When do you plant Brussel Sprouts?

I'm new to zone 5 and we planted them last spring. (Started them in the basement)
I guess it was summer by the time they grew big enough to produce and perhaps then it was too hot for them.
Now after months I finally got some sprouts big enough to harvest.

So are they a cold weather crop?
Do you plant them in the summer for a fall crop?
Do you plant them late winter for a spring crop?

The few I got were delish, but it's snowing today and I'm sure too cold for the plant to survive much longer.

What is the secret to growing lots of lovely brussel sprouts?
Dove

Dovey - You may want to try posting on the Beginner Vegetables Forum, someone there may be able to help! Samantha

Thanks Graceful,
I'll track down that forum and repost there