Just like bow wood you can harvest it when you need it. I leave the bark on while some say it is easier if you strip it. either way you do it bundle the shoots up as straight as you can get them and let them dry. After they are dry you can strip them and straighten them. I like to steam them, for me it is easier to work, dry heat will also work, When they are fairly straight you can finish plane them. That is about all there is to it, they make some good shafts.
If you have some decent shoots you are lucky. I looked all turkey season and didn't find any shoots really straight enough to harvest. May be the weather, all the shoots were short and limby.