# Growing slippers in stone or gravel



## TyroneGenade (May 30, 2013)

Hello,

Continuing my research into growing substrates for slippers I would like to know what experiences people have and what their thinking is about growing Paphs and Phrags (etc...) in stone or gravel.

I have been experimenting with crushed brick and Table Mountain sandstone gravel with some Ok results.

The Brachies and Bulldogs seem to do well in the crushed brick but the Bulldogs need some leaf litter mixed in. I have also tried Bulldogs and insigne in sandstone gravel with some success. Again, I had to add some shredded leaf litter into the mix. Root development is good and so is growth. I made the mistake of adding some Osmocoate to one plant and burnt the roots terribly but it is now recovering nicely.

I have a topperi which wasn't doing so well in its mix of bark, and then brick so it is now in 6--7 mm gravel with some leave litter and is pushing out new roots. So far so good.

What are peoples thoughts about growing in stone, watering and fertilization?

Thanks


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## eggshells (May 30, 2013)

I have two phrags growing in higromite. So far nothing is happening. But it they are only a month in. I hope they will do something soon.


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## Dido (May 30, 2013)

I put some seedling in different mixes and want to see what happens, as our far north friend has shown that his seedlings grow like crazy in gravel. 

Will put it on when I can say something


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## Rick (May 30, 2013)

I've been using a high percentage of very coarse limestone gravel in my baskets with good results on a wide range of paph and phrag species.

They get more water than pots, but I think the more water the better for growth (although more labor).


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## ehanes7612 (May 30, 2013)

is it me or do brachy's seem to grow good in anything?


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## Ozpaph (May 31, 2013)

ehanes7612 said:


> is it me or do brachy's seem to grow good in anything?



It's definitely you. Brachies aren't easy for many of us........wish I knew why!


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## ehanes7612 (May 31, 2013)

Ozpaph said:


> It's definitely you. Brachies aren't easy for many of us........wish I knew why!



maybe its our water


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## Bjorn (May 31, 2013)

Just posted some results from vietnamense growing in limestone gravel (marble) I do a lot of growing in gravel, but normally together with some bark and sheetmoss and sand. Also it is not always limestone, depends on how the roots develop. many species do not like too much limestone. Howevers seems as if topperii can take pure limestone gravel. At least according to my topperiis  But this may be a result of thewater etc. etc. My irrigation water is always with nutrients(100-200ppm) and rather acid pH 5.5-6.5 and this could influence the tolerance towards limestone.


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## TyroneGenade (May 31, 2013)

Thanks Bjorn, et al for the info.


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## phrag guy (May 31, 2013)

I have a bunch of phrags in diatomite(semi -hydroponics) with a bit of moss they love it. I put some seedlings from flasks and the roots took right off.


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## Stone (May 31, 2013)

Ozpaph said:


> It's definitely you. Brachies aren't easy for many of us........wish I knew why!



Its the heat. They love it, they need it. Normal growing temps for most if not all is 20C minimum. The 15C min that we think is ok, is not. ( they will survive it but will not grow much and if you water a lot at these temps you get rot ) It's more like an extreme low for them. Give them lots of heat (and humidity) and they will grow. 22C to 32C or 35 even! Since building my hot box, (20 to 28) all my seedlings have resumed growth. I just hope I can afford to keep it up!


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## consettbay2003 (Jun 1, 2013)

After checking out the habitat for leucochilum it would appear that in nature 
they experience average day temperatures of 85F and minimum night temperatures of 73F for the entire year. After I met these requirements the improvement in growth was amazing. 

From my experience this is not true for bellatulum. They prefer similar daytime temperatures to leucochilum throughout the year but require much 
cooler nights from Nov. to Mar.


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## Ozpaph (Jun 2, 2013)

good advice, thanks.


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## SlipperKing (Jun 2, 2013)

I've been reading in my new book from our auction, Slipper Orchids of Vietnam of the limestone in which malipoense, vietnamense and micranthum are found in. The authors describe it as "crystalline-like limestone, marble-like" but malipoense var. jackii grows in a soft limestone. One other fact to note with vietnamense, 80-90% of the plants found were growing on a pure white limestone rather then the dark stained(oxidized) limestone all in the same area.


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## ALToronto (Jun 2, 2013)

SlipperKing said:


> One other fact to note with vietnamense, 80-90% of the plants found were growing on a pure white limestone rather then the dark stained(oxidized) limestone all in the same area.



It's usually iron oxides that colour limestone. Are we back to considering iron toxicity?


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## TyroneGenade (Jun 3, 2013)

Iron oxide is pretty tough (chemically speaking). Maybe the plants simply can't get a hold on it, or get access to the limestone due to the iron(III)oxide covering? Toxicity is an interesting hypothesis but I doubt the plants could dissolve enough of it to begin with...


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## SlipperKing (Jun 3, 2013)

I really didn't come across what the oxidation was a result of. It could be any number of things creating the preference for the white vs. stained limestone. They are found on the stained just not in mass numbers as is with the white stones.


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## TyroneGenade (Jun 3, 2013)

Maybe the darker limestone gets too hot?


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## ALToronto (Jun 3, 2013)

Iron oxides don't 'coat' limestone, they're part of the stone. Limestone is a sedimentary rock, so any contaminants are mixed in. I agree that temperature may also play a role. I wonder if all the plants on dark limestone are growing in the shade.


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## goldenrose (Jun 3, 2013)

ehanes7612 said:


> is it me or do brachy's seem to grow good in anything?


It's you, unless you consider anything to be that, that has good of fast drainage. 
They're pretty much naturally found on limestone outcroppings/cliffs with leaf litter so it makes sense to me. 
As Stone says, it's the heat, I'd agree. I've purchased a grow room for my basement, the cool growers will spend the summer there & then come fall I'll switch them back to the GH and the warm growers spend the winter in the basement with nighttime lows of 62.


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