Do Paphs need limestone in their mix?

[My Green Pets]

I'm reading how lots of Paph species grow on limestone, granite, or sandstone rock faces, in an alkaline environment.

Assuming the plants will grow best in a medium which replicates these conditions, how would I put together such a medium?

My only ingredients at the moment are medium grade bark and long-fibered sphagnum moss. Should I be on the lookout for limestone chips to add to the mix?

[King_of_orchid_growing:)]

Sandstone and granite are not alkaline in pH, they are acidic in pH. Limestone is alkaline in pH.

Certain Paphs appear to benefit from calcium supplementation or limestone in their potting mixes.

You can add some of the smaller limestone rocks into a mix with some medium grade bark. For some Paphs, it's as easy as that.

[vjo]

How do you determine which ones need it and which ones don't? What symptoms would you look for?...Jean.

[sbrofio]

Hi VJO, most knowledge thanks to reading.
I marked that calcium carbonate is for parvisepalum (armeniacum, michrantum et simialr but NOT for delenatii) and for brachipetalum (bellatulum, niveum, concolor).

[PaphMadMan]

There's a fairly extensive list and explanation of limestone loving Paphs here: Supplementing Calcicolous Paphs

[vjo]

PaphMadman.Thanks for that list I bookmarked it to make sure I can find it later. Now how to tell by looking at a plant, if that is what it needs as opposed to some other remedy. Thanks again...Jean

[King_of_orchid_growing:)]

Plant Physiology Online: Symptoms of Deficiency in Essential Minerals

The pics may not be of orchids, but the symptoms should be somewhat similar.

[orchidsarefun]

I use crushed oyster shell on those that need it, works well...

[Orchid Whisperer]

Originally Posted by PaphMadMan

There's a fairly extensive list and explanation of limestone loving Paphs here: Supplementing Calcicolous Paphs

Great link - thanks! Useful information even if you are not growing calciphile paphs at the moment.

[My Green Pets]

Thank you for that great link!