Q: I have several Cattleya and Oncidium orchids which refuse to bloom. They are outgrowing 6″ pots and are in heated greenhouse with a 55F minimum temperature. I am sure they receive enough light because they are right next too some Brassavola digbyana and Brassidium, which bloom profusely. I feed very two weeks with a 30-10-10 fertilizer and use 10-30-30 every fourth feeding. The plants are in fir bark. Last winter, I quit feeding them and watered them less in an attempt to rest them. Still, there were no spikes. What am I doing wrong?
A: As for the Oncidium, it is difficult to say just what your problem is because most plants of that species are relatively free-blooming. Sometimes a particular clone is not good genetically and just does not flower. It is best to buy either plants in bloom, plants bloomed previously, or those known to be free-flowering. Brighter light could be the answer.