# Why is armeniacum such a huge pain?



## kentuckiense (Feb 15, 2009)

Well, it is for me, anyway.

My armeniacum has slowly been shedding leaves. It is now down to two leaves and I have come to accept the fact that it is going to die. Is there a trick to these things? I grow almost all the other Parvisepalums and, if I do say so myself, I think they like (or tolerate) my conditions. I have no trouble with micranthum (including var. eburneum), malipoense, emersonii, delenatii, and I've even bloomed my vietnamense as well as numerous parvi primaries. I even have trouble with some armeniacum hybrids! I've killed an Armeni White (who does that?!), and my Wössner Vietnam Gold and Fumi's Delight have also been doing the leaf-shedding thing, albeit a bit more slowly than the species.

From looking at the extremely narrow geographic range of armeniacum, I would have to guess that they have fairly narrow ecological requirements and thus the problems with cultivation.

Growing in a standard bark mix about 8 inches under T8 shoplights. Relative humidity is somewhat low, but not bone dry, and I mist all my plants at least 4 times daily. Once summer rolls around, I'm considering picking up a larger plant and trying the basket technique. Any other advice?


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## NYEric (Feb 15, 2009)

Move it further from the light and give more water.


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## John M (Feb 15, 2009)

kentuckiense said:


> Is there a trick to these things?*Yes.*
> Growing in a standard bark mix about 8 inches under T8 shoplights. *Repot in 50% limestone gravel and 50% your bark mix. Use GroLux Wide Spectrum bulbs mixed with your cool white bulbs. One GLWS to one, two or three cool white is good.*Relative humidity is somewhat low, but not bone dry, and I mist all my plants at least 4 times daily. *Misting is a temporary solution to a permanent problem. You get to feel that you are doing something to help; but, if your humidity is low, you're not really helping at all. In dry conditions, after you mist, the air is humid for maybe 10 minutes. Better to place the plant inside an open topped, wide mouth glass jar or small aquarium. You want the top completely open to prevent any heat build up and too much humidity; but, the glass sides and bottom will create and hold a microclimate of humidity around the plant. Keep a tiny bit of water in the bottom with the pot above that. After you repot, water thoroughly and then feed with a transplant fert a couple times, a week apart @ 1/4 strength.
> I use 10-52-10. Good luck! *QUOTE]


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## SlipperKing (Feb 16, 2009)

I really think John is onto something here when he suggest a 50/50% mix.
I lost every armeniacum I ever had in a bark/sponage rock/charcoal mix. Now my plants are doing a 180 degree flip with the same mix in a basket plus I added crushed oyster shell in the mix and as a top dressing. I grow in a GH so I can't give advice for lighting or the humidy aspect of it. The plants definitely like a drier period time in the root zone. That probably why they put out such long stolens.


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## dan_t (Feb 16, 2009)

All the armeniacums I've got are in fine bark/perlite mix in a basket, but the bottom third of the basket is taken up by limestone chippings. I started to do this having read Cribb's paper on its habitat, and it seems to be doing great, so far... I give it plenty of water in the summer, dry and cool in the winter, much like some Dendrobs.

Dan


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## SlipperKing (Feb 16, 2009)

Good points Dan on seasonal changes of water and temp


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## Rick (Feb 16, 2009)

Both John and Dan have good points.

I have always used limestone gravel in the bottom of my parvi pots (except delenatii), and I supplement the mix with oyster shell too. And in the last year I've started using allot of bone meal as a top dressing.

I beleive it was Sanderianum that had some field observations of soil pH around armenicums, and said that the pH was generally above 7 in the younger active growth areas and low around old bloomed out growths that were dying back. Bark mixes start out at pH's less than neutral, and drop to as low as 4 in a fairly short time.

There are several implications to low pH, one of which is the availability of phosphorus drops dramatically below the low 6's, and without p available your plants may be eating themselves up for it even if you are adding it with a fertilzer mix. You'll notice that John's fertilizer choice is a high P bloom booster type. Also limestone rock has a fair amount of P in it, and oyster shell is a P sponge that the plants can access long term.

