I make my own mix for SWC.

I use pine bark fines, peat and Turface MVP. Roughly a 3-1-1 ratio.

If the bark fines are fresh I would stick with a ratio similar to the above, but if they are partially composted then a 5-1-1 ratio should work fine too (the popular 5-1-1 "Al's mix" found on this and other forums). Dolomite lime is added at approx 1/4 cup per cubic foot of mix.

Don't claim this is the 'best' mix for SWC, it is simply what I use and enjoy working with it. It offers better aeration to the roots than a peat based mix does, breaks down more slowly and wicks efficiently.

Thanks justaguy. Question though. Are pine bark fines a regional thing? I don't believe I have every seen those at the nurseries or big box stores. We don't have native pine trees in my area closest thing to a pine tree here are Douglas Firs.

Fir bark is fine too. Generally not sold as bark fines, but soil conditioner, aged bark, possibly bark mulch though it is often larger pieces etc.