I have not tried to grow Cippollini onions. It is a long day onion which means it need long daylight hours to bulb. I would think that you would plant seed in January or February. You coul probably plant them now, but you would gain much as they want begin bulbing until June. Onions are asy to start from seed so you should have no problems on that score. In your zone and you like onions , you might want also try short day onions planted now, bulb up in March, harvest in May.
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