rtdrury wrote:
Has anyone cracked open jujube seeds in order to sprout the embryo?
All the ones I've opened are hollow. Is a hollow seed a viable seed?
I expected the embryo to fill the cavity like other seeds.

You might have seeds from a tree planted too far north. The tree
survives, but the seeds do not mature. My jujube berries, a few
hundreds a year, get close to turning color before first frost. I have
several little trees nearby, but the germination fraction has to be a
few percent only. If that is the case, you plant the shrub for its
looks (summer or winter, not a bad specimen), because the berries will
not make it.