My First Terrarium Questions

[monivik]

Finally I'm ready to do my very first terrarium. I've got three small orchids to start with. A Macodes Petola, Aspidogyne Argentea and Pleurothallis Hamosa.

I ordered these plants online, they spent 3 days in the mail which is maybe worth mentioning that it is winter here and rather cold outside. The packaging was thin sheets of paper (the kind you put around plates or glasses or stuff that would break) and the bubble wrap around that. The sheets of paper were to be honest really wet. Ok, so I was a bit worried about the plants surviving this all. So I haven't repotted them into the terrarium yet, as I want them to have some time to get acclimatized first. I've had them for 3 days now. The temperature in my house is 68F (20C).

I am a little bit worried about the Macodes Petola as it looks as the leaves are curling a little bit. To be honest I really wanted to give this plant another try as I've had one once before but killed it. I do remember the curling leaves on the first plant too, however the problem I had with that one I think was keeping the soil too wet, because the poor plant rotted.

I do understand that Macodes Petola like warmer temperatures, and the other two are cool-intermediate. Am I right? And would this be a problem putting them together?

I do have a small heating mat, as you can see on the pictures but I have two plants on there at the moment, a Phalaenopsis Hieroglyphica and a Schilleriana. I am keeping these separate from other plants as they did have mealybugs, I've been treating them, but just to be sure. They have sustained some damage as you can see.

Ok so my final question is. How long should I wait to place the new miniature orchids in the terrarium? They're sort of in there, but I don't have the lid on so it's not covered yet and I haven't repotted them into that new medium, as you can see on the pictures.

By the way maybe good to mention that I've already got the springtails for the terrarium.

[monivik]

More pictures.

[Orchidtinkerer]

i don't think you will need a lid. You are using moss. Moss in an enclosed space is tricky. Have you got a humidity sensor - I know it's a small space but you cannot get away without one in a terrarium no matter what size.

[harpspiel]

I actually disagree about the humidity sensor, hygrometers are notoriously fickle, they get water in the probe and start reading the wrong number or read 99% all the time...I have a specific thermo/hygrometer that I do recommend (you drill holes for the probes and the body sits outside the tank) but I ignore the hygrometer readings anyway.

Instead, I rely on visuals to determine humidity level. If the plant’s leaves are curling it might be too dry. If there is condensation on the glass it’s probably too wet and needs to be aired out. If you are using a lid, air the terrarium out for at least a few hours every week. Depending on your ambient humidity levels you may not need a lid, but here in Albuquerque I would definitely use one.

The Macodes looks ok for now, and 68 is fine for it, I don’t believe it needs to be grown warm. Mine is perfectly happy and getting really big with a max of 88 in summer and a min of 60 in winter.

What’s the substrate in your terrarium? It looks really finely ground, and like it might retain too much moisture. I don’t think you can put the Pleurothallis, which is an epiphyte, into that. I also don’t see a drainage layer, and without one the soil/substrate will stay very saturated. Also, without a drainage layer minerals will build up in the soil very fast, so I recommend using distilled water at least occasionally.

I recommend watering the plants and then leaving the terrarium top off for a little while until all water has evaporated from the leaves, then putting the top on until the next time you water. This will help prevent rot. Right now I have a Racinea crispa (very fussy bromeliad) with scale quarantined in one of those latching flour jars, and I spray it to saturate it every other day and then leave the jar open for a few hours, then close the jar and leave it for another few days. If there’s a lot of condensation and things are rotting, try growing without the lid altogether.

[monivik]

Originally Posted by harpspiel

I actually disagree about the humidity sensor, hygrometers are notoriously fickle, they get water in the probe and start reading the wrong number or read 99% all the time...I have a specific thermo/hygrometer that I do recommend (you drill holes for the probes and the body sits outside the tank) but I ignore the hygrometer readings anyway.

