Plywood sawdust as mulch?

Sawdust in general is bad mulch because it takes nitrogen out of the soil as it decays. I am guessing that hardwood mulch is okay because it takes so much longer to decay, but don't really know that.

Nor do I have any idea if plywood dust is worse than wood dust.

I have been spreading my sawdust in the garden area between the raised beds (NOT in the raised beds!) and the grass is just as green as anywhere else for 2 years now. If it will hurt flowers or shrubs, I don't know but I would doubt it. Unless it changed the PH dramatically. You might want to spread some nitrogen first but I doubt that sawdust used as mulch sucks it up out of the ground. This is a combination of oak, oak ply, 5 different kinds of regular ply, birch, birch ply, maple, popular and pine. there is some folklore (that should raise a stink) about walnut or black walnut but I don't use any of that, yet.

BRuce

BRuce wrote: :> :>>have ideas about any harm from plywood sawdust? Thank you for any and all :>>replies. Larry

Plywood contains a lot of glue, and some formaldehyde, I think, so I'd call a plywood manufacturer.

: there is some folklore (that : should raise a stink) about walnut or black walnut but I don't use any : of that, yet.

Walnut shavings and dust are seriously toxic to horses:

-- Andy Barss

I avoid using any composites, such as MDF, plywood, etc... and their shavings and dust, in fireplaces, gardens, pet cages, etc...

I may be overly cautious, but it's worked for me.

Barry

From what I have read, done and heard from the Saturday gardening specialist on Saturday radio, sawdust can be very good mulch. It does take nitrogen from the soil as it decays. It was suggested to mix some high nitrogen fertilizer with the sawdust if used directly as a mulch. How much, I don't know. It is much better to compost the sawdust first. Sawdust by itself doesn't decompose very fast. There are some liquid additives that can be obtained from the local gardening center for composting dry leaves that aid in enhancing the decay process. Also, you can mix it with other compost material such as kitchen scraps. Sawdust from Walnut and treated lumber should not be used. I don't know about ply and mdf, but personally, I wouldn't use it unless it is small amounts mixed in with regular sawdust in the dust collector.

At home, I apply straight sawdust over the whole garden after the plants are up. I don't mix anything with it or compost it first (too lazy), and garden produces well every year.

Can actually be an advantage. Remember nitrogen=foliage, not fruit. Does wonders for the potatoes.

If you pile the sawdust outdoors where it can get rain, after 6 months you can use it for mulch without it taking much nitrogen. Partially composted sawdust is great for blueberry bushes. You can help the compost process by adding lawn clippings which is high in nitrogen.

I've read in multiple different places that you - can use sawdust as it is a good organic mulch - should not, as it attracts termites So I think the jury is still out on this one.

As for the dark brown mulch you buy in the store - it is cedar shards, and is naturally termite-resistant because of cedar's natural thujone content.

- DH

True enough, as wood decays it removes nitrogen. Mixing the sawdust with a goodly amount of grass clippings will help out a fair amount.

Help on the nitrogen issue mayhap, but think of all the weed seeds you'd be introducing into the mulch that's supposed to suppress weeds...

Well, unless you have one of those artificial, chemically sustained monoculture lawns with nothing but grass growing in it.

Me, I have a crop of dandelions with a few tufts of grass mixed in. :)

veggie garden and didn't even know it.

Scott

Sawdust as a mulch is fine, just don't dig/rototill in. When dug in, that's when you have trouble with the nitrogen.

Tried it. Bleah. Too bitter to eat.

I have often been leery of using plywood sawdust as compost because of the "possibility" of formaldehyde glue usage, and have never used it in compost. After extensive research, I have never seen a definite yes or no. Newer plywood supposedly does not use formaldehyde anymore, but it's still a guessing game. Without extensive research about the plywood you are using, better to be safe than sorry when using plywood sawdust. I would imagine a very small amount would be OK, but leave that judgement up to you.

Any saw dust is not really a good mulch, generally there is to much nitrogen and will burn your plants. Composting saw dust not all that great either.

This gardening web site says that sawdust _depletes_ the nitrogen in the soil as it breaks down ... ... that must be what you meant to say ? ;-)

I'd been told that, being mostly a pine, it's too acidic for most plants but rhodies and Azaleas (a type of rhododendron) get off on it, not that I'm going to try. I just dump it in the woods behind my house.