Allotment Growing

Growing & Using Comfrey for Gardeners

Comfrey The Wonder Plant - Your Own Compost Mine

• Medicinal use of comfrey
• Nutritional Value of Bocking 14 Comfrey
• Allotment Uses of Comfrey
• Cultivation of Comfrey
• Obtaing Comfrey , Planting and the growing for the first year
• Harvesting and Propagating Comfrey
• Making Comfrey Liquid Compost or Comfrey Tea
• Further Information on Comfrey

Medicinal use of comfrey

Comfrey has long been known in Britain as a medicinal herb, its common name was ‘knitbone’. Supposed to assist in healing broken bones and skin complaints, many still use products from it for those purposes.

In the nineteenth century a Quaker smallholder, Henry Doubleday, became intrigued by the possibilities of Russian Comfrey as a useful crop. Leap forward to 1954 and Lawrence D Hills took up the cause. Almost as a side effect he started what has become Europe’s largest organic gardening association, the HDRA.

Comfrey contains high levels of the basic NPK nutrients, drawn up from the deep by its extensive root system. As such it can be useful as animal feed and as plant feed. The plant re-grows from small root cuttings and, as a weed, is very difficult to eradicate.

On the HDRA trial ground at Bocking in Essex, L D Hills developed the most valuable variety, Bocking 14. High in nutrients and sterile (you don’t want comfrey popping up all over the place) Bocking 14 is exclusively propagated from root cuttings.

Nutritional Value of Bocking 14 Comfrey.

L D Hills listed the following in his book Comfrey, Past Present and Future –

L D Hills did a more measured experiment of 14lbs of comfrey leaves in a 20 gallon drum (cited in Comfrey, Past Present and Future) and found the following results comparing with commercial liquid feeds made up to the manufacturer’s specifications.

Allotment Uses of Comfrey

• If you are able to keep chickens on your allotment you can feed wilted comfrey to them.
• As a compost activator - comfrey is so rich that it not only enriches your heaps but encourages them to heat up.
• The first cut of the year, in spring, should go in to the furrow before the potatoes. The liquid feed will also be good for potatoes as will chopped wilted leaves as a mulch - before the foliage gets too dense to effectively spread it.
• As a mulch and as a liquid feed for tomatoes, runner and dwarf beans.
• Mix with leafmould to make a base for potting compost.

Cultivation of Comfrey

Location and Preparation of your Comfrey Bed

Comfrey is a pretty tough plant that will grow from small pieces of root so do choose your location with care. It is easier to kill most weeds than comfrey. If you do need to move a comfrey bed the old bed will need to be killed off. Your best bet will be to use a weedkiller like ammonium sulphamate .

Comfrey will thrive in full sun or in partial to near full shade - there is usually a disused corner that will make a great site for your comfrey bed. It doesn't like thin, chalky soils and the roots go down a fair way so dig deeply and break up the subsoil to get it off to a good start. Light sandy soils will benefit from organic matter. Being a fleshy plant it will need a lot of water and a soggy patch will be a plus.

Turn the soil over and remove any perennial weed roots. Comfrey grows very densely and will be difficult to weed. It does tend to shade out most weeds once established. If you have any manure - even poultry manure - fork this into the top 6 inches of the soil. Comfrey is great for soaking up nutrients and, unlike most plants, will not burn with raw manure.

Obtaining Comfrey , Planting and the growing for the first year.

You can obtain plants from The Organic Gardening Catalogue for most of the year but, if you can, plant in March, April, May or September for best results. I start the plants off in pots - just to get them off to a good start - and then plant out. You can plant directly but I like to ensure success, especially as they can cost over a pound each!

Block plant around 2 to 3 feet apart and stand back. You will be surprised how quickly they grow. When the flowers appear take a cut. I use a pair of shears and cut about 6 inches from the ground. Comfrey has little hairs on the leaves, which can irritate. Not quite a cactus but near, so wear gloves.

Come winter the plants go dormant and a good layer of manure can be applied.

Harvesting and Propagating Comfrey

In the second year your comfrey patch starts to really pay off. In the spring it will leap back from its winter sleep. Your first cut will get the spuds off to a good start. After that you should get at least a further 3 cuts - even 4.

To get further plants, push your spade through the middle of a plant and lever up a portion. Take root cuttings (about 2 inches long) and away you go again. Be careful as the bits left over will happily root wherever they fall.

Making Comfrey Liquid Compost or Comfrey Tea

Comfrey can be made into a wonderful liquid feed – it is quite simple. Take a barrel or tub, add comfrey leaves, fill with water and leave for 3 to 5 weeks. Warning! It will smell like an open sewer when finished. The liquid can be used as a tomato feed. I tried this with a tub with a tap but it was always getting blocked, but if you put the leaves into an old potato sack it solves this problem.

Further Information on Comfrey

I've put together a little booklet on comfrey, expanding on this article, which is available as a pdf document here

The best book on comfrey is undoubtedly Comfrey: Past Present and Future by Lawrence D Hills. It appears to be out of print but if you see a copy - grab it.

The Organic Gardening Catalogue has a selection of comfrey products and a booklet on how to grow and use comfrey.