Thanks, everyone. Ceci, I too have a very large, very old Dendrobium, and it has never missed a beat, flowering every years with multiple spikes similar to yours. It has now been in constant bloom for over three months and still has unopened buds.
Tarev, these Dens were all potted with their cane/canes just at or above the bark mixture. That's one reason I didn't trim their roots when they arrived. This enables me to anchor the root without burying the cane(s). Though I mist my plants every few days, and they are all in my orchid greenhouse, I don't over-water the newly potted plugs and thus their potting medium stays on the dry side. I just don't know. I have contacted my grower in Maui, told them what happened, and asked for advice. Ken
