A couple of months ago, on a whim, I plopped a plain white onion into a glass of water. It sprouted and grew a long sturdy stalk, 22 inches long before I left town for the holidays. I returned home to discover that the plant had not only survived my ten-day absence, but had bloomed a lovely cluster of little white flowers.
This thing is still balanced in a glass of water, and shows no signs of ill health. It is absolutely gigantic: the bulb itself is four inches long, and the entire plant is 32 inches long, including the root system in the glass, the bulb itself, the stem, and the flowers.
I have never grown a plant in my life and know embarrassingly little about this. Will my onion self-pollinate and give me seeds? If so, how will I spot them? If it gives me seeds, can I plant them? How? How much longer will this thing survive without any soil? Can I start an onion farm on my kitchen windowsill?
If memory serves an onion bulb will divide into a couple more baby plants if it is shoved into the ground and left alone, I think it develops seeds the second year [I think it is the onion, I know it is one of the alliums that takes 2 years for seeds]
My 3 poor little chives have filled one of the large 5 gallon bucket sized terracotta planters over the past few years.
It probably won’t manage to self pollinate- but you might be lucky, if you want to try.
Normally allium flowers drop the pollen before the stigma (the female part) can be fertilised, but the flowers can open at different times on the same flowerhead, so you might be able to transfer a bit of pollen over- either let flying insects at it, or do it yourself with a paintbrush- just mix up the yellow pollen to different little flowers as thoroughly as you can.
If it does manage to set seeds, they’ll be quite visible little rounded black pellets- the size of an ‘o’. Let them dry completely, seperate them out from the chaff, and just stick a few of 'em in a pot of compost/soil in early spring, and keep them damp (not too wet). Give each seed a decent amount of space; growing them too crowded may well kill all of them. You can move seedlings to bigger pots after a bit if too many of them germinate.
You’d need a lot of space to grow many onions, but you might manage one or two, if you want to give it a go for the craic. I’ve only grown them outside, and I’ve never tried to save the seeds.
I’d guess your current onion probably won’t live long after flowering, I’m afraid. Bulbs grown just in water have a tendency to die, as they can’t ‘recover’ well from flowering.
