Answer: Here is an excerpt from an article in National Gardening magazine. You can find the whole article at this web address: http://126.96.36.199/articledetails.taf?id=85&kwd=raspberri...
Brambles are grouped according to when they bear fruit:
Summerbearing brambles. Canes fruit only in the summer of
their second year.
A cane begins fruiting near its tip toward the end of its first
season, then in the summer of its second season the cane
finishes fruiting lower down. Because new canes grow from
ground level each year, both kinds always have both 1- and
2-year-old canes, so the patch fruits every year.
When and How to Prune Brambles
Prune Out Old Canes
The descriptions above offer clues to one step in the pruning
process. When canes have finished bearing their summer
crop, or sometime before your bramble patch wakes up
again the following spring, cut to the ground any canes that
have completed their second growing season.
You will also need to thin out the patch, since the plants produce many new shoots each year. And remove any diseased or damaged canes. There are also techniqes to improve the quantity and quality of the harvest; these are discussed in detail in the article.
Hope this helps!
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