The humidity bit that John mentioned I think is also very important, and before I started regulating air humidity 24/7, I also saw allot of leaf drop in my paphs in general. The parvis aren't nearly as picky as the barbata, but I say that armenicum would still appreciate a pretty constant 60%.


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## GaryB (Feb 16, 2009)

I think you will get improvement with higher humidity and higher light. In their natural environment, humidity in 80% in the summer and 60% in the winter. Armeniacum do well with 1800 - 2500 fc. Also, cooler night temperatures in the winter (50s) help set buds.


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## Corbin (Feb 16, 2009)

Rick said:


> I beleive it was Sanderianum that had some field observations of soil pH around armenicums, and said that the pH was generally above 7 in the younger active growth areas and low around old bloomed out growths that were dying back. Bark mixes start out at pH's less than neutral, and drop to as low as 4 in a fairly short time.
> 
> There are several implications to low pH, one of which is the availability of phosphorus drops dramatically below the low 6's, and without p available your plants may be eating themselves up for it even if you are adding it with a fertilzer mix. You'll notice that John's fertilizer choice is a high P bloom booster type. Also limestone rock has a fair amount of P in it, and oyster shell is a P sponge that the plants can access long term.




How do you measure the pH of the bark mix?


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## Rick (Feb 16, 2009)

Corbin said:


> How do you measure the pH of the bark mix?



You could try soaking the pot in DI water for a half hour and see what the pH of the residual water ends up. There are also soil pH meters, but I'm not sure how effective they are in mixes that are real open (like a bark mix). Most of the soil probes I've seen like good contact between the soil and the probe.

This is a good question Ed. There was an article in Orchid magazine a few years back that tracked mix pH, and it might be good to see if we can pull a protocol out of that. My old man memory seems to recal a pore water approach.


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## Corbin (Feb 16, 2009)

Come to think of it, I have an article, maybe the same one you are thinking about, at the apartment that discuss this. I'll look it up and report back.


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## jblanford (Feb 18, 2009)

Where does one find limestone gravel?. Jim.


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## NYEric (Feb 18, 2009)

Yeah I was wondering the same thing, there seems to be a problem in NYC getting some of the materials listed here!


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## SlipperKing (Feb 18, 2009)

NYEric said:


> Yeah I was wondering the same thing, there seems to be a problem in NYC getting some of the materials listed here!


Eric, aren't you in the transportation business? Surely you have a friend or two that can get you a dump truck load


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## NYEric (Feb 18, 2009)

I can get quarry material all the time; but how do I know what it is?


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## SlipperKing (Feb 18, 2009)

Google and read the lingo...something about soft vs hard granite like


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## NYEric (Feb 18, 2009)

When's the last time anybody got hit in the head w/ a 'soft' stone!?


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## Jim Toomey (Feb 18, 2009)

Marine fish pet stores sell limestone gravel for salt water tanks.
Just rinse real well!
AHAB


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## Rick (Feb 18, 2009)

Much of the SE is on Karst limestone. If it wasn't so heavy I could send you tons of limestone sand and gravel from a local quarry for cheap.

Maybe I need to start a new business.:wink:

Use of oyster shell is a really good start though:wink::wink:


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## Eric Muehlbauer (Feb 18, 2009)

How about marble chips? I've seen them sold as a topping for potted plants...they are usually about 1-2 cm in diameter. Or the crushed coral sold in pet shops?


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## John M (Feb 18, 2009)

Eric Muehlbauer said:


> How about marble chips? I've seen them sold as a topping for potted plants...they are usually about 1-2 cm in diameter. Or the crushed coral sold in pet shops?



No; marble chips are no good. Crushed coral would probably be good; but, I don't know for sure and it'll be WAY more expensive than simple crushed limestone gravel. Building supply places that sell cement usually also sell crushed limestone.


