From my reading, it looks like if you store them at temps over 50 degrees for a month before planting, and only plant sets that are smaller than a quarter (some sources say nickle), they will produce bulbs rather than seed. But yes, if you want to harvest seed AND bulbs, you could plant all of your sets, regardless of size. I don't know about a perpetual bed, though. Wouldn't you want to renew the soil every year? Onions like it fairly rich.

Catherine

Catherine, thank you for your reply.

Actually, I got this idea for a permanent globe onion bed from William Woys Weaver. He's a vegetable historian (!). He wrote an article on how about 150 years ago commercial onion growers used the same beds along the mid-Atlantic coastal plains year after year.

I'm always looking for easier ways to produce food in my small garden so I thought I'd give it a try. I'm wondering which of my 3 onion varieties would be best to use for this experiment.

The bed could be enriched by simply top-dressing with good compost, since onions are shallow-rooted (?).

"Permanent" is not the same as "perpetual."

I have permanent alliums beds, as do several others here. All that means is that we use them, year after year, for growing garlic and onions, amending as necessary.

A perpetual bed, on the other hand, would be one in which some plants were bulbing while others were self-seeding. As Catherine points out, this is less than feasible with heavy feeders like onions, because they would rapidly deplete available nutrients.

Thank you for your input, gardenlad. I can see that this idea needs more work. Well, I'm sowing my globe onion seed into containers today for transplanting out into garden later in the season. Lots of time yet to think about where I'll put them and for how long. Thanks again.

One other point that might be germane.

Jeptha Yoder, from whom several of us get Bottle Onion sets, doesn't sow seed until August. He's in the greater Lancaster area, so that might make more sense for you than what somebody in Vermont is doing.

Also, why are you bothering to set seed in flats for transplanting? To produce sets, just direct sow, very thickly, and let 'em rip.

When your onions start the blooming process do you cut off the tops or leave them on?

Thank you