Instead, I rely on visuals to determine humidity level. If the plant’s leaves are curling it might be too dry. If there is condensation on the glass it’s probably too wet and needs to be aired out. If you are using a lid, air the terrarium out for at least a few hours every week. Depending on your ambient humidity levels you may not need a lid, but here in Albuquerque I would definitely use one.

The Macodes looks ok for now, and 68 is fine for it, I don’t believe it needs to be grown warm. Mine is perfectly happy and getting really big with a max of 88 in summer and a min of 60 in winter.

What’s the substrate in your terrarium? It looks really finely ground, and like it might retain too much moisture. I don’t think you can put the Pleurothallis, which is an epiphyte, into that. I also don’t see a drainage layer, and without one the soil/substrate will stay very saturated. Also, without a drainage layer minerals will build up in the soil very fast, so I recommend using distilled water at least occasionally.

I recommend watering the plants and then leaving the terrarium top off for a little while until all water has evaporated from the leaves, then putting the top on until the next time you water. This will help prevent rot. Right now I have a Racinea crispa (very fussy bromeliad) with scale quarantined in one of those latching flour jars, and I spray it to saturate it every other day and then leave the jar open for a few hours, then close the jar and leave it for another few days. If there’s a lot of condensation and things are rotting, try growing without the lid altogether.

Thanks. Well, let me attach another picture. It does have a bottom with pebbles, then a the thing I cut out as a mat with holes in it (I don't know what you call that), it's got the charcoal.

Yeah and the potting mix I made after the "recipe" from Serpadesign (Youtube) that he uses for the tropical plant terrarium. So it is one part coco-peat, one part small bark, less than one part sand (this is special one for plants) and then two parts of spaghnum moss. Do you think this is too "moisture retaining"? Should I add more bark to it? I could add perlite, I've got some of that laying around too.

Yeah, I got the feeling it looked a bit too wet at first that's why I haven't placed the plants into the mixture yet, they're still in their pots. Also I haven't indeed put the lid on so far.

I don't have any small thing to measure humidity with, I do have a big thing standing on a table with indoor/outdoor temperature plus indoor/outdoor humidity. The humidity indoor is 60 percent.

Ok, so in regards to the Pleurothallis. Any suggestions on how I place it inside the terrarium? On top of a heap of bark? It the pot that it's now, it looks it's been planted in just spaghnum moss.

[Orchidtinkerer]

Originally Posted by harpspiel

I actually disagree about the humidity sensor, hygrometers are notoriously fickle, they get water in the probe and start reading the wrong number or read 99% all the time...I have a specific thermo/hygrometer that I do recommend (you drill holes for the probes and the body sits outside the tank) but I ignore the hygrometer readings anyway.

Instead, I rely on visuals to determine humidity level. If the plant’s leaves are curling it might be too dry. If there is condensation on the glass it’s probably too wet and needs to be aired out. If you are using a lid, air the terrarium out for at least a few hours every week. Depending on your ambient humidity levels you may not need a lid, but here in Albuquerque I would definitely use one.

that is like saying you bought a dodgy burger once and so won't eat burgers anymore. Or your car broke down so all cars are going to break down.
Your observations to a point are accurate as in there are some low quality sensors on the market. Expensive sensors are expensive but water condensation tells me nothing as that happens on a cold window, the humidity could be completely different half a meter away as I have discovered with sensors which without I would be none the wiser I need fans in certain areas to move humidity traps.
Even if you get a half way reliable sensor I have found they lose reliability in the higher humidity ranges. I have a couple of good monitors but some I know will not display accurately above 70% anymore. I discovered this "visually" like you say by noticing an orchid had developed crown rot. I checked with sensors (more reliable ones) and humidity had been at 90% when my sensor was showing 70%! But that is because I did not invest in a better sensor. There are reliable cheap ones but it can be hit and miss and that is a problem but one should not say ok well if the manufacturers can't make good ones then I will stop using a tennis racket to play tennis for example (bare handed tennis) or if my lawn mower is rubbish I won't decide to get a sheep instead, I will get a better lawnmower.

