Well you needed to start growing them in spring and harvest time is roughly December to February. Not really sure what you are asking guest.

Like most members of the cabbage family, they like well-drained, neutral to slightly alkaline soil, at least 6 hours of direct sun a day, better full sun, regular watering in dry spells, and occasional feeding with organic plant foods. Although the plants need adequate nitrogen to bear well, chemical fertilizers can give the sprouts a strong, rank flavor from too much nitrogen. As Moon_grower says, plant out in spring, and don't expect sprouts until late fall at the earliest. They are supposed to taste better after some frost, but I wouldn't know about that personally, here in southern Arizona!

I'd never pick brussels sprouts until they had been frosted.

I don't really get a choice, here, as some years we don't get frost at all--they don't really taste bad. I have had them from higher elevations, though, and those definitely tasted better. Both beat the grocery store ones hollow.