Can Caularthron bicornutum grow in SH?
 

Hello everyone! I went and made a few more impulse buys again. Sigh! I never learn :) anyway, long story short I am the proud new owner of not one but two Caularthron bicornutum, whatever they are. Never heard of this plant but it looked interesting. So now I am thinking of repotting them and was planning to put one in bark and charcoal (that’s what both came in) and one in SH with lecca. I’ve looked up this plant in the SH list on the sticky but nobody mentioned it. Would it work you think? I’d like to see the comparison on how they do but I don’t want to kill either :)

I have always thought the “S/H List” kept here was a waste of time at best, and misleading at worst.

The question “will (this plant) grow in S/H” cannot be answered, because ANY plant can be grown in semi-hydroponics, but that does not mean that any grower can do so.

While “semi-hydroponics” only defines the water delivery and the use of an inert medium, folks seem to think that is fully defines all aspects of orchid culture.

What determines whether an individual can grow a particular plant in S/H culture is how well ALL of the other cultural parameters he or she can provide work with reservoir and LECA to provide what the plant needs.

You might also consider that those parameter will be different from grower to grower, they can also change seasonally, as well.

For example, in my warm greenhouse in Pennsylvania, phals thrived in S/H. When I moved them to North Carolina, they did even better out on a hot, humid deck in the summer. However, when they came in for the winter, the evaporative cooling in the cooler, drier indoor air led to the roots being too cold, so I have had to move them to a different growing technique that can provide better in-pot conditions for them.

Now that I’ve gone on about that, the short answer to your question is “yes, caularthrons can be grown that way, if your conditions favor it”. I’ve seen many do so.

I’ll add that sometimes, the evaporative cooling can work FOR you, as well. I have a friend who has struggled with Phrag besseae because his apartment growing conditions are just too warm for a plant that naturally grows at 2500m elevation and never sees temps above 20C. He moved it into S/H culture, where the evaporative cooling lowers the medium temperature and the constant water supply is more like they get in nature, and “boom”, now they’re fine.

I haven't looked at that list for years, other than when I first started lurking here. You're correct, Bill, it's not helpful at this time, and also misleading. I unstuck it.

Maru777, what Ray says is right on point. If you grow other things successfully in semi-hydro and have your culture down, sure it will grow. If you've never grown that particular genus, and sounds like you haven't, you might want to research its culture prior to experimenting so you know its requirements. No one wants to lose an orchid, but an "experiment" always has risk.

Thank you, both! I am the type that reads instructions, so I have been looking up its cultural needs. It seems to like warm weather so that should not be an issue for me since it’s warm year round. I was curious about just how much of a drop in temp would evaporative cooling would be able to achieve. So far I have found a range of 1-2 C which for my usual temps is nothing. In your experience is that about right? I have a few orchids I am seriously longing for but I have stayed away from because they need cooler weather.

I was a bit concerned because both the AOS and a few other sources I found said it needed to dry out in between waterings. I used some pretty large lecca pebbles so hopefully that will give it enough air around the roots and I hope that is what their instructions are getting at. I have some Phals, some dendrobiums and a few cattleyas in SH so far and they seem to be happy so hopefully this one will not die for science :) Wish me luck :) I’ll give it a try.

I personally don't see a significant enough drop in temperature with SH to worry about it one way or another, and don't factor it in overall regardless of the genus. I can tell you that a cool grower (like Maxillaria) won't survive a summer in Kansas regardless of being in SH or not. If I want to grow it, it has to be set up in air conditioning for at least four or five months out of the year (so I quit growing them). Yours is an intermediate to warm grower, so I wouldn't give it a second thought.

There are a LOT of orchids that many say must dry out some before watering again. My opinion is with semi-hydro it doesn't matter. The roots adapt to the method, and it becomes irrelevant for the most part. I grow everything in SH, other than a few mounted, and have for more than a decade. Many, maybe even most of them, are supposed to dry out before watering again. The only thing I've lost in SH involved different cultural issues that I wasn't meeting for the plant.

No orchid “must” dry out between waterings. Letting the potting medium dry out is a way to compensate for crappy potting media that holds a lot of water in the spaces between particles.

Don’t be too concerned about LECA size. It’s going to be “airier” that most other media, material what.

:rofl: True! It did say the same for the other ones I have in SH, you are right and they do just fine.

Thank you for the guidance! One is in SH and one in bark with charcoal. We shall see how they do as a side by side comparison. My own tiny experiment. I have another similar one with two renantheras but I messed that one up because I changed one more variable by moving one to a different spot in the house :)