How deep? - Orchid Board

Bolero · #1 12-18-2006, 03:34 AM

Hi guys,

I have a good idea on how to grow most things but I'm really getting into Paphs and am finding out I still have a lot to learn.

Potting them into Coconut Coir at the moment which seems to be growing well, I even have a sheath forming. Anyway the question is that I've been potting the mix to about the base of the plant. But once the potting mix settles it exposes the top of the roots (just below the base of the plant). Where should the potting mix go to? Should it be the base of the plant? Just about the base? Or is it ok to have the top of the roots exposed? The top of the mix dries out quickly so I'm worried about moisture issues.

Thanks in advance for your help.

Tindomul · #2 12-18-2006, 11:06 PM

I'm interested in this question as I have just acquired some coir myself. Was wondering how to use it.

weng · #3 12-19-2006, 05:43 AM

Hi Bolero,

You don't say what size coir you are using. As your coir settles, are you using coir as in agricultural peat alternative?

I don't know anyone who has grown orchids in that stuff, but trials with potted plants indicate that the surface dries out quickly, leading to overwatering.

Weng

Ray · #4 12-19-2006, 08:20 AM

Coir crumb is common in "mud mixes", and although I cannot grow anything but oxalis in it (not enough air flow for roots systems in my culture), our own "Littlefrog Rob" wrote an excellent article for the AOS about it several years back.

Back to the original question for a moment: I find that paphs do best when the base is at- or very slightly below the surface, not elevated above it.

littlefrog · #5 12-19-2006, 11:04 AM

Yes, coir 'peat' is suitable for orchid use... But like any other mix, you need to water it right. And when I use coir or sphagnum peat I usually add about 50% 'fluff' (charcoal, perlite, etc). The mud mixes can be tricky to use, and probably not suitable for all types of orchids. I don't use peat mixes for paphs anymore...

To the original question... All mixes settle a bit after repotting. For most paphs, I like to pot just a bit deep (half a centimeter, tops) to account for settling.

Wendy · #6 12-19-2006, 05:36 PM

I've never used coir...it scares me. I have bought a few plants in it but take them out asap. It was dry on top and soggy in the middle....you'd need to be precise about watering.

I also pot my Paphs at or just below the medium. I find the roots will stall unless they can find the mix right away.

Bolero · #7 12-19-2006, 06:27 PM

Hi again,

It's comes in a block and is a mixture of coir, chips and husks that break apart. There are varying sized pieces but mostly they are small to medium sized.

I'm surprised at just how well the cattleya's grow in it, with many new roots and growths this year I am expecting vast flowerings next year (it's a dream I have).

Anyway I grow outside in a warmish climate that has drying winds but I try to keep humidity up as much as possible. Bark is way to arid for paphs here and sphag is too moist, especially during our cool winters.

Even when the chips dry out they still retain some moisture inside, I pick up dry chunks but when I squeeze them the moisture is still in there.

Most of my plants are small seedlings in 70mm pots (some in 50mm pots) so they dry out fairly evenly at the moment. I am trying my larger plants in it as well and so far during summer it's working out and I have a sheath forming for the first time on one of my pink lanterns. I noticed one of my paphs had two new roots forming but the mix was fairly low in the pot (had sunk down) so I was wondering what could go wrong if they had to reach a long way.

I have now topped up a few pots and have even topped up a few cattleya pots as well........it's amazing how well some things grow in this stuff. Paphs are new to me though in many respects and I don't think I had them potted quite deep enough.

Thanks this has been quite informative and I hope others have learnt from it too.

;-)