Limestones for Paphs?

[ksriramkumar]

Hi,

I was interacting with a few orchid growers/suppliers in Malaysia and they recommend to add lime stone, crushd egg shells for Paphs media..Probably to make the media more alkaline?. I did not know this before. I did not grow Paphs before. Is this a common practice adopted?

Sriram

[Brutal_Dreamer]

I add oyster shell to dress the top of the medium when I pot up new paph seedlings.

cheers,
BD

[raybark]

I will warn folks not to misinterpret what they see in nature.

ALL plants need calcium - usually simultaneously with magnesium. HOW MUCH they need varies fairly drastically, and some paphs are more demanding than others, and than other orchids. I believe it is the mineral they need, not what it may do to the pH of the medium.

Even plants that grow on limestone outcroppings tend to have their roots in mossy cracks in the rock, not on the surface so much. The cracks tend to be moist, and the decomposing vegetation and moss in them keeps the pH lower than one might expect.

[ksriramkumar]

Hi,

BD thanks. Do you add broken eggshells too?

---------- Post Merged at 06:19 PM ----------

Thank you Ray. very interesting point that lime stone does not mean alkaline media and needs some additional material like bark or coco chips to balance the needs.

[catttan]

I use crushed cockle shells in my paph media for those paphs that originate from limestone areas.

[EquestrisFan]

I use crushed oyster shell in the media for those that grows on limestone etc. in the wild. I've also purchased marble chips that I plan on using in the media when I repot next time, instead of the oyster shells. The species and one hybrid I have that like more calcium than others:

Henryanum
Helenae
Fairrieanum (it seems it can do without too)
Praestans var. gardineri
Phlippinense var. roebelenii
Michael Koopowitz
Malipoense

[PaphMadMan]

Supplementing with limestone or similar sources of calcium and magnesium is often recommended for some Paphs, but definitely not for others. Do an internet search for 'supplementing calcicolous paphs' and you should find a pretty comprehensive list of which species like it and which don't. Both pH and varying needs for these minerals may play a part, and can also be addressed in other ways. Dolomitic limestone gravel is possibly the best choice if you can find it since it supplies both calcium and magnesium.

[Katherine]

I sent you a link

[Brutal_Dreamer]

No, I've never used eggshells.

cheers,
BD

[zainal abidin]

Sometimes I'm using magnesium sulphate salt and Calcium nitrate as a supplement.