In a home garden situation most members of the Onion Family are very easy to save for seed because we collect the bulbs, (garlic, potato onions, tree onions, shallots) store them and replant in autumn /winter or early spring.  Others we just keep on dividing up (welsh bunching onions, multiplying leeks, multiplying spring onions).

The only species we are likely to be collecting seed of are the leeks (A. ampeloprasum) or the seeding types of onions (A. cepa). As they cross within species this means we can only grow one variety from each species, and if you’re planning on keeping your lines of seed strong for the long haul then you’ll need to grow a minimum of 50 plants to seed of both the cepa and the ampeloprasum species. I would suggest you plant several hundred onions, mark the 50 most true to type for seed saving and eat the rest.  It works best to harvest all the onions in summer; choose the best 50 for seed and plant them again in early spring to go to seed. 

 

Flies and bees are the primary pollinators, not the wind. Isolation distances can  be up to 5 kms (see “Seed to Seed”) depending on geography. My feeling is that 5 kms applies when one is planting acres of seed and you’re on the Canterbury Plains with no hills or valleys! I find that far smaller distances work where you have populations of only fifty and you have small valley systems and loads of hills and trees. We’d love to hear of your experiences.