| Nancy, if the plant does fall apart when you repot, you could pot the pieces up separately or you could leave both pieces in the same pot, which ever you prefer.
Do not remove the rootless back bulbs unless they are dry/brown or mushy. Backbulbs serve as energy reserves for the rest of the plant and benefit the plant even if they have no roots.
when you unpot the orchid, examine the areas that look dead, feel the rhizome to see if it is firm or if it is broken, mushy, or crumbling. Firm and crisp is healthy. Also examine the roots. White-ish, cream-coloured, greenish, and firm and crisp is all good and healthy. Leave those roots be. Grey, dark brown, black, mushy, not firm, these are all signs of a dead root. You can remove these.
Apologies if i've told you things you already know. Let us know if you have more questions.
__________________  |