They will work, but not for as long. The difference in the amount of lignin and suberin is the key. Bark has a large amount of lignin and suberin. Most micro-organisms cannot digest lignin, and the lipid - suberin, makes it very difficult for micro-organisms to cleave the hydrocarbon chains in conifer bark. Cottonseed hulls are almost 100% cellulose, which is easily digested by micro-organisms in soil. Soil collapse would occur much sooner in a soil whose main organic component is cottonseed hulls.

Al

Thanks Al! That makes sense. Would the CSH be good for one complete growing season?

Does your soil mix work equally as well in self watering containers or is it more suited for drip irrigation?

I don't use SWC's, but there is no reason the soil shouldn't perform very well in them. I have friends that use my soil in hanging SWC's (and probably other types as well) with very good results.

Water moves in SWC's differently than in containers that are watered from the top. Water moves upward, molecule by molecule from micro-pore to micro-pore, leaving the larger macro-pores unfilled (with water). Aeration has a tendency to remain high and compaction due to watering from above is minimized. The disadvantage is that there is less gas exchange at the root zone. When you water from above, you force old air and gasses from the soil, then, as water is removed from the soil, additional air is pulled in to replace the water. I tend to like this arrangement better.

Al

I used Al's soil mix recipe last year in all of my containers including 4 self watering flower boxes and they all did beautiful for me. I even had two big bags of hardwood fines that were left from the previous year from Lowes that I used instead of pine fines. I'm sure I will be mixing again this spring, I have some plans for a couple or so more pots (which will probably turn out to be a dozen or so)

Shirl 36