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## Eric Muehlbauer (Feb 19, 2009)

Why wouldn't marble be good? isn't it just metamorphic limestone? How about dolomite gravel? Its also sometimes sold in petshops....


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## TyroneGenade (Feb 19, 2009)

jblanford said:


> Where does one find limestone gravel?. Jim.



Pet stores will also sell coral chips or shell grit. Theses, being organic in nature, will provide a far more usable source of phophate, calcium and magnesium. These substance are also lighter than lime stone or dolomite.

If you eats lots of eggs you can use egg shells as well.

Regarding the humid environment. Get a 2 L (~half gallon) coca-cola bottle and cut the top off. Punch holes in the side about 1/4 inch from the bottom. The plant pot should be able to rest in the bottom of the bottle well above any water that accumulates in the bottom corners. The plant may be a little cramped but you can rest assured that all excess water will drain from the plant unhindered and it will never stand in the water with its feet wet. You don't need to use a coke bottle... Any large plastic container which you can punch holes into below a preconstructed stage would work.

This has been a very interesting thread. If I can find an armeniacum locally (and afford it) I will now know exactly what to do. 

Thanks


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## kentuckiense (Feb 19, 2009)

Eric Muehlbauer said:


> Why wouldn't marble be good? isn't it just metamorphic limestone? How about dolomite gravel? Its also sometimes sold in petshops....



Yeah, I'm curious too. I know this is purely anecdotal, but the best Parvi grower I personally know puts a considerable amount of marble chips in his mix.


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## Corbin (Feb 19, 2009)

For those of you who are interested, instructions for using the pour through method to check the EC and pH of your mix can be found in at in the January 2005 issue. www.atlantaorchidsociety.org/newsletters/2005_01AtOSNewsletterWeb.pdf

The article starts on page 8 and the instructions for the pour through test are on page 9.


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## John M (Feb 19, 2009)

Eric Muehlbauer said:


> Why wouldn't marble be good? isn't it just metamorphic limestone? How about dolomite gravel? Its also sometimes sold in petshops....


 I might be getting ahead of myself here. I don't have a scientific answer for you. However, marble seems to me to be more inert; having a more "glass-like", non-porous quality. Crushed limestone gravel is more "rough" textured, absorbs water and it will slowly over time, disolve into solution; providing a pH buffering aspect as well as calcium. I have no idea about whether or not dolomite gravel would be good or not. My feeling is that since the plants are growing on limestone outcroppings in nature, why not just use limestone in the potting mix, instead of a substitute? It's cheap and readily available (except apparently, in NY city). Using something else that may make calcium more "available" doesn't necessarily mean that it's better. You could end up with a calcium toxicity problem. I believe in K.I.S.S. If limestone works in nature and it's cheap and easily available, then, why risk mucking things up by experimenting with other additives.


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## Rick (Feb 19, 2009)

John M said:


> I might be getting ahead of myself here. I don't have a scientific answer for you. However, marble seems to me to be more inert; having a more "glass-like", none pourous quality. Crushed limestone gravel is more "rough" textured, absorbs water and it will slowly over time, disolve into solution; providing a pH buffering aspect as well as calcium. I have no idea about whether or not dolomite gravel would be good or not. My feeling is that since the plants are growing on limestone outcroppings in nature, why not just use limestone in the potting mix, instead of a substitute? It's cheap and readily available (except apparently, in NY city). Using something else that may make calcium more "available" doesn't necessarily mean that it's better. You could end up with a calcium toxicity problem. I believe in K.I.S.S. If calcium works in nature and it's cheap and easily available, then, why risk mucking things up by experimenting with other additives.



You are basically correct John. Limestone (including dololitic limestone, which has a bit higher ratio of magnesium in it compared to other limestones) is softer and more disolvable than marble. Under acidic conditions it will actually dissolve pretty fast. It also has some ion exchange or absorption capabilities that can hapen quickly. Marbles are chemically much more inert.


