Sphagnum moss for Dendrobiums and Cattleya

[scerdena]

I've recently re-potted my Phals and other orchids and have decided to put sphagnum moss on top of the bark (onthe phals) to prevent the new roots that are on top of the bark from drying out. Is this the correct thing to do? Or is it better for me to just mist the exposed roots daily? I've read here that it is okay to do this with the Phals, but what about the dendrobiums and new roots on the Cattleyas? Can I do the same with them or is it better to just let the roots take to the air?

Thanks for your help. This board is wonderful!
Shirley

[Brenda Aarts]

Hi Shirley, as we "speak" I am repotting a fair number of cats. and dendrobiums from spag to a bark mixture. When I first started growing I made the mistake of putting almost everything in spag and am now paying the price somewhat. I have found roots easily rot with spag. I know that you said that you would just put on the top, but it still may have the same affect. I have also observed that most of my healthier plants (dends and cats & phals) grow roots outside their pots and baskets and seem to like it that way....so I just leave them and they reward me with nice flowers. Remember that in the wild they are not pampered and grow where ever they can and alot of time their roots are exposed to the environment. Just my thoughts, hopefully some of the more experienced growers will chime in. Happy growing.

[King_of_orchid_growing:)]

A sphagnum moss top dressing for Cattleyas can be okay.

Top dressing for Dendrobiums can be a disaster.

Most Dendrobiums don't grow on moss covered trees.

Instead, most grow on trees covered in lichen.

There also happens to be a lot of pics on-line of Dendrobiums and Cattleyas growing in the wild. They're so easy to find that I'm just going to refer you to Google Images and do a search. You'll find it very quickly.

If your Phals have roots that are exposed to the air, and they're drying out, then it's okay to put a thin top layer of moss over the exposed roots and on top of the bark. But if nothing's wrong, then it's not necessary to put moss as a top dressing.

Remember...

I said sphagnum moss top dressing NOT potted in full sphagnum.

[camille1585]

What's wrong with a sphag top dressing for Dens? I have 2 Dens growing in 100% (high quality) sphag, and others in bark with a top dressing of it. They have very healthy root systems. It may not be natural (anyhow no orchids grow naturally in sphag as far as I know) but at least it works. And growing conditions on a tree are not at all the same as the conditions on my windowsill.

[Brenda Aarts]

Some people/plants don't seem to have problems with sphag, guess it depends on growing conditions & how quickly they can dry out etc... I for 1 know that it is only suited to a few of my plants (not cats and dens), stanhopeas, gongoras, coelogyne it's fine. Sometimes you just have to experiment a little I think Shirley to see what's going to work for you.

[King_of_orchid_growing:)]

Originally Posted by camille1585

What's wrong with a sphag top dressing for Dens? I have 2 Dens growing in 100% (high quality) sphag, and others in bark with a top dressing of it. They have very healthy root systems. It may not be natural (anyhow no orchids grow naturally in sphag as far as I know) but at least it works. And growing conditions on a tree are not at all the same as the conditions on my windowsill.

I guess the species I grow don't appreciate it.

Perhaps this is a type dependent topic for Dens.

That's why I wrote "can be" rather than "is" and used the word "most".

It seems like a cop out, but it's really not. I've found it increasingly difficult to be definitive all the time when it comes to speaking about certain topics nowadays. Things just aren't always clear cut the closer to the truth one gets to certain things.

The species I currently own are deciduous to some degree or another.

In fact, I'll list all my Dens that I currently grow.

Den. atavus
Den. harveyanum
Den. peguanum

They're all grown mounted.

The Den atavus and Den harveyanum are mounted pendulously.

The Den peguanum is mounted with the base of the pseudobulb flush against the cork bark.

None of them are currently grown with moss on the mount.

I've grown others in the past, but some of them didn't like the moss on the mounts or as top dressing on the bark either.

I can give you a list of those I grew in the past. It's not that extensive.

[camille1585]

I guess the difference with mine is that none of my deciduous/winter rest Dens are in sphag. The ones that are in sphag are a Den moniliforme and a phal type Den. On the other hand my Den aphyllum is growing naked on its mount!

[King_of_orchid_growing:)]

I forgot...

I also own a Den. kingianum.

This one's potted. But it's in Aussie Gold (diatomite/coconut coir).

It doesn't count.

No keikis btw. Just straight up growth from the base.

This one's getting to be specimen sized very quickly.