Issues with terrarium growing (Slc. & Angraecum) - Orchid Board

Bobblybook · #1 08-29-2017, 05:15 AM

Hi everyone

I have these two orchids in my 4ft terrarium and am looking for advice. Growing under two 3ft HO t5 fluorescents (which probably need replacing soon). Keep in mind the terrarium had just been misted when these photos were taken, so it is not typically this wet.

The first is some Cattleya family hybrid, I believe it's Laelia dayana x Sc Mini Purple var. coerulea. It has been growing on a cork slab and spread quite far. It has not flowered yet though, and I feel like it's definitely large enough to flower.

I do not really fertilise these terrarium plants, and they have been in there for a few years, as I'm worried about killing the moss, and also buildup of salts etc as I am not able to easily drain the terrarium. I do have some clay balls in the bottom though, underneath the plants, so I can probably fertilise a little and the runoff will not burn the roots.

The second is an Angraecum didieri. I have had this for a number of years and it basically hasn't changed. It very rarely grows a new leaf, and loses an old one, but I am convinced it's unhappy. I am aware it's a miniature and that it will probably grow slowly, and I am really quite fond of it and hesitant to accidentally kill it off.

I do know that the roots of this species need to be quite dry - I do not water any of these terrarium plants, instead they get an ultrasonic misting regularly (every hour or so) that keeps everything moist and humid but not wet. Over time, the moss has crept up the cork, and grown over the orchid and I think it may be keeping it a little too damp. Not enough to kill it, but more than I would like.

At this point, my plan is to start fertilising both orchids (either dilute orchid fertiliser or something like seaweed extract to begin with), and then de-mount the Angraecum, and instead plant it in an empty coconut husk I have been keeping for this purpose, filled with very coarse coco-husk chunks. When I first received the Angraecum, it was in a small clay pot with a similar material, not really a potting medium at all, so I think this will be a good solution to keep the roots happy and dry.

I am just wondering if anyone has any experience or expertise with either of these families of orchids, and if the photos provide any insight into what is lacking in my setup

Specifically for the Angraecum, as the Slc. seems to be adequately happy, albeit not 100%.

WhiteRabbit · #2 08-30-2017, 08:37 PM

WhiteRabbit · #3 09-01-2017, 09:13 PM

I moved this thread to the "Terrarium" forum to hopefully get some replies. Good luck!

calvin_orchidL · #4 10-10-2017, 04:50 PM

How far are these from the tubes? If they are getting good light, the next recommendation would be a weak fertilizer solution. Also, I would remove some of the moss off the mounts - they compete for nutrients with the orchid and are not conducive to growth. Good luck!

stonedragonfarms · #5 10-11-2017, 02:58 AM

Good Evening:
Your Slc. definitely looks large enough to bloom; that being said, in my experience they really need three things to bloom optimally:
1. Light; I too grow them in enclosed cases under lights (though more wardian case style than terrarium style); those that bloom best for me are about 4-6" from the lights (I grow under a combination of 6000K equivalent Acintic White/Blue mix LEDs (ie saltwater reef tank lighting) and "warm" LEDs; lights are on 16-17 hours a day. My fc readings are about 1750-1850 at the distance between foliage and lights, though my largest case also gets a bump in light from a south facing window about 2' away.
2. Fertiliser; I got sidetracked this summer with my regime, and I notice it now that plants are starting to throw spikes... I aim to fertilise once a week at full strength, usually with a fish emulsion based feed; it's a 4-1-3; additionally I use a kelp feed once a month year round. I may try an experiment this winter and try treating a plant to the regime that I use for cymbidiums (ie feeding at every watering), but they need regular feeding to bloom best.
3. Regular watering; my best growing plants are in the two cases that I use a combination of hand watering and automated misting. I water by hand to fertilise plants, but they are also automatically misted for a duration of 1 minute three times a day--in effect, they are never dry (and the roots are always in growth); over the years that I have been growing them, I've come to the conclusion that they are best cultured like Sophronitis--ie ample humidity and very steady watering. Plants should either be tremendously under-potted in moss in clay pots or mounted (tree fern or cork works best). Misting occurs 1 hour before the lights come on in the morning, once about 4pm and a third time about an hour before lights go out--Sophronitis, in much of its natural range grows relatively dry during the day, with most precipitation (very heavy fog) occurring in the very early morning and again in the evening--mimicking this has been very beneficial I feel.
You made mention about moss on your mounts and not wanting to kill it because of fertilisation...I've got moss on a couple mounts (and in several pots of cymbidiums), all of which are fertilised regularly (in the case of cymbidiums, at every watering, barring when they get rain water by default of being outside...) I'm not sure it would be an issue.
Finally, I'd second the suggestion to trim the moss away from the Angraecum; for a fast growing plant it's not a problem (ie Lepanthes relishes growing in live moss, but if the moss is happy, the Lepanthes is usually even happier...); it would be worth finding out where in Africa/Madagascar A. didieri comes from--some of the Angraecum need a pronounced rest period of (if I remember correctly) warm and dry conditions--it has something to do with the seasonal wind pattern on the east side of Africa coupled with the fact that they are in deciduous forests--ie humidity is very high, but the plants receive more sun from bare trees and there is a period of little rainfall. I believe that it's a short window of time, but some of them need the period to trigger bloom...you might shoot Brenda Ovaitt a note (she owns Botanica Orchids in Montana and is one of 2-3 hardcore Angraecum growers/breeders in the US)
Just my $.02,
Adam