Symphytum officinale
Common Name: comfrey
Type: Herbaceous perennial
Family: Boraginaceae
Native Range: Europe, Asia
Zone: 4 to 8
Height: 1.00 to 3.00 feet
Spread: 0.75 to 2.50 feet
Bloom Time: May to June
Bloom Description: White to pink to purple
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Suggested Use: Naturalize
Flower: Showy
Tolerate: Deer, Drought, Clay Soil

Culture

Easily grown in average, medium moisture, well-drained soils in full sun to part shade. Appreciates some afternoon shade in hot summer climates. Best in moist, organically rich soils, but has respectable drought tolerance and will perform reasonably well in somewhat dry locations. Once planted, comfrey can be very difficult to dig out because any small section of root left behind can sprout a new plant. Planting in large containers may help restrain its spread. Easily propagated by seed, root cuttings or division. When grown from seed, plant the seed 1/4” deep directly in the garden about 3 weeks before last spring frost. Cutting back stems promptly after flowering may encourage a rebloom.

Noteworthy Characteristics

Symphytum officinale, commonly called comfrey, is a large, coarse, tuberous-rooted, clumping perennial (to 3’ tall and 2.5’ wide) that is primarily grown today as an ornamental for its attractive foliage and spring flowers. Large, pointed, hairy, ovate-lanceolate, dark green basal leaves grow to 8” long. Upper leaves are decurrent and much smaller than the basal ones. Mature stems are winged. Tubular, bluebell-like, white to pink to purple flowers appear in drooping clusters (scorpiod cymes) in mid-spring to early summer. Comfrey (also commonly called knitbone or boneset) has been cultivated since 400 B. C. as a healing herb. Immigrants first brought the plant to America in the 1600s for medicinal use. Over time, comfrey has naturalized along roadsides and in waste areas throughout much of the U.S.

Leaves and roots have been used for many years in poultices for treating a variety of external inflammations, rashes, swellings, cuts, bruises, sprains or broken bones. Internally, comfrey has been used to treat a number of other medical problems including ulcers and colitis. Young leaves and stems were once cooked as a vegetable (like spinach). Leaves were also once used for herbal teas. Although some controversy still exists regarding internal use, plants are now generally considered by most experts to be unsafe and dangerous for ingestion.

Genus name comes from the Greek words symphyo meaning to grow together and phyton for plant as the plant was believed to help heal wounds.

Specific epithet means sold in shops and was often applied to plants with supposed medicinal properties.

Common name of comfrey reportedly comes from con firma (Latin meaning with strength) in reference to its reputation for healing wounds and broken bones (leaves and roots contain allantoin).

Problems

No serious insect or disease problems. Slugs and snails may attack the foliage. Plant foliage may flop after strong rains.

Garden Uses

Herb gardens. Naturalize in woodland gardens, open shade gardens, cottage gardens or wildflower gardens/meadows where plants can form attractive colonies over time. Also may be grown in large containers. Leaves are good for compost. Many consider this plant too coarse for use in borders.