I had this plant quite a few years ago and it was mounted on cork. This Dendrobium needs a dry, cool, winter rest (I think I withheld water for about 1-2 months). It also needs bright light to flower well. Your's probably isn't growing now because this should be its rest period. I would leave it in the pot until you start to see new growth/roots developing this spring and then mount it to cork.

BN

ok,birding nut,thank you for your answer.i will follow your instruction.,do you know when they typically bloom?

They usually bloom in the spring after the winter rest. I would start to water mine when the buds would be half grown.

BN