Nanners from feminized seeds will at least give you all fem seeds (rodelization), so that's a plus. I recently found a couple volunteer plants from last years auto grow. They were in some used potting soil outdoors. I had a Norhern Lights that Nannered badly, so I moved it out of the tent into the garden. The buds must of seeded, and these were dropped in the soil. So I put them in pots in the tent with my photos, luckily the timing was right and the autos got 4 weeks of 19/5, before I flipped to 12/12, the autos are now as big as the photos which were planted a month earlier. Both, of course, are female.