Oncidium spikes reblooming
 

I have a few Oncidium hybrids with spent flower spikes that I was just about to cut off today.

I have heard of Oncidium reblooming from old spikes, but never tried it.

These are just run of the mill hybrids in various mixtures of miltonia, brassia, Oncidium, cochloides and odontoglossum. Will they rebloom from an old spike?

I haven't heard of them reblooming. I wait to cut off spikes until they turn brown.

The only Oncidium types that I know of that rebloom on old spikes are the Tolumnias. But in general, I'm with ES... leave the old spikes until they turn brown, the plant can "recycle" the tissue.