The Wonders of Comfrey
As I continue my journey deeper into veganic gardening, I am perpetually amazed at the wealth of resources present in our own backyard. It seems that anyone with a proper compost pile, a source of mulch or green manure, and common beneficial “weeds” scattered about has all the resources needed to help their garden thrive.
One of my new favorite herbs for the garden, or “weeds”, depending on your perspective, is comfrey (Symphytum officinale), which has a wealth of uses for both our own health and the health of the garden.
Comfrey’s deep roots work to bring nutrients up from the subsoil. These nutrients are then made available in the abundant number of leaves it produces every year (4-5 lbs of leaves per established plant per year). The leaves are rich in nitrogen and potassium with a decent amount of phosphorus as well, making them a wonderful homegrown fertilizer. Researchers in British Columbia analyzed the NPK (nitrogen-phosphorus-potassium) ratio of comfrey and discovered that the leaves have a remarkable NPK ratio of 1.80-0.50-5.30.
Next: NPK of animal manures
When we compare these nutrient ratios (1.80-0.50-5.30) to that of animal manure, we can see how far superior comfrey* is.
Dairy Cow: .25-.15-.25
Note: Naturally, nutrient values of animal- or plant-based manure can vary greatly from specimen to specimen.
As you can see from this list, the nitrogen content of comfrey is higher than almost all animal manures found on the market today and its potassium concentration is far superior to all, making it an ideal fertilizer for plants that produce flowers, seeds and fruit for which potassium is an essential component. This, along with the more important ethical and environmental incentives for not using animal inputs in our gardens, makes growing comfrey as a fertilizer a win-win.
If you don’t think the NPK ratio of the dried leaves is impressive enough, you can also make a concentrated liquid fertilizer out of comfrey (see my next post on uses for comfrey in the garden) with an NPK ratio of about 8-2.60-20.50! (You’ll want to dilute this before use.) The leaves are also full of silica, calcium, iron, magnesium and other essential nutrients to help your fruiting plants thrive.
* Air-dried powdered comfrey leaf tissues.
Next: Health Benefits of Comfrey
Health Benefits of Comfrey:
Comfrey is also called knitbone, knitback, consound, blackwort, Ass Ear, Slippery Root, boneset, yalluc (Saxon), gum plant, consolida and bruisewort.
From the pattern of these names, you’ve probably guessed that comfrey can do more than benefit your garden. It also has powerful healing properties, supporting the body’s ability to repair damaged tissue and bones.
Comfrey roots and leaves contain a substance called allantoin, which, along with other beneficial compounds in the plant, supports healthy cell growth and reduces inflammation. Comfrey has been used externally as a poultice or ointment to heal bruises, broken bones, closed wounds, pulled muscles and ligaments, fractures, as well as reducing inflammation from sprains and more.
There is some controversy over comfrey though, because it also contains poisonous substances called pyrrolizidine alkaloids that have been shown to be toxic to the liver when ingested. For this reason, oral comfrey products have been banned in many countries, including the U.S. It is reported that some of the pyrrolizidine alkaloids can be absorbed through the skin as well, but there are varying opinions as to the actual risk of poisoning through topical use. It is best to find a knowledgeable herbalist or naturopath who can teach you the correct way to use this wonderful herb. Most recommend using comfrey externally, for no more than 10 days at a time and no more than 4-6 weeks out of the year. While many feel that caution with this herb is important, it is also a powerful healing tool if used correctly.
So now that you know all about this wonderful herb, weed, and garden companion, get out there and get growing!*
*Make sure you know more about how comfrey grows before planting it: it is a sturdy plant and will thrive in most soil. Because of these factors, it can be difficult to get rid of if you decide to remove the plant. For more information on this, check out my next post.