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.

[DeaC]

Originally Posted by 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.

Would eggshell have any benefit?

[King_of_orchid_growing:)]

Originally Posted by DeaC

Would eggshell have any benefit?

Maybe if it was crushed into powder, idk.

[Hiester]

Originally Posted by DeaC

Would eggshell have any benefit?

I was wondering when someone would ask. Roy (orchid grower on YouTube) says his granny in Thailand always included a few crushed egg shells in her orchid potting mix, i.e. for any orchid she was potting up or repotting, so he does the same. Someplace else I read the shells should be cleaned of any membrane still adhering to them.

My mother didn't grow orchids, but she had a lot of houseplants. She always included a little bit of coffee grounds and crushed eggshells in her potting mixture for house plants.

[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

[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.

[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