Why is armeniacum such a huge pain?

[John M]

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.

 

[Eric Muehlbauer]

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

 

[TyroneGenade]

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

 

[kentuckiense]

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.

 

[Corbin]

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.

 

[John M]

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.

 

[Rick]

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.

 

[Rick]

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.

 

[cnycharles]

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

 

[biothanasis]

TY all for the very interesting info!!!

 

[Rick]

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.

 

[Eric Muehlbauer]

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

 

[cnycharles]

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

 

[SlipperKing]

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.

 

[Eric Muehlbauer]

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

 

[user 9150]

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.

 

[Leo Schordje]

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

 

[NYEric]

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

 

[Corbin]

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.

 

[Eric Muehlbauer]

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