How are spikes produced?

You'd think I'd know this by now, but I took a couple of years hiatus from orchids after only being involved with them for short period. Anyway, my question is, how are spikes produced on different orchids? For instance, when a new Dend. cane has finished hardening and is fully grown, but no spike emerges...is that is for it, then? Or do the canes remain barren until it just feels like sending a spike up all of a sudden? And as for Catts, kind of the same question. When a new leave unfolds, hardens and there is no sheath - is that it? Or are sheaths produced later on whenever it decides to do so?

I don't grow dendrobiums but for cattleyas, the sheath will form when the psuedobulb first grows out. If there's no sheath it won't grow one later. But spikes sometimes form on psuedobulbs that don't have sheaths. Just because a psuedobulb has a sheath does not mean that blooming in immanent. It can be months before buds form in the sheath and you'll always get some sheaths that buds never form in. The best indication of when a cattleya will bloom is the time of year. I keep a record of when each catt blooms so I have an idea when to look for new buds. Good luck.

Orchids are weird my Dendrobium has sever canes mature and only one is sending out a spike on the other canes I see the tip of what looks like a spike however every day then turning to weeks those spikes don't mature staying the same .. perhaps they still deciding what to do or all the energy is being draing by that solo can putting out a spike... I scratch my head