Purple-flowering Raspberry

Size, growth and what to expect

Purple-flowering raspberry grows at a medium pace, about a foot a year in our growth estimator. Its thornless canes stand 3 to 6 feet tall, and a patch spreads 6 to 12 feet across. The bark of older canes peels, and the young stems bristle with dark purple, gland-tipped hairs. Its simple, maple-like leaves run 4 to 10 inches across and turn pale yellow in fall.

Fragrant rose-purple flowers about 2 inches across open from June to August, a few at a time over a long season. Songbirds, game birds and mammals eat the berries.

It grows wild from southern Quebec and Maine west to Michigan and south through the mountains to Georgia and Alabama, with outposts in northern Illinois. Its home is moist, shady woods and woods edges, rocky slopes, wooded talus and stream banks.

How to grow Purple-flowering Raspberry

Purple-flowering raspberry grows in part shade, sun or shade, and in part shade its flowers last longer. It wants a moist, well-drained soil rich in organic matter, and it dislikes clay, soggy ground and hot, humid summers. It spreads by underground stems into a thicket, so give it room or pull the strays. Set plants 4 feet apart, and keep each one 6 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 a hole wider than the roots and no deeper. Set the crown at the soil line, put the native soil back in, 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 later springs. Plants are most often started from suckers, which dig up easily.

Water it every day for the first two weeks after planting, then every two to three days until week 12. After that, water weekly through the first two summers. Prune right after it fruits, and take out the old canes each winter. Every few years, dig up part of the patch and replant it more thinly.

Each flower carries both male and female parts, so there are no male and female plants to pair. Bumble bees, other native bees and honey bees visit the flowers, and native bees use the plant for nesting. Honey fungus, which troubles most brambles, is its one known problem. The flat red berries ripen from July to September, and they are edible but dry, crumbly and bland.