Blackberries and Raspberries
Blackberries and raspberries are vigorous plants that have aspirations to take over the world – or at least your garden – so growing them in a raised bed is a great way to minimize the problem. Blackberries can send out new shoots up 10 feet away from the mother plants. In most cases a lawn mower will keep them under control – as long as you catch them early and mow frequently. Almost all varieties are covered with sharp thorns, though there are a few thornless raspberries for the less intrepid.
Both of these brambles produce delicious and delicate fruit. Because the fruit doesn't travel well, it's usually quite expensive to purchase. All the more reason to grow your own berries.
Blackberries are available in upright, semi-upright and trailing varieties. The trailing ones are not as cold hardy as the others, and blackberries, in general, are less hardy than raspberries. Raspberries are available as summer-bearing and fall-bearing. Raspberries can be red, yellow, black or purple. An advantage of the fall-bearing raspberries is that they usually bear fruit after the departure of Japanese beetles, which sometime plague the summer-bearing varieties. But in colder zones you run the risk of losing the entire crop to an early frost.
Plant brambles in full sun and rich soil that retains moisture. They do best in a slightly acidic soil; pH 6 is ideal. Good air circulation is essential as mildew and mold can be a problem in hot, sticky summers. Prepare the planting area by eliminating all grasses and weeds. Weeding a bramble patch is no fun, so take the time to get rid of them before you plant. Next, work in 4″ to 6″of organic matter, such as compost or rotted manure, and add some granular organic fertilizer according to package directions. Plant the rooted cuttings approximately 2 to 3 feet apart in rows that are 2 feet wide. Wider rows make it extremely difficult to reach in and pick berries at the center of the bed.
Both blackberries and raspberries are biennials: they send up shoots ("canes") that produce leaves the first year and berries the second year. One the cane has fruited, it back to the ground. Prune out these spent canes in fall or late winter. Identifying spent canes is easy: the bark will be dull and the tops will show the remains of flowers or berries. Cut the dead canes right to the ground and drag them out of the patch. Using a long-handled pruner or loppers for this job means you can work without exposing yourself arms to the thorns. For a more detailed description, read the article Pruning Raspberries.
Vigorous varieties of blackberries and raspberries should be encircled with one or more strands of wire attached to posts or poles. This will both contain and support the branches, allowing for easier picking and a neater-looking berry patch.
Raspberry and blackberry plants should produce 2 to 3 pints of berries per year.