Comfrey Plant Profile

Why Plant Comfrey?

Comfrey, Symphytum officinale

It is one of the top 10 plants species for nectar – great for bees!

Provides more potassium, potash and nitrogen to the soil than organic fertilizers

Comfrey leaves make great compost either added to the compost pile or applied around plants in the garden

'Comfrey tea', like compost tea, can be used as a liquid feed

History Of Comfrey

By 400 B.C. this plant was already in use in Greece. The earliest recorded Comfrey remedies were made only of the root. The Greeks used to staunch severe bleeding and later to cure bronchial problems. To this day it is well-known as a natural healer for healing wounds, broken bones, as well as respiratory and gastrointestinal problems.

Comfrey is native to Europe and Asia. Although comfrey has been used as a food crop, and as a forage crop, in the past 20 years scientific studies reported that comfrey may be carcinogenic, since it appeared to cause liver damage and cancerous tumors in rats. Comfrey-pepsin capsules, which are sold as a digestive aid in herbal and health-food stores in the US, have been analyzed and found to contain pyrrolizidine alkaloids. These alkaloids can cause liver damage in people and are a potential carcinogen

The genus name of Comfrey, Symphytum, is derived from the Greek, “to make grow together,” It was the official medicinal plant sold in apothecaries. The common name, Comfrey, comes from the Latin 'con firma', alluding to the uniting of bones. The other common names given to this plant allude to its healing powers: boneset, bruisewort, and knitbone.

Wild comfrey was brought to America by English immigrants for medicinal uses. The allantoin content of comfrey, especially in the root, has resulted in its use in folk medicine for healing wounds, sores, urns, swollen tissue, and broken bones. Allantoin, found in milk of nursing mothers and the fetal allantois, appeared to affect the rate of cell multiplication. Wounds and burns seemed to heal faster when allantoin was applied due to a possible increase in number of white blood cells. Comfrey has been reported to promote healthy skin with its mucilage content that moisturizes and soothes, while the allantoin promotes cell proliferation.

Botanical Name: Symphytum officinale (most popular)
Plant Type: Herbaceous perennial
Mature Size: 1 to 3 feet, similar spread
Sun Exposure: Full Sun, Part Shade
Soil Type: Medium moisture, rich well-drained soil
Bloom Time: Late spring
Flower Color: Violet, Pink, Creamy Yellow
Hardiness Zones 3, 4, 5
Native Area: Europe, Asia

How To Grow Comfrey

Comfrey is easily grown in average, medium moisture, well-drained soils in full sun to part shade. Best grown in moist, organically rich soils, but has respectable drought tolerance and will perform reasonably well in somewhat dry locations. Comfrey is easily propagated by seed, root cuttings or division. When grown from seed, plant the seed 1/4-inch deep directly in the garden about 3 weeks before last spring frost. Cutting back stems promptly after flowering may encourage a rebloom.

As with all rapid growers, comfrey needs a lot of nitrogen. Comfrey gets all its nitrogen from the soil, so some regular organic matter is essential. Once comfrey is established it will take care of itself with little attention. Each year the plant will get a little larger, and the root system will get denser. Comfrey can live several decades before it begins to decline.

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.

Comfrey Cultivars

Creeping comfrey, Symphytum grandiflorum, is also known as dwarf comfrey and as its name suggests, it will creep through the whole space that you plant it in. Therefore only plant it if this is what you want. It’s also been described as ornamental comfrey. This is the comfrey that will quickly become a “weed” in your garden, so be careful where you place it.

Russian comfrey, Symphytum x uplandicum, is the most popular type of comfrey for the grower, it’s a hybrid of Symphytum officinale (common comfrey) and Symphytum asperum (rough comfrey). There are two main cultivars used, Bocking 14 and Bocking 4, named after the place they were developed, Bocking in the UK.

Prickly Comfrey, Symphytum asperum, is a coarse, hairy, rhizomatous perennial that is typically grown in shaded wildflower areas or naturalized areas for its attractive foliage and spring flowers. It grows to 3-4' tall. This plant has been found to be weedy and potentially invasive and should not be planted in Midwestern gardens.

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