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## Rick (Feb 19, 2009)

Corbin said:


> For those of you who are interested, instructions for using the pour through method to check the EC and pH of your mix can be found in at in the January 2005 issue. www.atlantaorchidsociety.org/newsletters/2005_01AtOSNewsletterWeb.pdf
> 
> The article starts on page 8 and the instructions for the pour through test are on page 9.



Thanks Ed. David Mellard is an AOS judge too. He's actually in a similar buisiness to what I do, and have discussed some of the implications of water/substrate chem and orchids.

There is also an old AOS article, but I haven't looked for it yet. I also suspect that most of the field data for soil pH was conducted with a direct soil measuring device, and not with a pour through method. The direct measuring probes seem OK for fairly dense humid soils, but I have had very inconsistent results in orchid potting mixes. The main thing will be to pick a method and be consistent from soil to soil.


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## cnycharles (Feb 19, 2009)

the slowly fading bottom leaves is a sign of the plant using up stored energy or nutrients either because of not enough rest period or not enough fertilizer. I also had that problem and my humidity was very low. I've put my two armeniacums in homemade baskets with limestone chunks in the bottom, chopped leaf litter in the middle and tree moss growing on fallen logs out in the woods on top. seem to be happier

one article I read here talked about how someone in california I think had very good luck and they talked about doing the same thing as above (except using live sphagnum instead of sheet tree moss) and they used some sort of leftover ground up and pressed beans used in oil production as a sort of long-term slow release fertilizer. I just found something very similar from japan in an internet bonsai store. haven't purchased any yet

also I'm sure crushed coral can be found in most pet stores, and the stuff from florida is from fresh water areas so it doesn't have salts (at least that's what the bag says. granite is pretty insoluble but probably good for making an airy mix and maybe keeping the media/roots cooler at times


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## biothanasis (Feb 19, 2009)

TY all for the very interesting info!!!


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## Rick (Feb 20, 2009)

Rick said:


> Thanks Ed. David Mellard is an AOS judge too. He's actually in a similar buisiness to what I do, and have discussed some of the implications of water/substrate chem and orchids.
> 
> There is also an old AOS article, but I haven't looked for it yet. I also suspect that most of the field data for soil pH was conducted with a direct soil measuring device, and not with a pour through method. The direct measuring probes seem OK for fairly dense humid soils, but I have had very inconsistent results in orchid potting mixes. The main thing will be to pick a method and be consistent from soil to soil.



The article on pH and fertilizer rates for paphs is in the November 2005 issue of Orchids. A big flaw of the study (which is why we are wondering specifically about armeniacums) is that the author assumed that all paphs require the same pH and Ca requirements. His study plant was a Maudea/barbata hybrid, and not a calciferous species. The chemistry aspects of the article are pretty good otherwise. He used a pour through method for determining pH, but the protocol is not detailed in the article. I have also located an EPA protocol for soil pH determination, but it involves complete immersion of a soil sample for about 3 hours.


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## Eric Muehlbauer (Feb 20, 2009)

I picked up 2 lbs of crushed coral today, from a pet store...cheap enough, $2/lb....now, can I use this as is, or do I have to soak it for days to leach out salts? The store owner said that I didn't have to, but I figured I'd check for other opinions first.....Take care, Eric


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## cnycharles (Feb 22, 2009)

Eric Muehlbauer said:


> I picked up 2 lbs of crushed coral today, from a pet store...cheap enough, $2/lb....now, can I use this as is, or do I have to soak it for days to leach out salts? The store owner said that I didn't have to, but I figured I'd check for other opinions first.....Take care, Eric



the plants I've used the crushed coral on haven't looked bad at all, actually much better than plants that I had put into large coconut husk chips (which are likely to have salts still in the center of the chip from what I've gathered). that said, I don't think it would hurt anything to rinse them or anything else. ...especially if you're going to use it with some special or expensive plants then why take a chance? i'm pretty sure, though that the spots where the crushed coral is taken from are fresh water soaked areas (at least in florida) that have water moving through them, so maybe not likely to have that much salt in it


