There are two types of raspberries, June-bearing and ever-bearing.  June bearing raspberries produce a heavy crop of berries from June through early July.  Ever-bearing produce two crops, one in June and one in the fall (September through the first frost).  Prune June-bearing canes every spring.  The fruit is born on two year old wood, and after it bears a crop it dies.  In spring, wait until you see some green growth on the canes and then remove all the dead gray and brittle wood, cutting it at the base.  This year’s fruit is produced on those canes.  Prune ever-bearing raspberries in two methods. If a large fall crop is desired and no summer crop, all of the canes are mowed back 2 to 4 inches in the spring.  To crop the plants two times per year, prune them as June-bearing by removing the dead canes in the spring and cutting back the remaining live canes to about 5 feet tall.