I've been trying my hand at Vandas for the past year. Most are just babies an no where near blooming size, but two have previously bloomed as evidenced by the cut back dried flower stalk. These two have yet to bloom under my watch. So either in not giving them what they want yet, or it's just not their time/season to bloom. You're thoughts?
some bloom freely, and others bloom once a year. I am no expert, but the few that I have had that were once a year types bloomed in the spring.
Have you tried switching positions - swap one blooming with one non-blooming and see if the new one blooms? That is how I ferret out problems with conditions.
Most vanda alliance orchids bloom in the spring and summer. Ascocendas and vascostylis will often bloom more than once a year although some only bloom once. Vandas tend to bloom once a year but a few, like Pachara Delight bloom more often. During the summer months they like lots of everything, light, water and fertilizer.
There are quite a few newer hybrids that will bloom 3 or 4 times a year, so it all depends on which hybrid or species you have. Spring seems to be the main blooming time for most. Sometimes they can be stubborn. I have an asco Suksamran gold spot that dropped it's spike a year and a half ago when I bought it, and it still hasn't bloomed again. It's supposed to be free blooming.