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## SlipperKing (Feb 23, 2009)

Give your opinion on this idea:
I've been using a mixture of CHC and bark ~50/50 plus sponge rock and charcoal. things were fine at first but about the time fall came a round the plants look unhappy ( can't discribe it other then unhappy) so I started in with the crushed oyster shell and a dab of bone meal here and there. The plants really look much better, growth-wise and blooming. I think the CHC and/ or the bark start to become very acid and by adding the above mentioned items I've "neutralized the mix" and the plants are responding to it. .,......Any thoughts? I really don't think salts have anything to do with it from the CHC.


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## Eric Muehlbauer (Feb 23, 2009)

Well, I repotted 2 armeniacums in bark with my crushed coral...didn't rinse it, it was pretty clean. I assume other parvis should be treated the same way? Brachy's too? As for CHC, I've given up on it for paphs. Only my strap leafed paphs remain in it (they tolerate it well, and don't lose roots...). I would think that if the mix is getting acidic, its the bark that's causing it. But I have found that with paphs, CHC does not last any longer than bark. And the results of deteriorating CHC are worse than deteriorating bark, which can be relieved by extra sponge rock, etc in the mix. The only roots the grow in CHC after a few months are at the top..few or none at the bottom. I don't think salt is an issue...I would soak it at least 3 times, with 5 gal water to 1 gal or less CHC, the 2nd soaking with CaNO3 and MgSO4....If salt were an issue, damage would occur quickly. Instead, paphs in CHC respond very well, then go downhill after a few months. Take care, Eric


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## orchidmaven (Feb 23, 2009)

Many years ago, I had a visitor from China in my greenhouse. I bemoaned the fact that my nice plant of Paph. armeniacum was to say the least, not performing. It was growing with my complex and seedling paphs in the intermediate house. He suggested I move it in with the Masdevallias and Odontoglossums we were growing at that time. It has done well ever since. Many Paphiopedilums can be grown in all kinds of potting mix. It is like alchemy, searching for the gold formula. I do not subscribe to the potting mix of the month club.

Theresa,
Hillsview.


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## Leo Schordje (Feb 24, 2009)

I agree with Theresa, in my experience Paph armeniacum really appreciates it a touch cooler than most Paphs. Both summer and winter, though I do run mine warmer in summer than winter. I also agree with the comment about potting mix of the month. A BIG DANGER in adding stone to organic mixes is that what was a light & airy mix will suddenly become heavy and dense. If the majority of your plants are in a light mix, you will always be out of sinc for when the heavy stone laden mix will need water. K.I.S.S. I use a simple fir bark & charcol mix, for the parvi's I top dress with crushed oyster shell & or a small amount of pelletized horticultural lime. This way watering frequency doesn't differ radically from my other orchids. Caution with the pelletized lime - too much is a bad thing, it is more soluble than stone chips, you can burn a new transplant. Crushed oyster shell seems inert enough that you can be sloppy about the quantity used, I have never had a burning problem with crushed oyster shell. I get my oyster shell from the Saddle & Feed Store, or Farm & Fleet, it is sold for poultry grit, about $4 for a 25 pound bag. 

But if you do want to add crushed limestone, or use limestone chips in the bottom of the pot, in the Chicago area most of the Wall Marts, Menards, etc sell small bags of 'crushed marble', which is quarried locally. It is not true marble, but really a Silurian Limestone, not quite metamorphosed enough to be real marble, but it is a brighter white than other local limestones. Most of what is sold as marble chips is really a limestone that is only partially metamorphosed. I have used it as it is convenient and cheap enough. I have used limestone chips in the bottoms of pots of some brachys, parvis and big roths and sanderianums. A little is okay, too much and it changes how frequently your pot will need watering. I have too many plants to water each on its own schedule, so keep this in mind when you fool around with different mixes. Each mix variation will change how often you need to water. 

