I have hundreds of them. Started with 18 bulbs, on the mark down counter in K-mart, 30+ years ago, in late November.. Planted immediately, and they are reproducing like weeds! I've given hundreds away, and donated a bunch for a fund raiser.
Yes they do spread. The mistake most people make is cutting them down right after they bloom. I wait until they start to turn brown. If you cut too early they won’t bloom the next year
