Brown fungus/mold Phal roots please help

[cajander13]

Hi my name is Adam and I am relatively new to orchid growing. I have about 20 phals that have browning roots that become dry and twig-like. This only happens on the exposed roots above the surface of the medium. There is also a white fluffy fungus on the undersides of the roots that haven't completely turned brown. All of the roots in the medium are healthy. I have not been overwatering, and even when I bring home a new phal, within a few days the roots start to get brown spots forming on them. I have a 0.9% sulfur fungicide but don't know if I should use it. Any help would be greatly appreciated.

Thanks,

Adam

[BobInBonita]

Can't say for sure but:
Overwatering gives black soggy rotten roots.
Underwatering can cause dry hard roots, especially aerials that can dry more completely.

How's your humidity? Increasing it might help.

Are the plants otherwise healthy? If so, I wouldn't worry about it too much. Phals don't like change and simply bringing them home from a high humidity greenhouse can cause things to happen.

Best of luck with these and your next twenty.

[Zoi2]

If your phals are planted in sphag moss, it retains quite a bit of moisture in the center under the roots. You may be getting mold/fungus from that.
Joann

[BobInBonita]

Thanks, I had been looking at this as mainly a light issue, but you're right about the moisture. I should dig into one of the baskets and see if something unexpected is going on there.

Most phals, and the affected ones, are in slat baskets lined with screen (so finer bark doesn't fall out). I generally put a "lump" of sphag on the bottom and cover with a layer of bark. The plant then goes on top of this, with the roots covered with more bark mix (contains charcoal and some coarse rock-like material). I've had good luck with this layering method for phals for some time now. The idea was to have a gradient of more moist to pretty dry, so the orchid could send roots where it was happiest, and also would provide a little extra dry-season moisture.

This year, with the abrupt change from wet to dry season (about when I moved them) it might have added to the stress of the move and light changes..

[cajander13]

So should I use the sulfur spray for the fungus?

[Zoi2]

What kind of sulfur spray is it? A general purpose garden fungicide? I wouldn't think it would hurt, but I would probably also repot in fresh media.
Joann

[silken]

Can you post a picture or two?