I would think not. Great for the compost pile! Oak and maple compost is some of the best!

Ive used aged sawdust in potting soils and had good success. Even with a lot of age it seems to have good particle structure although Iam sure it varies depending on species, time and how it was created; sanded, shaved or cut. Why not use it as substitute for peat?

In my vegetable smart pots of 511 mix this year, I substituted maybe half the peat for aged sawdust and they did great other than the blight that got my maters.

Its an incredible soil amendment. I just cleaned out the old pile that was at a nearby pallet mill. Berries love it and my arborvitae responded really well to the 2-6" mulch layer I spread out this year.

Why not use it as substitute for peat?

Because it requires huge amounts of nitrogen to break down. You said aged, not composted, so it would take it away possible food for the plant. I would never use it.
Peat is composted. This is composting 101 basics.
Why you remove sap wood from the mixes, it isn't composted.
If by aged you mean composted, yes it would be an excellent addition.

This post was edited by Drew51 on Wed, Dec 17, 14 at 0:00

Aged is a vague term perhaps. Iam not sure how old the stuff I used was but it was pretty broken down. I would guess between 7-20 years old. This is much different than sawdust or even sawdust thats a few years old.

Composted implies that nitrogen has been added? Ive read that leaf mold has been substituted for peat moss. Aged sawdust seems to have similar properties to leaf mold but with better structure and less screening..

What are some better suggestions to get ourselves off peat and to a more locally obtained and sustainable product?

OK, well that for sure is composted and is an excellent substitute, as you have observed. So yes definitely use it!
Let's go over composting a little. Fresh sawdust has proteins, When bacteria break the proteins down to amino acids and basic nutrients like NPK and micronutrients. In the process of breaking these down they need nitrogen and take it from the soil. Once composted the bacteria no longer need nitrogen to break amino acids down further. Plants themselves can absorb and break amino acids down themselves. So once composted it's a great amendment. Sawdust also contains other molecules too, like cellulose and lignin which is what wood mostly is. This requires energy (nitrogen, sugars) to break down too.
Important thing is to let stuff compost first. Non composted stuff is OK, on surface like mulch, but not in the soil. It may also be OK deep in the soil, but not in the root zone. Eventually the bacteria give the nitrogen back to the soil, although some also escapes into the air.
ANY compost can be used instead of peat which is technically a compost. Compost get's a bad rap for drainage, actually the worse draining compost is peat! Yikes!
So using others is fine. What you are doing is excellent!
If sawdust is at least a year old you can use it.
I should have asked you before going off on a tangent, sorry. You're doing nothing wrong.
You can use noncomposted material, but you should add extra nitrogen for the bacteria. Eventually it will be available to the plant.Best not to go there.

This post was edited by Drew51 on Wed, Dec 17, 14 at 1:02

Drew, what's the best way to handle fresh sawdust? I've put it in my compost pile, but not sure if that's the best way to use it. Should I compost it in it's own pile? And if I did that, would it have to heat up to be composted properly, or is it just a matter of letting it sit in a pile for a year...

There's a local carpentry shop that occasionally gives away large bags of wine barrel oak sawdust, and sometimes maple. I've used it in the past but stopped when I realized I didn't know if it was having a good or bad effect on my compost pile. I'd like to start using it again if I can figure out the right way to do it.

John

John,

Either way is fine. If you compost alone, you don't have to worry about it heating up. That kills pathogens and stuff, but I don't think we have to worry about that. Sawdust is a brown compost. And you are supposed to mix equal parts green. So if you add a green compost (which is nitrogen) it will be a nice balanced compost, and the nitrogen speeds up the breakdown process. Coffee grounds are a green compost. High in nitrogen. A mix of coffee grounds and sawdust would be an excellent product in a year!
Mixing it in a regular compost is fine too, just remember to balance with some green additive. You may be able to get free coffee grounds at the local starbucks.

The Rodale Book of Composting: Easy Methods for Every Gardener has been an excellent source of information for me. Here's what they say about sawdust.