I’m sure there may be others, but so far I’ve only heard three general objections to semi-hydro culture, none of which really “hold water” for me:
“It’s not natural.”
Sorry to disillusion you, but I doubt that any orchid you have (excepting maybe native cypripediums and the like in the garden) is being grown “naturally.” There are no wild plants growing in fir bark, none in coconut husk chips, and where do they occur naturally with perlite and charcoal anyway? Flower pots are certainly not natural, either. How about mounted plants? Virgin Portuguese cork oaks? Nope, no orchids on them. The trunks of tropical tree ferns? OK. You got me there, but that’s fairly limited.
“LECA growing medium is expensive.”
Actually, not at all. The purchase price for the medium is on-par with high quality bark, but as it’s totally reusable, in a short time it ends up being far cheaper than the use of “disposable,” organic-based media. The stuff just doesn’t decompose! (Less root rot risk goes along with that.)
“You have to feed the plants all the time. All that fertilizer gets expensive.”
With the exception of osmunda, orchids get essentially the same nutrition from all media – none – so you have to add it via the nutrients you apply. Plants in Semi-hydro have the same nutritional demands as those in other media, and if you’re serious about growing your orchids well, then nutrition is a serious concern.
Look at it this way: you spend a lot of money on these silly little plants, why not try to do what’s best to keep them healthy, thereby protecting your investment? You wouldn’t buy a new car and then not change the oil or have it mechanically maintained, would you? You should also take a look at the financial facts: Using the original “MSU” fertilizer or K-Lite at typical retail prices and the recommended application rate (25 ppm N) equates to less than 2¢ per gallon!
The use of additives, media pretreatments, etc. are likewise not unique to S/H culture, but again, it’s just a matter of trying to give the plant the best shot at being the best they can.
Maybe what has happened in the case of S/H is that when folks started seeing how successful it was for me and inquired about it, I described everything that I do concerning my orchid growing, including fertilization, additives, and media pretreatment at potting time. Folks accepted it as a package, rather than looking at the combination of the media and the pots as the real difference between my general orchid culture and my S/H cultural methodologies.