Stupid Paph-question nr 253 - oyster shells

[The Mutant]

I've ordered a Paph. philippinense var. roebelenii and if I've understood everything correctly, this guy is a calcicolous Paph so I've planned to add some oyster shells to its substrate. Should I mix it into the entire substrate or just put it on the surface, and can I use the same crushed oyster shells that are used for pet birds?

[PaphMadMan]

Paph. philippinense is indeed a calcicolous Paph. Top dressing with crushed oyster shell is often recommended, and certainly a valid and common way to go, and the stuff intended for pet birds is just fine. Or use dolomitic limestone, or mix it through the medium. It probably doesn't make much difference, but a top dressing is certainly easier without having to repot. Maintain a balanced fertilizer program too of course, or there is no point.

Before you go for it though, make sure you do not have a hard or alkaline water source. The extra calcium really isn't needed then and could add to a problem rather than correctling a deficiency.

[The Mutant]

Thanks for your answer! Then I'll order some crushed oyster shells for it. We have rather soft water in my municipality so I think it'll be happy to have some extra calcium added.

I'm feeding my Phals and Paphs a well balanced fertilizer and also seaweed extract. Later on I will be adding magnesium and calcium to all of my orchids, just to see what they think about it.

[kavanaru]

you can also mix the oyster shells in the substrate... both way work good (I prefer mixing them in the substrate as it seems that the roots like to attach to them)

I got a book of Harold Koopowitz - "Tropical Slipper Orchids..." and there he states that it is not necessary to add oyster shells or any other Ca supplement to the substrate for Paphs.
Apparently he tried it both ways (adding and not adding) and there was no difference.
What do you guys think about that? It seems like he has some authority in slippers and his advice should be reliable, right?

[The Mutant]

Originally Posted by kavanaru

you can also mix the oyster shells in the substrate... both way work good (I prefer mixing them in the substrate as it seems that the roots like to attach to them)

I plan to add it to the substrate since I'm going to re-pot it anyway (unless they are in bloom of course, but I doubt that).

Originally Posted by orchideya

I got a book of Harold Koopowitz - "Tropical Slipper Orchids..." and there he states that it is not necessary to add oyster shells or any other Ca supplement to the substrate for Paphs.
Apparently he tried it both ways (adding and not adding) and there was no difference.
What do you guys think about that? It seems like he has some authority in slippers and his advice should be reliable, right?

Geez, there's no wonder it's so difficult for us newbies when we get such contradictory messages. *shakes head*

I'll add the oyster shells for this guy and leave it at that, it can't hurt I figure.

[kavanaru]

Originally Posted by orchideya

I got a book of Harold Koopowitz - "Tropical Slipper Orchids..." and there he states that it is not necessary to add oyster shells or any other Ca supplement to the substrate for Paphs.
Apparently he tried it both ways (adding and not adding) and there was no difference.
What do you guys think about that? It seems like he has some authority in slippers and his advice should be reliable, right?

I woud agree only if you have very healthy plants and a very well balanced fertilizer and a lot of experience growing Paphies... my experience, and you can also have similar feedback when reviewing the threads in Slippertalk (the forum specialized in slippers!), is that adding oyster shells, calcareous stone or any other similar calcium holding material to the medium helps not only as a source of calcium, but to increase the pH around the roots... If you ask the experts in Slippertalk or any other paph experts you know, you will see that most of them add something similar or use a strong source of calcium in the fertilizer (Calcium Nitrate or Sulphate, Dolomite, etc...)

Originally Posted by kavanaru

I woud agree only if you have very healthy plants and a very well balanced fertilizer and a lot of experience growing Paphies... my experience, and you can also have similar feedback when reviewing the threads in Slippertalk (the forum specialized in slippers!), is that adding oyster shells, calcareous stone or any other similar calcium holding material to the medium helps not only as a source of calcium, but to increase the pH around the roots... If you ask the experts in Slippertalk or any other paph experts you know, you will see that most of them add something similar or use a strong source of calcium in the fertilizer (Calcium Nitrate or Sulphate, Dolomite, etc...)

Great! Thank you, that's what I wanted to hear. With all the additions and fertilizers I usually try to avoid unnecessary stuff, so to not make things worse by trying to do good (yes, sometimes it happens).

[Leafmite]

No question is stupid, Mutant. The more we ask, the more we learn and help others to learn. Good luck with all your new orchids! : )

[The Mutant]

Originally Posted by kavanaru

I woud agree only if you have very healthy plants and a very well balanced fertilizer and a lot of experience growing Paphies... my experience, and you can also have similar feedback when reviewing the threads in Slippertalk (the forum specialized in slippers!), is that adding oyster shells, calcareous stone or any other similar calcium holding material to the medium helps not only as a source of calcium, but to increase the pH around the roots... If you ask the experts in Slippertalk or any other paph experts you know, you will see that most of them add something similar or use a strong source of calcium in the fertilizer (Calcium Nitrate or Sulphate, Dolomite, etc...)

Thank you Ramon! It's always good to know why one do certain things.

Hmm... This leads to another question though - when it becomes available I will buy Calcium Nitrate and give this and Magnesium sulfate to all of my chids, should I stop using the oyster shells in the substrate, or should I continue using it? I THINK I should continue, but I want to hear what you guys have to say about it.

Originally Posted by Leafmite

No question is stupid, Mutant. The more we ask, the more we learn and help others to learn. Good luck with all your new orchids! : )

Thanks Leafmite. Sometimes it feels like all I do is ask! And thank you, I really need all the luck I can get with my invasion.