Leafing through the pages of comfrey controversy.
Comfrey uses and benefits are many, varied and somewhat conflicted. A quick superficial search indicates that comfrey is dangerous and toxic. However, that’s rooted in incomplete information perpetuated without qualification and clarification.
Yes, comfrey uses include medicinal—both internally and externally—and yes, comfrey has been found to be toxic when taken internally. So how to be safe? Educate yourself and use common sense.
We’re beginning this journey with you here. We will also link to reliable sources where you can continue your education, should you wish to go deeper.
“We all learn at the humble roots of the plants…all the way back to the beginning of time. Let’s not forget how to listen, how to hear, their language. It is not a lost language, or languages as they speak in many tongues, but a forgotten language that is heard with the heart.”
~Rosemary Gladstar, herbalist, author
The Incredible Comfrey
Common Names for Comfrey
- Black wort
- Ass ear
- Wall wort,
- Sippery root
- Gum plant
- Healing herb
- Knit back
Comfrey is one of the most beneficial plants and weeds you can use for compost tea. In fact, our plants love comfrey compost tea, and it’s one of our favorites, especially since we have so much of it flourishing. We’re all in favor of some of the best fertilizer ever… for free!
Comfrey is an amazing plant but unless you get the Russian variety, it can take over your garden! We didn’t know that when we first planted ours, but now that we use it regularly to nourish our garden, it all works out.
We have plenty for nutritional and medicinal use for ourselves as well as our garden compost and compost tea, plus enough to give away. At first we were bummed that we did not get the non-invasive Russian comfrey, but now we’re glad because the common comfrey one we’re growing can also be used medicinally as well as for organic fertilizer for plants.
Comfrey is an amazing plant whose roots can grow as deep as 20-30 feet! Comfrey’s incredible root system is the reason it has so many nutritional and medicinal benefits for plants and humans.
- Mineral rich
- Grows easily
- Frost resistant
- Prefers full sun
- Drought resistant
- Thick furry leaves
- Dubbed ‘a miracle herb’
- Very deep roots (20-30 feet)
- One of few plants containing vitamin B12
- Some varieties can be very prolific (invasive)
Comfrey’s deep roots and big leaves means deep mining for—and storage of—minerals and trace nutrients.
Comfrey for Plants – Symphytum x uplandicum
The best comfrey for your garden is Russian comfrey, Symphytum x uplandicum. This non-spreading form of comfrey is superfood for your plants, but not for your body.1)https://www.henriettes-herb.com/faqs/medi-2-15-comfrey.html
Comfrey Uses in the Garden
- A green fertilizer – you can place chopped leaves in your compost or around your plants
- Compost activator – as a liquid fertilizer ‘comfrey tea’
- Water soluble fertilizer – delivers nutrients more evenly and avoids chemical burn2)https://www.extension.purdue.edu/extmedia/ho/ho-251-w.pdf
- Anti-fungal – Contains copper, beneficial as an anti-fungal and anti-viral plant spray
Comfrey Compost Tea Recipe
- Fill container ~3/4 full with chopped or torn large comfrey leaves (we use a 5 gallon bucket)
- Add water to the top
- Steep for ~2 weeks until leaves rot (we cover ours loosely with a board)
After leaves are rotted:
- Stir, then pour half into another bucket
- Add water to both buckets until mix is a weak tea color, (you now have double the amount)
- Pour around the roots of your plants, (we pour from the 5 gal. into a garden watering can with the “rose” spout removed.
Start a new batch.
Once this batch is ready, go ahead and start your next batch to steep for two weeks. That way you will have enough to water your plants every week or two with compost tea, and watch your plants thrive! If you have a large garden and lots of plants, then double your quantity and/or frequency.
We’ve written more and included videos on making compost tea in another article you may enjoy.
While visiting one of our favorite growers, Edible Landscaping, in Virginia, we enjoyed a tour by EL manager, George Dean. George has worked with plants all his life, including for the Reagan Whitehouse greenhouse.
We thoroughly enjoyed his tour expounding on the many benefits of comfrey, amongst many other plants. Here’s his take.
If the video is not showing below, it’s due to some technical difficulties on our site this morning, but you can copy and paste this link into Google or YouTube and it should come up.
Comfrey Compost Tea Recipe – SIMPLE Old Timey
Less smelly, this time-tested process is even simpler. You’ll just need to buy or make a dispensing bucket with a spigot or tap at the bottom, or a top pump that siphons it from the bottom.
- Fill a container with chopped comfrey leaves
- Place lid or weight (we use a couple bricks on top of plywood cutout)
- The lid doesn’t need to be tight but you’ll want to keep it out of the rain
- NO WATER
The leaves should break down in a couple weeks but without the unpleasantly potent odor resembling dead fish. In a couple weeks or so, you’ll have a black fermented comfrey tea concentrate.
- Dilute 1 part comfrey concentrate to 20 parts water for container plants and seedlings
- Dilute 1 part comfrey concentrate to 10 parts water for garden and larger plants
If you have any extra, store in a jar in a cool dark place or refrigerator. Just be sure to mark it as COMFREY for the GARDEN so that no one mistakes it for human food!
Dangers of Comfrey
Illness and even death has occurred from uneducated use of medicinal plants such as comfrey.
Dangerous Lookalike Plants
The leaves of comfrey resemble those of foxglove (Digitalis purpurea), so this mistaken identity is even more likely to occur when the plants are not in bloom.3)https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/comfrey
Cardiac glycoside poisoning4)https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/glycoside can occur when people confuse foxglove (Digitalis purpurea) for the comfrey plant, (Symphytum officinale).
Most of the toxic issues involving plants and herbs in health and healing, including comfrey, is mostly a matter of absence of knowledge. Fatal cases involving comfrey typically includes excessive use or use by people with existing conditions or proclivities.5)https://www.henriettes-herb.com/faqs/medi-2-15-comfrey.html
People tend to forget that plants—especially herbs—contain high concentrations of medicinal substances. As such, it’s best to take doses and remedies in quantities and preparations recommended by health professionals and herbalists with deep knowledge of this.
Safe Substitutes for Comfrey
- Calendula – wounds
- Plantago – wounds, coughs
~Henriette Kress, herbalist in Helsinki, Finland
Comfrey Uses for People
“Wild common comfrey, Symphytum officinale, has been cultivated since about 400 BC as a healing herb.“
The comfrey used for medicinal use is the common comfrey, Symphytum officinale. Symphytum is Latin meaning ‘growing together of bones (Greek ‘symphis’), and phyton for plant.
Remember, “medicinal”, means taken carefully, judiciously and under guidance. Informed and limited consumption and application of common comfrey has been used for millennia.
Healing Uses of Comfrey
- Wounds and burns seemed to heal faster (allantoin)
- swollen tissue
- broken bones
- Healthy skin – mucilage content
- regenerates – increase in cell multiplication (allantoin)
REMEMBER: Always use caution and guidance in using this or any medicinal herb.
Wishing you great gardens and happy harvests!
G. Coleman Alderson is an entrepreneur, land manager, investor, gardener, and author of the novel, Mountain Whispers: Days Without Sun. Coleman holds an MS from Penn State where his thesis centered on horticulture, park planning, design, and maintenance. He’s a member of the Phi Kappa Phi Honor Society and a licensed building contractor for 27 years. “But nothing surpasses my 40 years of lessons from the field and garden. And in the garden, as in life, it’s always interesting because those lessons never end!” Coleman Alderson
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