I'm building a new setup for a
Dendrophylax lindenii plant. I want to really improve the growth of the plant. I've read a lot about the species and its cultivation over the past several years.
I think it's really challenging to make sense of all the different advice that people write about. For example, some people say stagnant air is the key, others think that's a very weird suggestion. Why the difference?
In all the articles I've read, there is rarely enough focus on the conditions the plant experiences in the wild, particularly in a clear-thinking fashion. Typically, there are recommendations like "humidity has to be really high, above 90%, and hot! ... and then I let it get a little cooler in the winter." There's an attempt to relate to the environment, but it trails off, and it's not totally data-driven.
(Admittedly, a lot of this could be because people are growing this species in room-or-larger scale greenhouses, and the grower needs a climate that satisfies all of the plants they're growing. It seems less common to grow
D. lindenii in a small and very controlled environment.)
Instead, I think we should be going back to the basics. The biggest differences plants experience, climatically, are: winter versus summer (or other seasonality depending on locality), and day versus night. It's simple, but it's comprehensive. It's a bottom-up approach.
And, across the vast majority of orchids, we know this: getting lighting, temperature, and humidity correct gets you at least 85% of the way to a very flourishing plant. Orchids have evolved to persist on poor nutrient availability, so the basics are all the more important. Perhaps
D. lindenii is less of a peculiarity than we expect, how would we know?
With that in mind, below I've summarized the central tendencies of the climate conditions in the Fakahatchee Strand across these primary axes of variation: summer vs. winter, day vs. night. Note that I brought the summer high down a touch from the weather data, because it seemed a little too hot for any orchid, and there is probably additional cooling in the canopy.
Winter Day
Temperature: ~70 °F
Humidity: 50%
Winter Night
Temperature: ~60 °F
Humidity: 95%
Summer Day
Temperature: ~85 °F
Humidity: 50%
Summer Night
Temperature: ~70 °F
Humidity: 95%
Wind conditions are typically low wind, with a pattern of slight increase during the day and slight decrease at night, based on sea breeze dynamics.
Looking at these data, it's interesting that humidity is so high at night and relatively quite low during the day. That was a big takeaway for me. I was talking to a successful grower recently, and they said that they think one of the keys is to "water" primarily through very high humidity, because that approach doesn't let the central node, or crown, of the plant get wet enough to rot. And I think that is likely especially the case if you are letting the surface of the roots dry almost entirely every single day with low daytime humidity. Then watering overnight. This makes sense additionally if
D. lindenii uses CAM photosynthesis, waiting for night to take up water and open stomata. In summary, these data end up making sense, and the result is intuitive.
Further, the pattern is pretty simple. Day versus night humidity is consistent year-round: dry days and wet nights. Temperatures are 10-15 °F warmer during the day than at night, and during summer than during winter. It's easy to remember, and it feels intuitive. The 10-15 °F difference is especially familiar, since a lot of orchids need this exact temperature differential to promote flowering (e.g., Phragmipediums, among many others).
All in all, I think this could be really useful. In a perfect world, we could go to everyone who has ever written about how to grow
D. lindenii, and ask them how their conditions compared to what I outlined above. Perhaps some of the extensive variation in success (or lack thereof) and in odd peculiarities they insist upon might be explainable by how they did – or did not – fit the central tendencies of the conditions in the native range of the species.
In particular, there is a ton of focus on if and how to mount this species, and I bet a lot of that comes down to pairing how much local humidity the mounting media emits, especially day versus night, and how much ambient humidity there is. From the data above, we can bet a moisture-retentive mount won't work well if you're not allowing for significant drying during the day. The plant will just stay too wet.
It's totally understandable, but I think everyone has a tendency to "lose their senses" a bit when it comes to something super special, like this species. For example, Phragmipediums are finicky, but we don't jump to hyper-specific solutions for them most of the time -- except with the similarly coveted P. kovachii! I would argue that's not a coincidence. The big purple flower suddenly has us reaching for diatomite even when we have never used it before and it's really hard to find.
Maybe rather than looking for some magic trick, or some secret ingredient, we should instead just focus on getting the basics right.
And really, maybe we are not giving the orchid enough credit. Maybe with strict adherence to the above-mentioned conditions these plants would thrive for anyone.
I would absolutely love to hear from other people about this! I think it's a super interesting discussion, not only because it's about an amazing species, but because I think it touches on some generalities about how people interact with these species, and how we are able to understand them and relate to them – or not
P.S.: If I were able to meet these conditions exactly as I described, my intuition is that the plants would grow well enough, but my next biggest concern would be the fungal symbionts. Ecology, and biology in general, still has a lot to learn about microbial community dynamics, and how those communities interact with larger organisms. Yes, there has been some work done on that for
D. lindenii by the amazing team at UF (and we thank you!), but the topic as a whole is still quite nascent in ecology and biology, with a lot to be learned in the next 10-15 years. Hopefully as the topic develops, it will help to further reveal the story of the Ghost Orchid.