For the very few plants I've put into containers, I've made a mix very loosely based on Al's gritty mix. Mostly screened medium pine bulk mulch trying to remove as many fines as I can, plus around 15-20% other stuff like crushed rock or coarse Perlite.
The "other stuff" includes 5-10% of whatever potting mix or seed starting mix I have, and I figure that includes more than enoguh peat.
I can never get rid of all the fines from a bag of mulch, and I figure that almost replaces the peat ... just not quite as "wicking" or "hydrophillic" as peat ... but the mix I wind up with always seems more than soggy enough and more than water-retentive enough.
I've been seeking a faster-draining and more-airy mix for a few years, and really haven't gotten all the way there yet.
I think I want more #2 chicken grit (1-2 mm crushed granite) or coarser grit (very fine gravel).
And I want fewer pine bark fines (spend more time screening with 1/4" & 1/2" screens, or find a 1/3" or 3/8" screen). Probably, if I could get rid of more of the "bark dust", I would be happier about adding 10-15% peat as Al suggests.
If I found coarser grit or found and splurged on the expanded rock 'Turface' product, that coarser fraction would also make me happier about bark or peat fines. But I am very cheap!
