Why Grow Comfrey?
If you want a simple way to improve your garden and your life, grow some comfrey!
Comfrey, also known as Symphytum officinale, is a hardy herb with many benefits for home gardeners. This plant can survive in Zone 3, and it’s resistant to pests and diseases.
This herb serves a multitude of purposes, including medicinal and ecological uses.
Dry skin? You can use this as a moisturizer. It’s got properties that help cells grow and heal wounds. And it’s great for soothing bug bites, minor cuts, and sore muscles or joints.
No time to make these remedies? Don’t worry, the plant is totally eco-friendly.
Planting it can help build up the soil. Comfrey burrows way down to grab nutrients such as potassium, magnesium, and calcium for its roots and leaves. Plus, bees and other beneficial insects love their blossoms.
Comfrey’s Plant Cycle and Description
Traditionally, people used comfrey to repair bones, which is why it got the nickname knitbone. This healing herb is a perennial that grows two to five feet tall and has bell-shaped purple, blue, or white flowers. It has long, tapered, and hairy, deep green leaves that are connected to hollow bristly stems. It can get as wide as three feet.
Choose the Right Comfrey Variety
Common comfrey and Russian comfrey are the two popular varieties. Symphytum officinale or common comfrey, can spread vigorously and have flowers that range from blue, and cream to purple. Symphytum uplandicum ‘Bocking 14’ is a sterile hybrid (from Russian comfrey) and is not invasive because it doesn’t self-seed.
Comfrey’s Healing History
Early Greek medicine touted the healing properties of the comfrey root, which were believed to promote the growth of new tissue. Following some experimentation, a Roman doctor noted that the boiling of comfrey resulted in a paste that could hold pieces of meat together. It was a common practice on the battlefield of that era to use it for creating makeshift casts.
In the first century, physician Dioscorides suggested comfrey tea for breathing and stomach problems. As time passed, doctors used comfrey roots for various ailments, such as menstrual problems, hemorrhoids, and gout. The 19th-century eclectic physicians recommended it for diarrhea, dysentery, and cough. However, by the 1990s, herbalists stopped recommending it internally.
Planting, Growing, and Harvesting Comfrey
We have naturalized this native European and Asian plant to North American regions. This plant species thrives in various wetland habitats.
For home and urban gardens, we can plant it in containers via seeds or root division in the spring or fall depending on the variety. They grow best in well-drained soil and they can tolerate full sun or partial shade.
Russian Comfrey and cultivated varieties rarely set seeds because these varieties are sterile. It grows best by root cuttings, crown divisions, or transplants. One inch of a root is all that it needs. Root cuttings will bud in 3-6 weeks while crown division has a faster budding time of 2 weeks.
We can plant this herb throughout the year (from April to September). But people consider spring as the optimal season for planting this herb. We recommend laying the cutting flat at a depth of 2-4 inches. Planting depth increases with cutting size. The recommended planting method for crowns and transplants is upright and at a depth of 2-3 inches. You can plant roots, crowns, and transplants 2-3 feet apart. The closer you plant them, the bigger they will grow.
Watering requirements for young plants differ from older plants. Young plants require frequent watering, while older plants are more drought-resistant. You want to keep a moderate soil moisture level.
Besides adequate water, your comfrey plant would benefit from regular nitrogen fertilization. Because competing plants impede the growth of young plants, it is important to remove weeds.
Summer is the best time to harvest the leaves, but it is best to wait until the second year after planting. You can harvest leaves every two weeks throughout the season. It is best to cut the leaves 2 inches above the ground.
And if you want to use the roots for medicinal purposes or to propagate it, then wait for fall to lift it or harvest from the side of the root system. Wash comfrey roots and cut them into slices to dry. You can grind the roots in a blender or grinder and store them in a sealed container.
Collage of comfrey growth from crown division May 2023 to July 2023
Comfrey’s Medicinal Uses
We can use comfrey’s leaves and roots for external therapeutic purposes. There is controversy regarding if it is edible because of the toxin it produced. However, the leaves can make medicinal tea for poultice or gargle.
Comfrey manufactured allantoin which protects the skin and promotes new skin. The FDA considers allantoin safe in concentrations up to 2%. Many over-the-counter products for rash and dry skin contain this ingredient. Commission E, the German FDA equivalent, has given approval for comfrey root powder to be used in treating minor wounds. According to two German studies, comfrey cream was found to provide more pain relief for knee arthritis than a placebo.
For minor wounds, wash the area with soap and water. Then apply dried powdered root on the wound. Or you can make a poultice from the powdered root in water and cover it with a clean bandage. For pain relief, you can use comfrey lotion, or powder root to any skin cream.
Comfrey’s Garden Uses
Comfrey has many beneficial uses in the garden. It is a versatile plant that can be used for compost, antifungal spray, transplant-boosting spray, mulch, and medicine for your garden.
It’s a microbiome nurturer. The blossoms definitely attract bees and other beneficial insects, who are searching for pollen and nectar. The tap roots push through dry and clay-heavy soil. If you cut off the top growth, the roots die back. As a result, the deeper roots in the soil decompose and nourish the microbiome.
Comfrey is a nutrient accumulator. It reaches deep into the soil to pull potassium, calcium, and magnesium into the roots and leaves. Mulching or composting the above-ground parts of comfrey releases these nutrients into the ecosystem.
It is also a biomass producer. We can use the leaves of stems during the growing season as compost in place or any other areas to cover infertility. You can plant comfrey around fruit trees and practice chop and drop mulching in order to encourage it to regrow. This leads to more available nutrients from the earth, which change it into biomass and topsoil.
Warning about Using Comfrey
Using comfrey leaves and roots internally is not advised. The reason for this is due to the presence of pyrrolizodine alkaloids (PA), a toxic chemical that can result in liver impairment when consumed in large quantities. The PA content alters depending on the plant’s parts and type. It is believed that the roots contain the highest levels. Despite PA being believed to be insoluble in water and thus absent in comfrey tea, it has been detected in the tea. Consequently, the American Herbal Product Association advises that comfrey products should only be labeled for external application.
Prior to using it externally, gardeners must ensure that it is not the deadly look-alike foxglove. Therefore, I highly recommend growing your own comfrey.
References
Balick, M. (2014). Rodale’s 21st-Century Herbal: A Practical Guide for Healthy Living Using Nature’s Most Powerful Plants (V. Mattern, Ed.). Rodale Books.
Castleman, M. (2009). The New Healing Herbs: The Essential Guide to More Than 125 of Nature’s Most Potent Herbal Remedies. Rodale.
Hemenway, T. (2009). Gaia’s Garden: A Guide to Home-Scale Permaculture, 2nd Edition. Chelsea Green Publishing.