IMO long day or intermediate would be your best bet for bulbing onions. The short day onions would not bulb much if at all but would make good green onions.
YOPPER

With enough fertilizer, you should get a decent amount of tops and very small bulbs. I'd say just plant them close (I'd also check just where in China they came from ... I agree that normally seed planted in October should be a short day variety but you might just get lucky so it might be worth a chance to try and start some inside in Late February and set them out in Late April / early May and see what happens.

Also, based on what I know of your zone I would only be putting plants and maybe sets in around late April / early May since seed would want to have been started at least a couple of months earlier indoors.

Thanks for the info! How many weeks does it take to grow transplants from seed? (Late Feb to Late April/early May would suggest 8-10 weeks?)

Makalu, can bulbing onions ever be direct seeded? Territorial Seed has some storage onion varieties that they list as direct seed. I also have a book that says bulbing onions can be direct seeded in mid-April in our zone. But I'm not sure why some onions are direct seed-able and others are not. Does it have to do with whether they are grown for storage or not?

Thanks,
gardenerzone4

Most onions can be direct seeded. The logistics are the problem. Onions have a long growing season and they need to come to maturity at the appropriate daylenght for bulbing. Direct seeding requires precision planting and good conditions for emergence. That is hard to control in the field. Starting plants under controlled conditions and tranplanting at the appropriate time alleviates much of the uncertainty.

I winter sowed some candy last year they were small when they dried down kinda like golf ball size maybe a little larger. I think they need to be started indoors in March to make large bulbs. My late February indoor seeded copra's got large. For scallions you can plant about any time by direct sowing.

Curt