Back in April (5 months ago) I decided to start a little experiment with Masdevallia and different growing mediums. Until then I had only cultivated my Masdevallia i sphagnum moss, but I wanted to try goring them in semi-hydro volcanic rock. I had two near identical M. tovarensis orchids so they were a logical choice for my small experiment. Warning: Sweeping generalizations and vague scientific conclusions ahead.
Here is the report on the result.
The control, Masdevallia tovarensis #1 (grown in sphagnum moss) continued to grow and produce new leaves as usual. The leaves are nice, firm and dark green. M. tovarensis #2 (grown in semi-hydro volcanic rocks) have continued to grow and produce new leaves in the same tempo as #1, but I have removed two yellow leaves during the course of this experiment. There are a few more leaves that are looking as if they will eventually turn yellow and die. The leaves also hang lower than on the control plant. The roots look pretty good however, no harm done there, but the general state of the plant is that it looks… well, sad.
Well, the experiment was not a very scientific one and too small to draw any absolute conclusions at all. There are no drastic differences in the result, but any casual observer can tell by looking at these two plants that one growing medium seems to be the better choice – namely sphagnum moss. Since the roots still looked nice I assume there might be other factors involved than just the semi-hydro culture. Perhaps the volcanic rocks were too dense and did not let enough oxygen to the roots causing the slightly “wilted look”? Or perhaps ther is something about the nutrient uptake… hmm it would be nice to get a debate going on what this result really means.
Well, as far as I am concerned… I have actually decided to discontinue the experiment. Although the semi-hydro culture did not kill the test plant, it is clear that it is in worse condition than the control after the 5 month long experiment. I have now re-potted the test plant back into moss.