can use it straight, just don't use too much. If you use it like that then I would experiment with a small area before doing large sections.

    Husband o'G
     
  11. WisJim

    WisJim Well-Known Member Supporter

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    We have on occassion used a lot of mixed pine and hardwood sawdust (like the couple of years when a neighbor had a sawmill come in to saw logs for him, and he brought us a couple of large dump truck loads of sawdust, enough to cover our garden 6 inches deep. We had no noticable problems AT ALL! I was a bit surprised, but it may have been due to our already excellent fertility.
     
  12. GrannySue_in_IL

    GrannySue_in_IL Member

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    I've never had a problem... I used it as a 3-inch layer in all of my lasagna beds. I did use a little lime on the ones that need a little less acid though.

    Tomatoes and such Love the extra acid from pine....
     
  13. Paquebot

    Paquebot Well-Known Member

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    No matter what wood is used or what form or how, it's not being done for its nutritional value. Plain dry wood chips or sawdust have just over 2 pounds of NPK per 2,000 pounds, a ton. (One can have that much in less than 200 pounds of leaves.) It is strictly a temporary soil conditioner when incorporated into the soil. There, it absorbs nitrogen from the soil in order to break down. In the case of using it from under the rabbit hutch, it will likely have absorbed sufficient nitrogen to avoid that problem. That from horse stables may also have enough. If there is no nitrogen in the material to be worked into the soil, 22-0-0 ammonium sulfate or 45-0-0 urea may be mixed with it. That will supply the nitrogen required to break it down rather than removing it from the soil. When used strictly as a surface mulch, woody material obtains its nitrogen from the air and usually is not a problem to growing plants.

    Martin