moldy oncidium in S/H

[kkdcalgary]

I repotted an onc. twinkle 'red fire' in S/H. It's greatly enjoying the S/H but the old roots are growing this fluffy white mold. As you can see in the pic the roots are actually quite happy and I think the mold is from old roots I didn't want to snip off. Is it worth it to be more aggressive about snipping the old roots to avoid worst moisture/fungus problems in the future? The roots are so delicate I'm pretty sure I'll do more damage than good if I try to go after it...

[DelawareJim]

A little hydrogen peroxide or a fungicide should take care of that.

I've found you can be pretty aggressive with removing oncidium roots. I have a 'Sharry Baby' that had some issues and I cut off all the roots and transferred to S/H. While I had to stake and rubber band the plant to the pot to keep it in place, it transferred just fine, although a bit more slowly than other oncidiums I've transferred.
I wouldn't recommend such drastic measures, but it is doable.

Cheers.
Jim

[nenella]

Jim, just my
You definitely need to get rid of the mould. I assume it's from the dead roots being left too moist for too long. Start by doing as suggested above..personally I would clean up & get rid of the mould and boil/bake the pebbles, and replant having cut off all the brown dead roots.
Also I would make sure the New roots get green and then dry to white before re watering.. even if it means watering every day, but making sure the roots and bottom of the p/bulbs remain dry... (&/or ventilate very well after watering) this should encourage even more new root growth. .. which will get you healthy new growths/shoots/flowers as long as you make sure more new roots grow & existing keep on growing.. Good luck & keep us posted.

P.S: a good idea is to also soak in a rooting hormone like KLN ..which helps incite new root growth.