OK to repot paph with active root tips?

[musicloveranthony]

I have a Paphiopedilum primulinum that i had to repot, today. It is currently in bloom (aren't they always? ). When I removed it from it's old home, I realized it had 3 actively growing roots. I'm fairly confident they would have, inevitably, gotten beat up a bit during the repot. would this be likely to stop their growth? I really hope that doing the repot didn't jeopardize their health.

Any responses greatly appreciated

[King_of_orchid_growing:)]

The repot most likely won't do it harm.

Have you ever tried growing in limestone instead of whatever commercially available potting mix you're using?

It'll probably save you the time of having to repot every year and what not. Limestone takes a very long time to degrade. And it's what they grow on in nature anyways.

I'm growing a Paph niveum in limestone with a little moss on top with some leaf litter added in. It's growing pretty well.

[musicloveranthony]

Thanks for the response. I've never used limestone. I use a bark mix from Orchids Limited that has medium fir bark, charcoal and sponge rock. I've actually thought quite often about using leaf litter in my mix but have never tried. Do you have a pic of the mix you're talking about that you could post?

Thanks, again

[King_of_orchid_growing:)]

Hopefully you can see it clearly. The white stones are limestone, OSH carries them and it's $5 a bag. The leaf litter looks like a bunch leaves cut in rectangular shapes. The moss is there too, but it's hard to see because I didn't put too much in there.

[musicloveranthony]

Thanks for the picture! That seems like a great idea. I usually pot everything in bark mix. The top half of the pot always dries within a day or two, while the bottom half stays very, very wet for a good week, or more. This causes most of my paphs to grow roots that spread horizontally, rather than making their way down into the base of the pot. How often do you end up watering the paph that you have potted this way? Also, does the calcium in the limestone mean you have to adjust your fertilizing regimen?

Sorry for all the questions, I know you have a lot of working knowledge

[stefpix]

Is limestone that rock that you can get at home depot for garden decoration??
is it good only for Paphs or also for Phals and Dens?

[King_of_orchid_growing:)]

Yeah, it's the same limestone that's used for garden decor.

Phals aren't normally lithophytes. However, some Dendrobiums are lithophytes.

An example of a Dendrobium that can grow as a lithophyte is Den kingianum. In fact, I use Aussie Gold for this species and it grows just fine. However next time I repot, I'm going to sift the medium for more Australian diatomite rocks (rocks that are formed from ancient freshwater mud and may contain large amounts of diatom fossils) and less coconut coir.

I chose limestone for Paph niveum because they grow on steep limestone cliffs. I positioned my Paph as best as I could in the pot like how I would mount my Phals, horizontally. This is how they grow in the wild, not upright, and this can allow water to dribble out of the crown. However, since mine isn't perfectly positioned horizontally, I have to be extra careful not to get water in there.

As far as fertilizing is concerned, I fertilize like many of the other plants in my collection.

[stefpix]

if you use limestone rocks or lava rock as medium do you need to water way more often than bark? usually those rocks are bigger than bark - how long will it take for the roots to stabilize the Dendrobium?

[King_of_orchid_growing:)]

I don't use "lava rock". I've used pumice or perlite mixed with SuperSphag. Pumice is an igneous rock. While perlite is just the porous glass form of a volcanic rock. But that's a whole different issue.

Yes, I water quite often with the plants I pot in limestone. Usually everyday or twice a day, depending on how much water gets used up. It's enough.

Root development and establishment is different for each species or individual plant I can't say.

However, if there's minimal root damage, and they're growing in a potting medium that is similar enough to their natural environment they shouldn't skip a beat and can start growing as soon as in a couple days. This is provided the plant doesn't mind having the roots disturbed.

[King_of_orchid_growing:)]

I forgot to mention, some of the plants growing in limestone have deciduous habits or go dormant. For example, I grow Habenarias in such a manner and will have to stop watering during the winter after all the leaves drop.

Paph niveum is in the section Brachypetalum and from what I understand may need to have water reduced during the winter. Luckily this is an easier one to grow.