Possible mold on phalaenopsis roots - too early to repot? - Orchid Board

quaquaversal · #1 06-19-2014, 03:02 PM

Hi, all!

A little over a week ago, I noticed some white fuzz on the surface of my phal's medium, which I assumed was some kind of mold since the humidity has been so high. Considering I'd also been battling fungus gnats, I decided to repot, even though I last repotted just six months ago. I soaked a new, smaller pot, as well as the plant's roots, in a Physan20 solution. I had to cut some dead roots and used cinnamon on the cuts. I also changed the medium, from a sphagnum moss-based one to a coconut husk-based one (with some new sphag added to ease the transition). This new medium received a soaking in Physan20, too.

Now, a week after repotting, I've noticed what may be the beginning of the same mold on one of the roots. I'm a little annoyed—I haven't watered at all, just a misting on the aerial roots and under the leaves a few days ago, and I thought I had enough air circulation. I'm afraid another repotting so soon will stress it out. Perhaps I'm worrying too much about that, but could it be treated without repotting? Maybe more air circulation, as well? I appreciate any advice!

WhiteRabbit · #2 06-19-2014, 09:08 PM

You could pour hydrogen peroxide 3% through the media. But, hydrogen peroxide quickly becomes water, so I'd let the media dry before dousing it.

Misting the back of leaves and any roots at the surface wets the media - both chc and sphag are very absorbent, and hold moisture well; I would advise against misting, especially if you are having mold.

How quickly is the media drying? Are you letting it become nearly dry before watering? What are the temperatures it's in? I see you are in NYC - I imagine it's quite humid ?

quaquaversal · #3 06-19-2014, 10:05 PM

I think I wasn't letting it dry out enough when the humidity kicked in earlier this month. After I repotted and after the one time I misted, I left it by an open window in just its clear pot. The rest of the time it's sat in its new ceramic pot away from the window because I didn't want to expose it to too much light so soon. Maybe it needs more light and air circulation?

I'll try the hydrogen peroxide once it gets really dry. Thanks, and thank you for the welcome!

james mickelso · #4 06-19-2014, 10:35 PM

This mold won't hurt your plant. It is an opportunistic mold growing on dead and decaying organic material. The root is just the dead velamen. Just water when the plant needs it. The mold will disappear on it's own.

quaquaversal · #5 06-20-2014, 01:04 PM

Quote:

Originally Posted by james mickelso

This mold won't hurt your plant. It is an opportunistic mold growing on dead and decaying organic material. The root is just the dead velamen. Just water when the plant needs it. The mold will disappear on it's own.

Good to know! Thank you!