Phal with discoloured leaves - Orchid Board

arianeos · #1 05-07-2018, 11:10 AM

Hey guys. So I rescued this phal as one amongst a bunch of about 16 from a friend in mid-March. Almost all of them had root rot and lost >50% of their roots when I repotted them from their 100% sphagnum into a current bark/perlite/leca/sphagnum mix (predominantly bark). This one is the only one that seems to still be struggling a little bit.

It has 4 roots left, about 1.5-2" long each. I cut the flower spike off about a month ago, but still don't see any signs of new root or leaf growth. It currently has 7 leaves, the bottom 6 of which are in various degrees of being spotty yellow, leathery, and a little bit sunken. The spots are completely dry, no foul smells anywhere. The top leaf is the only one that currently appears unaffected and I'd like to keep it that way if possible. I only noticed the discolouration creeping up over the past week or so. All the leaves, including the healthy-appearing one, looked leathery before I started daily misting of the sphagnum I have covering the root zone.

Watering: when the pot has no more moisture visible inside on the bottom and with a skewer I have sunken in by the stem of the plant. I coated the top of the pot with a layer of sphagnum that I mist at least once daily to keep the very superficial root zone from drying out while I wait for the plant to grow new/more roots.

I have four photos below for you guys, one of which shows the affected plant next to its healthy mericlone. The rest of the time, they sit on separate tables across the room from one another just in case this is infectious of any sort. I'd appreciate any ideas you guys have since I've only run into stem/crown/other rots before.

Ray · #2 05-07-2018, 12:13 PM

Based primarily by the appearance of longitudinal "ribs" in the leaves, I'd say the plant is simply not getting enough water.

Phalaenopsis prefer to be evenly moist at all times, but the mix needs to be airy, too. You description suggests the latter is not a problem at all.

I suspect you are yet another victim of the incorrect lore that "orchids have to dry out between waterings". An orchid in nature - especially most phals- is very likely dripping most of the time. The problems come in when we pot them up in too dense of a potting medium, then allow it to be saturated, so it suffocates the roots. Allowing it to dry out between waterings is a way to compensate for that with lousy media, but it's not the best for the plants.

arianeos · #3 05-07-2018, 12:46 PM

Thanks, Ray. I'll increase the waterings on this guy and see if that helps since his roots are noticeably much shorter and fewer in number than the others. I did notice this morning that his roots are actually grey, in contrast to everyone else in the batch and my prior phals who are all nice and bright green still.

I've never had phals with this few roots from rot before, so it's new territory for me. I appreciate the advice.