Even if sensors are not 100% reliable - they are still a very effective way of monitoring the situation, I would rather do that than rely on my orchids going downhill to tell me something needs changing.
Maybe I was too confident in relying on sensors, they do make things easier than having to constantly check on things. It is surprising how much a cold night or a hot day can affect humidity and change things day to day.

[harpspiel]

I think an expensive hygrometer is overkill for a jar terrarium. Do a search for “hygrometer” on Dendroboard (they’re really the high-tech orchid enclosure experts over there) and you’ll see I’m not the only one who has found them to be fickle and generally not worth it in an enclosure that gets misted regularly. And I haven’t experienced crown rot in an orchid just from high humidity, I thought it was usually caused by water sitting in the crown, which is something you can assess visually rather than with a sensor.

---------- Post added at 09:00 PM ---------- Previous post was at 08:33 PM ----------

Originally Posted by monivik

Thanks. Well, let me attach another picture. It does have a bottom with pebbles, then a the thing I cut out as a mat with holes in it (I don't know what you call that), it's got the charcoal.

Yeah and the potting mix I made after the "recipe" from Serpadesign (Youtube) that he uses for the tropical plant terrarium. So it is one part coco-peat, one part small bark, less than one part sand (this is special one for plants) and then two parts of spaghnum moss. Do you think this is too "moisture retaining"? Should I add more bark to it? I could add perlite, I've got some of that laying around too.

Yeah, I got the feeling it looked a bit too wet at first that's why I haven't placed the plants into the mixture yet, they're still in their pots. Also I haven't indeed put the lid on so far.

I don't have any small thing to measure humidity with, I do have a big thing standing on a table with indoor/outdoor temperature plus indoor/outdoor humidity. The humidity indoor is 60 percent.

Ok, so in regards to the Pleurothallis. Any suggestions on how I place it inside the terrarium? On top of a heap of bark? It the pot that it's now, it looks it's been planted in just spaghnum moss.

As far as the mix, that sounds ok, it might retain too much water but really only time will tell. I didn’t notice the drainage layer before but that looks good too, you might want it a little deeper so you have more wiggle room for it to hold excess water - 1 1/2” to 2” is the usual standard. Up to you.

Personally I don’t like Sphagnum as a potting medium, I find it holds onto too much water, so I would use a regular orchid bark mix. But you could leave it in a pot in the Sphagnum for now and just check the roots for rot regularly. To be clear, I do like Sphagnum, particularly live Sphagnum, as a water retention pad around the roots of mounted orchids, just don’t like it in pots.

[monivik]

[/COLOR] As far as the mix, that sounds ok, it might retain too much water but really only time will tell. I didn’t notice the drainage layer before but that looks good too, you might want it a little deeper so you have more wiggle room for it to hold excess water - 1 1/2” to 2” is the usual standard. Up to you.

Personally I don’t like Sphagnum as a potting medium, I find it holds onto too much water, so I would use a regular orchid bark mix. But you could leave it in a pot in the Sphagnum for now and just check the roots for rot regularly. To be clear, I do like Sphagnum, particularly live Sphagnum, as a water retention pad around the roots of mounted orchids, just don’t like it in pots.[/QUOTE]

Me too. Spanghnum moss is not my favorite potting medium. But not because there's anything wrong with it. But because I am not good with it.
Every time so far that I've had anything potted in spaghnum moss I kill it. Seriously! That's how my first Macodes Petola died. I tend to overwater I suppose because I don't know how to water a plant potted in spaghnum.

I might then just make the mix a bit chunkier.

But now something else: I've spotted a fungus gnat in the terrarium!!! NOOOO!!!! I hate the stupid fungus gnats.

I know I've been having a problem with them. I've been fighting them off for months now. I've repotted almost every plant. I'm using Mosquito Dunks. I've even got these decorative pearls on top of the soil of my regular plants, so that you can't see the top soil. I think the Calatheas have been the problem, but I bought a moisture meter that I've been using to determine when to water. I don't think the other orchids are the problem, they're in chunky bark.