In my area, bark and bark mixes (both fine and medium) can be found at retail nursery, hardware, and home-improvement (Home Depot, Lowes). I find perlite, charcoal, pumice, sometimes sphag at hardware store (local chain), retail nursery.
It may have been Cym Ladye who suggested to me I check out hydroponics supply stores for coconut husk chips - and I did, and found some! (I had previously bought on-line, but shipping costs as much as the product itself!)
I pot my cyms in a mix of medium and fine fir bark with added pumice, perlite, and some styrofoam peanuts. Coconut husk chips are also good for cyms (with added perlite, can also add pumice, charcoal, styro pnuts)
I have used fine bark mix or fine chc mix for Milts.
Zygos can be potted in medium bark mix, or chc.
All these types of orchids are moist growing, so need media that retains moisture while draining well. In my experience, Zygos like to dry a bit, Cyms and Milts a bit moister.
I'd advise against using Miracle Gro orchid mix - it's very fine and heavy - too much so for most orchids.
|