It depends on your objectives.

If you want compact & bushy plants - short internodes & smaller leaves/needles, grow in smaller containers & pot-up frequently. If you want to maximize biomass - use a very large container & a fast soil.

Al

Thanks for the reply Al. I wasn't sure if the yearly potting up process (and root pruning) actually helped the growing process or if it was better to plant a small seedling in a large container and let it remain undisturbed in that same container for a few years.

Sounds like the best plan is to pot up my small trees into larger containers next March/April and leave them in those same containers and gritty soil for several seasons. The only thing I'd probably have to do each season is scratch some gypsum into the gritty mix. The Turface and granite won't collapse for many years and the pine/fir bark should last for 2 or 3 seasons.

Thanks again.

Dave

I've had a terrestrial orchid in the gritty mix going on 6 or 7 years now. They hardly put out any roots, but bloom & multiply faithfully. The soil shows no signs of being near the end of its useful life, so I expect it will last until the orchids have multiplied to the point of crowding themselves out.

Al