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.
M. tovarensis #1 (sphagnum moss) 
M. tovarensis #2 (s/h volcanic rocks)
Conclusion.
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.
Sorry this is a late comment, but are you growing any orchids successfully in semi-hydro culture?
Hey Joan. I have had a lot of success with other orchids in semi-hydro culture. I have all my Phragmipediums and a Prosthechea cochleata in s/h volcanic rocks and they do great. I just don’t think it is the perfect solution for Masdevallias. But who knows… both the M. tovarensis in this experiment is setting buds right now, but the one I tried growing in s/h only has 3-4 buds while the other one has a lot more. It could be a coincident – or not… 😉
Hi –
I enjoyed reading your Masdevallia tovarensis experiment – Tell me more about your Sphagnum moss. Is this Masdevallia planted just in the moss ? or is there other additives in the media?
– Patrick
Hi Patrick! I experimented a little with different media for Masdevallia. What I think works best on the windowsill is just lightly packed pure sphagnum moss, with no additives. Easy to keep evenly moist at all times, careful not to let it get too water logged though, or allowing it to dry out completely. All the Masdevallia I grow in the cool vivarium I keep in EpiWeb substrate or mounted on EpiWeb blocks. Works great in this high moisture and humidity environment since the medium hold water, about 70% of its own weight, but does not wick water and becoming too water logged.
Hi Karma,
I grow all of my Orchids on 3 large, deep windowsills – including Masdevallia, with some being Mounted. Unfortunatley, the only Masdevallia that I have that has declined very quickly after acquiring it is my Masdevallia decumana. I’m very disappointed, but the leaves all got yellow, brown/black spots and deep pitted pockets on all the leaves. I still can’t figure out what the problem was. On my windowsill I have a humidifier, an oscillating fan, and the Temps remain int he 60’s with Humidity varying from 60% to 99%. The windowsill is actually “enclosed” if you will by a large drape, which actually does turn the windowsill into a mini ‘micro-climate’ and I am able to maintain Temps and Humidity.
We don’t have “EpiWeb” here in the USA, but we do have sphagnum moss. Problem with my mounted orchids with spaghnum is that the moss dries out very very quickly, and I have to actually water the mounted orchids daily.
Some of the Masdevallia leaves on my orchids are turning yellow, some just the tips turn yellow, others the whole leaf. Is this from to much Light??? I didn’t think Masdevallia really needed ‘Deep shade’.
Let me know your thoughts.
– Patrick
Hej Patrick! The symptoms you describe (brown/black spots and deep pitted pockets on all the leaves) sound like a fungal problem which is usually caused by problems with the air circulation, but can also possibly be bacterial. You say you have a fan, are you running it all the time? The fan should be on all the time, 24/7. The placement of the fan, or depending on how tightly packed the plants are on the windowsill, perhaps there are “dead” spots? Physan-20 is pretty effective treatment – if it is a bacterial fungal infection. It can spread easily by watering or mist, so you might need to treat all plants, not just the affected ones. Air circulation is the best prevention and cure otherwise. Yellowing leaves could be due to a number of things, too much light yes, but then you would get the whole plant changing color, not individual leaves so much. More likely due to older leaves naturally dying off or poor water quality. Many Masdevallia can be sensitive to tap water, try using rainwater or RO water. It could also be lack of some trace nutrient, or too much fertilizer… hard to tell for sure. Mounted Pleurothallids I would expect to water every day, almost regardless of what you mount them on… I water in the cool viv 3 times per day. Hope this helps…
Hey Karma,
Ya know, I am totally baffled over this. I’m getting alot of different answers from people regarding my problem – some say “TOO WARM” while others say “TOO WET”, or not enough Air – but Yes, I do run my small 8-inch oscillating fan 24/7 which is more than adequate for the size of my Windowsill that I’m growing the Masdevallia on. I monitor my Temps and Humidity 24/7 and my readings are in line with those that Masdevallia require. The one Masdevallia that has done very poorly is the Masdevallia decumana, which has lost all but one of its leaves. However, the Masdevallia floribunda’s (I have 2 of these) do not appear to be bothered with these ‘black spots’. All of the other Masdevallia I have just acquired are all Hybrids, with the exception of Masdevallia tovarensis which arrived today.
The positive is that I do not mist my plants. I never have. It causes problems and leaf spot. What is a “dead spot” ?? . . .
I have not been using Distilled water for the Masdevallia. But I do use Distilled water for all of my Phragmipediums. The Masdies are too new to fertilize, so I have not applied any fertilizer to them as yet.
What do ya think… ?
– Patrick
Well, I did tell you it could be a number of things causing your problems, and yes, it could most certainly be temperature related. Without seeing all the parameters of your setup it is hard for anyone to diagnose exactly why you have problems. You have to look at all the advice you get and see how it applies to you. For example, since M floribunda is doing well and M decumana is not, compare their natural growing conditions. Masdevallia decumana grows at elevations of 1000-2500 meters while M floribunda at 400 to 1500 meters. So, since M floribunda is found at lower altitudes it would generally be more tolerant to warmer temps. So, possibly temp could be a contributing factor. You do not say what temps you keep, I assumed you did keep at least intermediate (if not cool) temps if you try to grow M decumana… why I did not start off talking temp, but intermediate conditions does not only mean cooler temps during the day, that also means about 10 degrees or more diurnal temperature difference to keep happy plants. I have written more about this under “how I grow my orchids”. In general, hybrinds are usually more forgiving than species, so perhaps you will do better with them. By “dead spot” I meant someplace where the fan is not reaching, or is less efficient in the room/window because it may be blocked by other plants etc..
Hey Karma,
Well, unfortunately, both of the Masdevallia decumana perished. I really just did not have the proper enviornment for them, but I did so enjoy the flowers for 1-day. My warmer tolerant Hybrid Masdevallia are doing alot better, and even my Masdevallia tovarensis is in bloom and quite lovely! There is no leaf spotting, brown spot/black spot or any problems so far with any of the Hybrid Masdevallia I have acquired, so I think I shall stay clear of the ‘cool’ growers moving forward…….
Sound like a plan Patrick! Good luck with your Masdevallia!! 🙂 I can recommend one species that might do well for you, M norae (I just posted pictures of mine). It is a very temperature tolerant species in my experience.