Thanks for your feedback, Arthur. It is indeed one plant. I don't know how to discern the rear vs front of the plant, so can't answer that. I just know the immediate yellowing occurred within days repotting (into the standard bark medium from a local BigBox store. Up until repotting, the entire plant was healthy and flourishing -- lots of firm, green leaves.

ETA: I just checked the plant and am now concerned that cane pictured is now showing signs of the same yellowing starting, and the cane itself is appearing to pucker. Should I pull the plant out and start over? Repot?

The front of the plant is the largest growth. Healthy plants might have four or five fully leafed canes and a few more at the back of the plant with no leaves.

I started growing these after visiting an orchid show in Tropical Queensland. They are in a glass-house and I have had only moderate success with them.

Best under-potted, watered in the morning and need to dry by nightfall. They decline quickly outdoors here and I suspect the same would happen in Houston.

The yellowing occurs (I think) because the plant is trying to survive and takes nourishment from the back of the plant.

Make sure you have plenty of drainage holes at the base of the pot. Not sure in the growth cycle when it will grow new roots from the newer canes/pseudobulbs. Maybe the local Orchid Society can provide a few tips.

I have several of these dendrobiums and usually find if they yellow immediately, it's the stress from the transplant. Were the roots in good shape and did you soak the media for a while before transplanting? I know they hate being cold and I live in Michigan so in the summer I place them in a sheltered area outside but have to bring them in before any of the other orchids in the fall. I've found mine seem to do better in a type of stone media rather than bark for some reason. I have them in pots with a lot of drainage holes in the sides and bottom. Old canes will die off and turn brown eventually but still give nourishment to the new parts of the plant so I leave them alone and don't cut them off. Not the prettiest with old canes thrusting out in all directions but they always bloom every year and sometimes twice a year. My oldest one is probably about 12 years old.

Thanks again, Arthur. I'll be sure to do more reading. The orchid is kept indoors on a north-facing, bright window.

Mary: thanks for taking the time to reply. The roots were in fairly good shape -- had to snip some of the obviously dead ones, but left a lot intact. And, yes, I did pre-soak the bark media for several hours; and the pot does have drain holes at the bottom (per Arthur's recommendation). I'll just watch the plant and keep my fingers crossed -- I'm feeling like I should have just left it alone. :/

If you can, try putting it outside in a bright, warm spot. Do not overwater. It looks like those yellowing canes are dying. Your best bet is to support the newest growths by cutting back on water and fertilizer. Dends do not like their roots disturbed.

I would keep it warm and bright and hope for the best.

Jane

Thanks so much, Jane -- all good information. Note to self: do research before repotting! I'll set it outside tomorrow -- today's weather is floody rains, thunder, lightning, heavy winds, etc. :/

A happy update to report: phew!