Planting and Care
Plant red and yellow raspberries 2 feet (60 cm) apart in a row, and they'll fill in solid in a year or two. Space black and purple raspberries 3 feet (90 cm) apart. Keep the row width fairly narrow—6-24 inches (15 to 60 cm) wide—to allow every cane to get plenty of sun and be fully productive. Mow or till along the edge of the row as needed to keep the raspberries from creeping out.
Apply compost and a little balanced organic fertilizer in late winter, if needed, for good growth. Mulch to discourage weeds and keep the soil evenly moist; water during dry spells. Propogate by division or layering, but only if you are sure your plants are healthy. In many cases, you're best off buying new, certified disease-free plants.
Pruning and Training
Regular pruning will encourage your plants to produce high yields of top-quality berries. For a single fall crop on ever-bearers, simply cut off all the old canes at ground level when they are done fruiting.
Summer-bearing red raspberries produce fruit on 2-year-old-canes. Cut down the old, grayish brown fruit-producing canes after you harvest, but leave the new, current-season canes to produce berries next year.
In late winter, remove the smallest canes to leave three to six sturdy canes per 1 foot (30 cm) of row.
Black and purple raspberries produce fruit on side branches that grow off the older canes. During summer, cut off the fruit-producing canes after your harvest, and snip off the tips of new canes when they're 3 to 4 feet (0.9 to 1.2 m) tall to make them branch. During the dormant season, remove the smallest canes to leave four to six sturdy canes per 1 foot (30 cm) of row. On the remaining canes, cut out any spindly side branches and trim the remaining side branches back to 8 to 10 inches (20 to 25 cm) long.