Has anyone here saved onion seed? I've got a couple of OP strains, and several from one in the garden now. It's mulched and covered, but this idea was sort of seat of the pants and now I'd like to know how to REALLY do it. LOL
The onions still had thick necks at the end of the season, so I'm not hopeful. Next year I'd like to do better.
Well, I am basically the same zone as you. Based upon that, I would guess that you may have to bring in the sets and then put them out? But, that being said, I have missed some onions in my garden and they did return in spring...
I have had some of the perennial onions, like Egyptians and I just leave them be.
They come up, bloom, and set.
I would think if you are planning to leave onions in, you would just plant them the same time as any other onion and never pull them at the end of the season. I would mulch them for protection.
If this is a rare heirloom, it may be what you will have to do to sustain your seed supply. If not, maybe it is simpler to just buy the seeds annually?
I don't know how many seeds you can retain from a seedhead, so maybe it is only a matter of overwintering a few plants.
Maybe someone with more onion experience will chime in here. ;)
If your winters are truly 5 b, I don't think you would want to overwinter. Years ago in zone 7. we would harvest onions in late summer, store them, and then reset some of them in the spring when they would promptly go to seed.
Actually a large percentage of sets ( the small dry bulbs) as opposed to plants are OP. If you can find the cultivar name, look it up in Plantfiles and you may be surprised that it is an OP. Virtually all plants, however are hybrids. Sets are notorius for bolting, so you can probably get plenty of seeds without any more effort than just just letting the seedheads go until they dry.
I've pulled the plastic and straw mulch off my bed today, and-- wonder of wonders--some of the onions have made it through! I've got about 7 that are putting up fresh shoots. I think I did everything wrong--didn't dry them off for two weeks, and scratched in compost just before mulching--and some still made it. =0) Of course, the others are gross, rotting, slimey disgusting things, but hey... It was a warm winter, so that was a help; we never got below 5* as far as I know. Next winter I am definitely going to build a mulch cage, and harden off a bit better.
So it looks like I just might be able to get some seed from these guys this year.