Why I Use Comfrey in My Forest Garden

And how I increase my stock of it on an annual basis.

blue comfrey

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Comfrey has almost become a cliché in permaculture circles. Many sustainable gardeners in temperate climates will already be familiar with this plant. Today I thought I would share with readers exactly why I use comfrey in my forest garden, and how I increase my stocks of this useful plant easily and quickly at this time of the year.

What Is Comfrey?

Comfrey (Symphytum officinale or its hybrid with Symphytum asperum that's known as Symphytum x uplandicum) is a perennial plant found in Europe, Asia, and North America. The most common type of comfrey used in gardens, and the comfrey I grow, is Symphytum x uplandicum (Russian comfrey) "Bocking 14"—a sterile cultivar developed in the 1950s by Lawrence Hills, founder of the Henry Doubleday Research Association. 

Comfrey is used commonly in permaculture design because it is:

  • A dynamic accumulator with very deep roots.
  • Quick growing—generating large amounts of organic material fairly quickly.
  • Resilient and suited to a range of different sites and environmental conditions. 
  • Good for grass and weed suppression. 
  • A great pollinator plant, attracting bees and a range of other beneficial insects. 
  • A good forage or feed supplement for chickens and other livestock. 
  • Useful in herbal medicine.

How I Use Comfrey in Garden Design

I use comfrey in a range of ways in garden design. It is important to remember that comfrey has deep roots and these plants are difficult, if not impossible, to eradicate from an area once planted. So you should choose carefully where these plants are positioned. I usually recommend the use of a sterile variety, so that the plants will not set seed and spread uncontrollably.

Due to the many benefits of these plants, comfrey can be extremely useful in a range of situations. Comfrey is an excellent choice for fruit tree guilds in a forest garden. It can be useful in lining paths and in preventing grass or perennial weeds from encroaching into growing areas. And it can be useful planted close to annual food-producing areas, where it becomes a bank of organic matter to improve and maintain fertility, as well as attract pollinators and other beneficial insects to the area.

How I Use Comfrey in Maintaining Fertility

Comfrey is not only useful while in active growth. I cut comfrey twice a year and use the material to maintain fertility in other parts of my garden. I chop and drop comfrey in the forest garden, and also use comfrey leaves as a potassium-rich mulch around annual plants—like tomatoes in my polytunnel, for example.

I add comfrey plants to water and leave them to "brew," making a stinky but effective liquid plant feed which I also use in annual food production.

Propagating Comfrey By Division

In autumn I turn my attention to propagating my existing comfrey plants to make new plants. Many perennial plants can be propagated by division. You simply split existing plants in half and get new plants to place elsewhere. Comfrey is, I find, one of the easiest perennials to propagate in this way. 

"Bocking 14" is, as mentioned above, a sterile cultivar that will not set seed; but by dividing the crown of the plant, each one can be used to make many more plants. Cut down through the center of the clump with a spade to split off a section. The section you remove can also be divided many times to make a huge number of smaller crown and root offsets. Even a small section of root just a few centimeters long will successfully grow into a new comfrey plant.

Comfrey is a very hardy plant, and I find that new divisions are quick to establish when planted elsewhere in the garden. So, increasing your plant stock really could not be easier.

Offsets (aka root divisions or side shoots) can be purchased easily online, but don't purchase too many, since over time you will find it very easy to generate many more comfrey plants to benefit your garden from your original purchase of just a small number of plants.

I purchased just four small offsets initially, and now have 20 or more comfrey plants growing in various places around my property. Comfrey may be a bit of a cliché, but it really is one of the easiest and most rewarding permaculture plants to grow.