Most of the discussion will deal with human efforts to increase hydrangea and will address both sexual and asexual aspects of propagation. Sexual Propagation Seeds Growing hydrangea from seed is easy, rewarding, and advisable if we are going to preserve the genetic diversity of the species.
Seeds mature two to three months after the fertile flowers' senescence.
They may be sown immediately. Dry storage is not necessary. Viability, however, is not diminished by it. Germination takes 10 and 14 days. Norman Deno of the University of Pennsylvania demonstrated that neither cold treatment at 40 F. for three months nor six months of dry storage at 70 F. had any effect on germination.