Hope this helps
Leo


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## NYEric (Feb 25, 2009)

I will look to see what NJ Home Depots have. THe crushed oyster thing is like imposible to find in NYC!


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## Corbin (Feb 25, 2009)

I have a question about the top dressing with crushed oryster shell. How much do you add (by weight or by volume). Lets assume a 4" pot.


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## Eric Muehlbauer (Feb 25, 2009)

You can get small packages of crushed oyster shell in Petland. Eric- isn't there one near you on 6th Ave?


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## NYEric (Feb 26, 2009)

It's not crushed oyster it's mixed w/ other stuff!


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## Eric Muehlbauer (Feb 26, 2009)

I know the mixed stuff...its sold as "bird grit"...but at my local Petland I can buy pure crushed oyster shell in pouches...not as good as the stuff they used to sell, in small cardboard containers..this stuff is a little too finely crushed, but its still oyster shell.


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## Leo Schordje (Feb 27, 2009)

I use about 1/4 teaspoon per inch of pot size for top dressing with crushed oystershell. A four inch diameter pot would get about one teaspoon (5 ml) by volume. It is approximate, oyster shell is inert enough that measurement does not have to be exact. The crushed oystershell available here is just oystershell and it comes in 25 pound bags at Farm & Fleet or the Feed Store.


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## Jorch (Feb 28, 2009)

Interesting thread! Learned so much from the discussions. 

I've repotted my armeniacums/micranthums/vietnamense following the suggestions given here... crushed limestone mixed with Dynarok in the bottom, live moss on the top.


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## SlipperKing (Mar 1, 2009)

Jorch said:


> Interesting thread! Learned so much from the discussions.
> 
> I've repotted my armeniacums/micranthums/vietnamense following the suggestions given here... crushed limestone mixed with Dynarok in the bottom, live moss on the top.


You be sure to keep us updated on your setup so we can learn as well!


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## Sangii (Mar 3, 2009)

my armeniacum (the one I posted in the photographs section http://www.slippertalk.com/forum/showthread.php?t=11230) has always been a vigorous grower (I've had it since 2004). it bloomed for the first time in 2006, put out a spike in 2007 that ended up with bud balst due to too high temps in the GH in winter, put out another spike in 2007, that I accidentally broke off, and put out 2 spikes this year

I grow it in a mix of 50% medium pine bark, 30% limestone and about 20% of small clay pebbles or seramis. I repot every 2 years in the spring, keep the mix moist at all times in summer, a bit drier in winter (but not completemy dry when the plant is spiking)

The plant seems to tolerate a wide range of temps : temps in my Gh in winter can go up to 30° C whern it is sunny, and as low as 10-12°C where the plant is at night. In the summer, the temps range is 18-38° C !

The plant is placed near the humidifier, and in a constant air flow

hope this can help


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## SlipperKing (Mar 3, 2009)

Thanks Lilo,
This surely does help. You have your plant in a plastic pot right? Have you ever tried or know someone who has tried the wire basket lined with coconut fiber plus a mix?


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## Sangii (Mar 3, 2009)

yes this plant is in a plastic pot. I have tried clay pots for my parvis but they dry out too fast in my GH. the plant has 11 growths altogether

No I do not know anybody around here growing armeniacum in a basket.

A friend of mine who has quite a few armeniacums also grow them in a bark + limestone/gravel mix

I forgot to mention that the plant is grown in very bright light, lots uf full sun in the winter


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## Rick (Mar 3, 2009)

Sangii said:


> I forgot to mention that the plant is grown in very bright light, lots uf full sun in the winter



I think I've mentioned that amount and timing of light for armeniacum (and micranthum) is goofy for thes plants. On the Antech website, you can see that for armeniacum, peak light intensity is during the winter (colder) months, and light levels are quite high. During the summer months a combination of increased cloud and canopycover reduces light levels.

TN winters are generally cloudy, so I usually start supplementing lighting in the GH to my parvis to make up for all the short, cloudy days.


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