You are on the right track. IMO what you said is ok. The mix will decompose fast enough anyway if it starts out uncomposted. The only thing I learned from experience, is to start with a mix that is a bit more water retentive. The 511 drains almost too well. I needed more like 521, or 421 to start or my pots dried out way too fast for blueberries. Just don't add lime to the mix. Add garden gypsum for calcium and supplement the magnesium with some kind of fertilizer.

This post was edited by edweather on Sat, Apr 26, 14 at 17:44

Hello Need2SeeGreen. Yes you have that correct. For Al's "grit mix" you should use uncomposted pine or fir bark if possible, and for the 5-1-1 slightly composted pine/fir bark is ideal. I believe the idea here is that the more composted the bark is, the more water it will hold and the more it will fill in the small air pockets within the soil.

I'm attaching a photo I've posted in a different thread. This might help show the difference between composted and fresh bark.

The top photo shows pine bark that is mostly fresh, but just starting to break down (compost) slightly. This could be used for either the grit mix (with screening) or for the 5-1-1 mix (no screening required). The center photo shows older pine bark that is well into the composting process. As you see, the bark is still visible, but much of it has turned to small particles and dust. This composted bark is what I'm using for the 5-1-1 mix, and because it already has fine particles I'm not adding any peat to my 5-1-1 mix.

Hope that helps.

TYG

Wonderful, you-all -- thanks so much!!!