Angraecoid considerations

[Kevinator]

I'm considering ordering from Botanica Ltd for angraecoids sometime this fall but I'm a little conflicted. Most of the one's I'm looking at require high humidity (eg Aerangis luteo-alba, Angraecum urschianum) but I have an Aerangis fastuosa that is doing fine for me right now, which from what I heard requires high humidity, along with two healthy Angraecums. My humidity drops to as low as 30% when winds come in and yet they still grow regularly. I don't know if any of you have any experiences with angraecoids and humidity but if you do please share. Here are my considerations:

-aerangis luteo-alba
-aerangis distincta
-aeranthes grandiflora
-angraecum urschianum
-eurychone rothschildiana
-jumellea comorensis
-oeoniella polystachys

[Tschimm]

I only have Aerangis citrata.
Humidity outside can also drop to 30-40% here in my garden.
I mounted it on a piece of bark, wrapped with some moss and epiweb.
Got watered every day.
It's doing quite well so far.
Btw: could this little thing on the oldest leaf be a spike ? :-)

[Kevinator]

I can't really tell what it is since the picture isn't zoomed in onto it, but from this perspective it looks like a root. My fastuosa's roots look like that when they sprout but they usually do so from the base of the plant not from a leaf.

[estación seca]

I have A. sesquipedale in semi-hydroponic culture. That room is usually around 40% humidity. When it is raining I open the French door to the outside and it gets higher humidity, but that only happens a few times per summer. It is growing fine.

[Leafmite]

It just depends. I have found that with most plants, the more generations it is removed from being taken from the native environment, the more likely it is to tolerate less than ideal conditions. It also depends on how the plant you are buying is being grown in the vendor's greenhouse. If they are giving it ideal conditions, it may have a more difficult time adjusting. Genetics of an individual plant can also play a part, too.

I grow a few of the easiest Angraecoids, including Eurychone rothschildiana. That one should do fine with lower humidity. Mine came from Exotic Orchids of Maui and haven't missed a beat since coming to Ohio.

[calvin_orchidL]

I've been trying lower humidity with my angraecoids in general. I'm now targeting 70% (as opposed to 90% previously). I grow my plants mounted, and they seem to do just fine (in fact, they relish the drying out cycle) as long as appropriate watering can be kept up.

Of your choices, I would say urschianum is the most challenging. Incredibly delicate and prone to desiccation. I had one imported from Madagascar that took about 15 months to rehabilitate, and yet in three days of an automated watering system failure, it was dead.

With that said, who knows. I've seen people have remarkable success with certain species on windowsills that I struggle with in controlled settings, so who knows! Always exciting to see new people getting into angs!

[Kevinator]

I just received some info from Brenda from Botanica and she provided me with invaluable information. Turns out, quite a few of her customers grow angraecoids in low humidity conditions without many problems. I guess I'll just have to sort out which ones i'm getting then!

Originally Posted by calvin_orchidL

Of your choices, I would say urschianum is the most challenging. Incredibly delicate and prone to desiccation. I had one imported from Madagascar that took about 15 months to rehabilitate, and yet in three days of an automated watering system failure, it was dead.

I'm a little bit confused on Ang. urschianum's watering requirements. Brenda said that it should not dry out for prolonged periods of time but i'm not sure how long that is. Calvin, how did you water yours?

[calvin_orchidL]

Originally Posted by Kevinator

I just received some info from Brenda from Botanica and she provided me with invaluable information. Turns out, quite a few of her customers grow angraecoids in low humidity conditions without many problems. I guess I'll just have to sort out which ones i'm getting then!



I'm a little bit confused on Ang. urschianum's watering requirements. Brenda said that it should not dry out for prolonged periods of time but i'm not sure how long that is. Calvin, how did you water yours?

Brenda is great, isn't she. When I grew this plant, it resented drying out, and yet also seemed to despise being boggy and wet. I had it in around 90% humidity, mounted on some dense tree fern with a few sprigs of sphagnum (away from the roots) that helped keep the tree fern moist, but not wet. It seemed to enjoy itself during it's short N. American life!

Based upon my anecdotal observations, when people talk about humidity, they're really talking about controlling evaporation rate . In mounted plants, high humidity allows you to prolong that sweet medium where the mount is 'moistish', avoiding the 'just-watered' sopping wet state, as well as the bone dry state. Controlling the length of that 'moistish' zone, the periods of bone dry and sopping wet is a challenging state to get perfect. Factors affecting the ability to achieve this are obviously humidity, and mounting medium (and of course, temperature, which affects the water content of the air, metabolic rate of the plants etc. etc. etc.)

Compensating for low humidity / dry mount medium by throwing on wads of sphagnum can prolong moistness, but I suspect creates unfavourable conditions for root growth. Many angraecoids seem to dislike too much sphagnum on the mounts, and you will notice that most of Brenda's plants will be bare-mounted on cork, with small coverings of coconut husk, or tree fern. Keeping in mind that she probably grows in a greenhouse with moist buoyant air, this works well. The typical 'wrap roots in ball of sphag and tie onto mount' might work for some of the wetter growing angs (aerangis ugandensis, rhodosticta) but will not work for many of the others (punctata, spiculata, kotchyana, brachycarpa, umbonata, ang didieri etc...)

Some plants will attach roots onto anything and happily grow, regardless of whether you're a bit too wet or a bit too dry (I have dendrobiums that will just grow more roots when it's too dry, and fewer when it's adequately moist). Other species will resent you for even prolonging that bone dry/sopping wet state by a few hours (dendrophylax lindenii, anyone?) The angraecoids tend to fall on the more sensitive side of the spectrum.

I would agree with Leafmite that locally grown seedlings are more tolerant of variations. I don't believe her urschianums are grown from local seed but I'm not 100% sure. I also agree with Adam that a third dimension to all of this is the seasonal variation, which is another challenge I am still working on!

Hope that helps! Experiment and observe the plant closely. I hope it thrives and you can come back and share your cultural success with us!

[stonedragonfarms]

Shoot Brenda (the owner at Botanica) a note, she's very helpful. She spoke at our OS last fall; my take away was that many of the Angraecoids, aside from those from the Eastern lowlands require seasonally specific humidity, ie when they are in their rainy period, they require much higher levels than when they are resting. In a way many of them are like dendrobiums, where elevation and seasonal weather patterns have more bearing than simply where in the world they come from. Many orchids grow outside of their "suggested" humidity range, the question though is whether or not they flourish. Just my 2¢,
Adam

[Kevinator]

Thanks for the help! Not sure where I should grow it though. If I put it with most of my other mounts (30-55% humidity depending on season), it will dry out by the next day so that's a little risky if that's how sensitive urschianum is. If I put it with my terrarium mounts (70-90% humidity regardless of season), I'm afraid it's not going to get enough light. The aos article written by Brenda says that it requires rather bright light (my terrarium gets slightly less than phal light). I guess i will have to ask her about this. And yes, her urschianums come from her breeding program.