question about phal and dendro

[Vulpes Velox]

hello there
i have a question about my phalaenopsis and dendrobium nobile i havent been able to find answers to, so hopefully someone here can help me.

anyway, im quite new to growing orchids and just have a few. one of them is a phalaenopsis that have had flowers for a few months. they now fell off and the stems have turned kinda orange, but otherwise just standing there like before (not that pretty). do i just leave them or what do i do about them?... the plant seems healthy enough otherwise, just started getting a new leaf, and the old leafs are a nice green colour and strong.

about my dendrobium nobile. no flowers on it but its grown something like 20 cm in 2 months.. and on the side of an old cane seems to come a new one on the middle with roots sprouting out and such (its maybe 15 cm long by now), is this the plant doing an asexual reproduction since the flowers it had werent fertilized?