Paphs. re-potting

[pikevi]

I re-potted some of the larger Paphs. today. I used a mix mainly consisting of medium bark and medium size coconut husk chunks ; slightly more of coconut husk. Both of them comprised of about 90% of the mix. The rest of 10% is a mix of perlite, charcoal and sphagnum moss.

I hope there is no major problem with this mix for Paphs.

[kmarch]

the mix is fine but as it does not contain much moisture retentive material, and as Paphs like it gently and evenly moist you should probably use the skewer methood or somethign like that to monitor your watering for the first few months to make sure they're not drying out.

[gore42]

I actually grow most of my Paphs in coconut husk chips (CHC) mixed with lava rock or LECA. Coconut, when watered thoroughly, retains a LOT of water, and then releases it slowly, which has been great for me, growing here in dry Colorado.

For more information about growing in CHC, the articles written by Bob Wellenstein at Antec labs are the best I've seen, with lots of raw data for those of us who like it . You can find them here: http://ladyslipper.com/coco3.htm

I should also mention that Hadley Cash of Marriot Orchids, the well known complex hybridizer, grows all of his Paphs in CHC mixed with LECA (and a small amount of charcoal).

- Matthew Gore

[Tobi]

Kevin or Matthew, have either of you heard of anyone using oyster shell grit
in a Paph medium to keep the Ph from getting too acidic?

[kmarch]

Yes I have. One of my orchid buddies here in Melbourne uses it though he says he uses it to add calcium rather than adjust pH.

[pikevi]

Tobi: I read about that in one of those sites I visited. I have no personal knowledge or experience with its use. But it struck me as very odd - to use it in orchid mix since CaCO3 is not that easy to braek down.

The reason I am writing this is there was a stipulation as to the percentage in the mix. The article was very insistent on that but I can't recall the number. But I will look for it.

May be kmarch can elaborate on that.

I am sorry I can't be definitive on the amount.

Gore42: Thanks for the URL. Very informative. But I have not seen those 'small' CHCs here. They seem to be quite useful since most of my paphs are small.

kmarch: I will increase the moss content substancially in my next mix. Thanks.

[Tobi]

I believe the person using this told me about 1/8 part of the oyster shell in the
mix.

[pikevi]

Originally Posted by Tobi

I believe the person using this told me about 1/8 part of the oyster shell in the
mix.

It seems right but I am not sure though. It was in % so it does not ring a bell. But I will search for it along with so many other searches I am conducting

[Tobi]

Thanks Pikevi, let me know if you find anything

[gore42]

I also use oyster shell or lime pellets in some of my paph pots, but I use it as a top dressing rather than as a component of the mix.

There was a scientific article published in the AOS "Orchids"magazine last year about using additives to help keep the potting medium from getting too acidic. I'll have to look up the month... I think the study used dolomite lime, though... not sure whether oyster was also tested.

- Matt

[kmarch]

pikevi,

I'm afraid I can't elaborate further as I've never used it. Furthermore, I'm not an orchid chemist. I've never measured the pH of my water or mix and have never given much thought to trace elements like calcium or magnesium although i have toyed with the notion of giving my Paphs a shot of Epsom salts.

[pikevi]

I hope it is on an experimental basis, kmarch.

Since there is no 'soil' in the orchid medium what would happen to the sulphur?

I have read that they work well for vegetable plants but they grow in soil.

Good luck

[kmarch]

I don't know about the sulfur

[pikevi]

I was just wondering about the toxicity of sulphur, kmarch.

Usually they use magnesium nitrate [Mg(NO3)2]. Epsom salt is MgSO4.

In the former formula every element can be made use of by the plant but in the latter I am not sure about the 'S', especially on orchids.

Just a suggestion for you to look into before trying it on orchids.

Good luck.