First, you probably want the 5:1:1 mix instead of the gritty mix, but since that's based on an appropriate sized bark, there's a slight problem there. Since you live in the ice box called Wisconsin, you probably don't need this soil right away? The bark WILL get easier to find as spring approaches, and since JaG buys bark somewhere in WI, hopefully he (or others) will be able to help you.

If you're really thinking about the gritty mix, I'd have to say that mixing potting soil with Turface and perlite isn't going to be much different than using straight potting mix, and the resultant soil won't be anything at all like the gritty mix. I would grow in 50/50 Turface/perlite before I would use Turface/perlite/potting soil.

Al

Laary, not sure what part of WI you are in, but you can get 2.8 cu ft bags of partially composted pine bark from BFG Supply located in 19775 W. Sommers Dr. Brookfield, WI 53045 Ph: 262-797-6482

It's suitable for the 511 mix as is, would require some screening to be best for gritty mix. It's called Fafard Aged Pine Bark. Be advised this is a wholesale business and you either need an account or a credit card, they won't take cash or check.

Someone on this forum recently mentioned that John Deere Landscape stores also carry a suitable bark product, but I haven't looked into that yet.

I do want to emphasize the point Al made about not using regular potting mix in either the gritty or 511 mixes. The entire value of both mixes is the particle size of the ingredients. Commercial bagged potting mixes almost always have pretty fine particle sizes and it's this small particle size that results in the mixes holding water *between* particles instead of just internal to the particles. This is what drives the air out of the pot and results in the low O2 environment that costs plants wasted energy.