Black Raspberry

Size, growth and what to expect

Black raspberry grows fast, about two feet a year in our growth estimator. It makes a clump of arching canes 3 to 6 feet tall and 4 to 8 feet across. The roots live for years, while each cane lives only two summers.

Clusters of small white flowers open from April into June. The berries ripen in June and July, purple-black and about half an inch across, and they lift off the core as a hollow cap. They taste sweet and slightly tart, with a rich flavor in the best plants. Wild turkeys, songbirds, deer, foxes, black bears, raccoons and squirrels eat them, and birds and small mammals pick the seeds from fallen fruit in winter.

It grows wild from New Brunswick and Maine west to the Dakotas and Colorado, and south to Georgia, Mississippi and Oklahoma. It lives in open woods and woods edges, on bluffs and stream banks, and in old fields, pastures, fencerows and roadsides.

How to grow Black Raspberry

Black raspberry fruits best in full sun and grows in part shade, though its canes will not fruit in deep shade. It wants a moist, well-drained soil rich in organic matter, and it takes limy ground. Standing water can kill the roots. Its canes arch over and root where their tips touch the soil, so a planting creeps outward into a thicket unless the canes are tied up. Keep it away from a patch of garden raspberries or blackberries, since wild brambles nearby can bring diseases into the patch. Set plants 4 feet apart, and keep each one 4 feet from a wall. It is small enough to stand within 15 feet of overhead wires.

Saplings ship bare-root or potted. Plant them in early spring while they are still dormant, in a hole wide enough to spread the roots and at the depth they grew. Put the native soil back in, firm it gently, and keep the mulch clear of the canes. Sow the cleaned seed outdoors in late summer or early fall, an eighth of an inch deep. For spring, hold the seed damp in the refrigerator for 60 to 120 days first. Seedlings come up in spring, some not until the second or third. Most plants are raised from tip layers or divisions, since seed is slow and uneven to sprout. Seed-grown plants vary in the size and flavor of their berries, and none comes true to a named garden variety.

Water weekly from flowering until the harvest, since the roots lie shallow. Rabbits eat the canes in winter, so circle young plants with chicken wire. When new canes reach about 2 feet, pinch out their tips so they branch. After the harvest, cut the canes that fruited to the ground. In early spring, keep four or five strong canes per plant, shorten their side branches to 12 to 18 inches, and tie them to a support.

Each flower carries both male and female parts, so there are no male and female plants to pair. Bumblebees, honeybees and other wild bees carry the pollen, and the more bees at work, the more berries. Each cane bears in its second summer and then dies, so a seedling first fruits in its second year. Honey fungus and cane borers are its main troubles, and spotted wing drosophila can spoil the ripe berries.