Grapevines pose the greatest challenge. Depending on which pruning book you read the author usually spells out a convoluted formula that has the gardener reeling in confusion. I prefer what I call the Rule of Fours. If you can remember the number four, you can prune your grapes. As an older gardener, I find I have trouble remembering how many buds I'm supposed to leave, how many branches. Was it fifteen buds and four branches or the other way around? Arggggh! I've found this easy method of fours solves the problem, and my grapes don't seem to know the difference. Last year I filled a five-gallon pail with grapes off of just one vine.
Take off all but 4 of the major branches, two on each side of the trunk. Cut these 4 so that they are no more than 4 feet long. Leave 4 side shoots on each arm and cut them back to 4 buds. Take out any dead wood. You may prune the 4 major branches to be shorter or longer than 4 feet, depending on your space. Just remember that grapes won't produce very well unless they are pruned back hard.
Grapes should be pruned in late winter/early spring just as the buds are beginning to swell. Here in New Hampshire I prune my grapevines in late March. As with all pruning, cut branches close. Don't leave stubs, and cut at a slight angle.
Bramble fruits benefit from dormant pruning. You need to take out the previous year's fruiting canes. Red raspberries and blackberries bear on one-year-old canes. Two-year-old canes are brown and woody, making it easy to identify and remove them. Thin the canes to 4 per foot of row. The rule of fours again.
You can lop back the tops of your raspberries, though most pruning guides don't recommend it. I have to whack mine back. I'm too short to reach them otherwise. I cut one-year-old canes to just slightly higher than my reach. Blackberries and black raspberries can be top pruned to keep them under control.
Black and purple raspberries need more severe pruning. Take out all but four of the major canes. Chop them off at four feet high. Prune back the laterals to one foot long. If you don't cut the tops off black raspberries they grow long enough in a single season to touch the ground. The tips freely root, making for some strange looking canes, rooted at both ends. Though the kids might find this fun, it's not good for the berries. Summer prune long shoots to keep the planting from becoming overgrown.
