Dendrobium phalaenopsis with dying backbulbs

[Kaykay]

Just a quick question. How long do I leave them before removing? I have a Den phal with 12 pbulbs, of which 3 are leafless, and are gradually going yellow and showing definite death signs. One of these is showing signs of rot at the base- I've cut out the patch and treated with cinnamon, but my question is, how far do I keep them on the plant anyway? Will they all rot after turning yellow or is there something wrong with my plant that I need to deal with more drastically now? This is my first and only Den, so I'm really fairly clueless, and haven't found much info on this in books or on the net!

Otherwise, the plant seems happy. 2 new growths on the way, will probably need to be potted up soon, as root system is extensive.

Thanks for the help!
Kay
x

[King_of_orchid_growing:)]

Older canes will die back. It's natural. However, they should not be rotting.

If they're rotting there may be other problems involved.

You can leave the dried up canes for up to a year or two. Sometimes the canes look dry but they still have a little bit of life in them. So my suggestion is to not cut them off right away.

Unless, there's rotting involved, then cut immediately.

[Kaykay]

Thanks King!
I just wanted to check if it were a cause for concern or not. I was going to take it out of the pot it came in, and put it in a basket instead, so this is the opportunity to do it.
Kay