In my climate we get shoots from tropical bamboos (clumpers) starting
in mid to late summer and then they continue to grow through winter and
into spring. The warmer the winter the faster they will grow, if it
gets too cold your shoots will stop growing for a while and then pick
up in the spring, if you are unlucky you'll have some aborted shoots.

Temperate bamboos (runners) shoot in spring and then will sometimes put
up another round of smaller shoots towards the end of summer. These
shoots grow fast and are completely hardend and leafed out by early
summer.

Chris
Chino, CA (USA)