Re-potting Oncidiums

[Spook In Spain]

Many people say repot Oncidium Alliance orchids in sphagnum moss and many say Fir Bark media which is best as Spagnum moss is hard to get here in southern Spain.
Any tips on medium for repotting welcome:

[Silje]

I'll give my vote to fir bark. I'm never able to water correctly with sphagnum and always struggle with root rot if I for some or other reason keep them in the moss for longer periods of time.

Lately, I've come to like a combination of coir and bark. That seem to suit my watering habits pretty well.

[NYed]

What kind of oncidium are you looking to repot ? I like to grow mine in a mix of coconut husk chips. It has good moisture retention but also good air flow. Most of mine are intergenerics and are growing well in it. I have also have a oncidium sweet sugar growing in bark mix.

[tucker85]

I think watering and light are more important than media. At different times I've grown oncidiums in sphagnum and in bark as well as in coconut husk chips. All these media seemed to do well. The important thing is to adjust your watering to fit the media. Oncidiums like a little more water than cattleyas but do need to dry out during the fall and winter. I would use whatever media is readily available to you.

[orchidsarefun]

Tucker is 100% correct.
Another general guideline is that the "thinner"/finer the root, the finer the medium. I believe sphag is the universal medium providing you water correctly, but orchids with fine roots like some oncidiae and miltoniopsis should be potted in a fine fir bark mix and phals as the other example in a larger fir bark mix. The same principle applies to coco-husk chips. You will also need to appropriately amend the mix you use with sphagnum, vermiculite,etc....

[WhiteRabbit]

Glad you found us!

I've used fine fir bark mix, or fine coconut husk chips mix with good results.

[Spook In Spain]

Hi there thanks for the info, i have been told these are Oncidium Alliiance minature orchids, they are just under a foot high in small clay pots