How to Bloom a Paph Druryii?

[A de Lioncourt]

I've had this guy a couple of years now, and he seems to be growing well, lounging around in the sun and sipping a fertilizer cocktail, but I can't get it to bloom.

I keep it at ~60F night-~70F day during the winter, and about 70-80 in the summer. In the winter, I water very little, just keeping the moss slightly damp, and in the summer I water and feed regularly. I keep it in the higher light part of my setup.

I appreciate all suggestions from people who have experience with this orchid.