Which is best for seedlings, bark or moss? - Orchid Board

cythaenopsis · #1 08-31-2011, 04:27 PM

Every store that I've seen selling plants have their orchids in a sphagnum moss potting mix. Only a few had bark, and generally they were species other than phalaenopsis that were beyond the seedling phase.

I have 3 seedling orchids, all of which I've been told prefer bark (encyclia, oncidium, and cattleya hybrid). However, as seedlings I would think it's important for them to have a little extra moisture until they achieve a certain size. In fact, all three came with their roots in a clump of sphagnum moss. For the past 4 weeks they've been potted in moss and I've been attentive to proper watering (letting them dry out enough in between [see photo]). So far so good, they appear healthy. But now I'm wondering when would be the best time to repot them with a bark mixture. Any suggestions?

Wjs2nd · #2 08-31-2011, 04:39 PM

I know it can be hard for orchids to go from moss to bark due to the change in humidity. Usually you want to do a 50/50 mix for a year and then a straight change to bark.

camille1585 · #3 08-31-2011, 05:06 PM

Actually I find that sphag works very well for seedlings, mainly because their pots are so small that the sphag dries evenly, unlike in large pots. Your Oncidium seedling should especially like it, they enjoy being kept on the moist side. I've grown out mostly Phal and Onc seedlings, and I've never had trouble with the sphag to bark transition. Just need to keep them a bit wetter than usual until they get some new roots into the bark.

cythaenopsis · #4 08-31-2011, 05:41 PM

^ Thanks for the tips, Wjs2nd and Camille.

Good to know the moss will be fine for now. I'll keep it in mind to do a 50/50 bark/moss mix later on... is it best to do a layer with one on top of the other, or sort of mix it all together?

camille1585 · #5 08-31-2011, 05:49 PM

mix it altogether. If the sphag is in long strands it's better to chop it into smaller pieces so that it mixes into the bark better.

WhiteRabbit · #6 08-31-2011, 06:42 PM

I don't have a lot of experience with seedlings - but do think moss is a good choice - as Camille said, small pots dry faster than big ones, and baby plants don't handle underwatering as well as mature plants - just be sure not to overwater!

Bud · #7 08-31-2011, 06:51 PM

I would go for the moss...I dont have to water and fuss with the seedling plant all the time...

camille1585 · #8 08-31-2011, 07:10 PM

Not sure if sphag's the best for the Catt though, they like to be in an airy medium that dries quickly.

cythaenopsis · #9 08-31-2011, 10:10 PM

Quote:

Originally Posted by camille1585

Not sure if sphag's the best for the Catt though, they like to be in an airy medium that dries quickly.

It's actually a Catt hybrid, so I'm not sure how much a like it is with respect to the medium. I did make sure not to pack it too tightly and it does dry out in about 3 days, only 2 if I leave it by an open window.

PaphMadMan · #10 08-31-2011, 10:18 PM

The best choice will depend on the species or hybrid involved, the age of the seedlings, your growing conditions, and the care you can give them - and many other factors. In almost all cases what medium you use isn't all that important as long as you can adapt your watering practices and cultural conditions. Seedlings of almost any type will do better with slightly higher and more even moisture than mature plants. There is never a clear single best choice of medium for all circumstances.