Comfrey

Comfrey is one of the most useful plants you can grow in the garden or on your allotment. It has a range  from natural medicine through being a wonderful fertiliser to being an animal feedstuff.

The History of  Comfrey.

Comfrey is a native herb in Britain and has long been known as a medicinal herb. It was cultivated by both Greek and the Romans. It's botanical name is Symphytum officinale and it is a member of the Boraginaceae family as are Borage and Forget-me-not. The name Comfrey is a corruption of 'con firma', which ties in with its comman name of Knitbone. The botanical name, Symphytum, is from the Greek symphyo meaning 'to unite'.

Nutritional Values Of Comfrey

Comfrey contains high levels of the basic NPK nutients, drawn up from the deep by its extensive root system. This NPK mix makes it an ideal fertiliser for many vegetables but especially so for potatoes and tomatoes. On the HDRA trial ground at Bocking in Essex, LD Hills developed the most valuable variety, Bocking 14. High in nutrients and sterile, Bocking 14 is exclusively propogated from root cuttings.

Nutritional Value of Bocking 14 Comfrey

Material       Water %      Nitrogen % (N)     Phosphorus % (P)      Potash % (K)     Carbon-Nitrogen Ratio

Manure           76.00                 0.64                           0.23                            0.32                       14:1

Comfrey          75.00                0.74                           0.24                             1.19                       9.8:1

Compost          76.00                0.50                           0.27                             0.81                       10:1

Comfrey Liquid Feeds

Comfrey can be made into a wonderful liquid feed, it is very simple. Take a barrel or tub, add comfrey leaves to about a quarter way up, fill with water and leave for about 3 to 5 weeks. It will smell like an open sewer as it ferments!!!

Another way is to fill a hesian sack full of leaves and leave it soaking in the water (like a T bag). The liquid can be used as a feed to the garden. Sprinkle the liquid using a watering can.

Over a season you can expect to get three or four cuts from an established comfrey bed. The first cut is probably the best used under potatoes. A layer of, preferably, wilted leaves placed in the trench under the potatoes will quickly rot down to provide nutrition to the potato crop. For best results you need between 1lb and 2lb of comfrey per foot of row. The second cut can be used to start making liquid feed, this is especially benificial for tomatoes, French and Runner Beans.

The high level of nitrogen in comfrey and the low carbon/nitrogen ratio makes it an ideal activator for the general compost heat. Mixing comfrey with compost and leaf mould will create a natural compost, ideal for potting on tomatoes or growing potatoes in bags organically.

Cultivation of Comfrey

Comfrey is a pretty tough plant that will grow from small pieces of root so be careful where you plant it and not to drop any off cuts. If you need to move a comfrey bed the old one will need to be killed off with a weed killer. It will thrive in full sun, partial shade or near full shade. It doesn't like thin chalky soils as the roots go down quite a long way so dig it in 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. In the wild comfrey tends to be found in shaded boggy areas such as river banks. Turn the soil over and remove any perenial weed roots. Once established it will shade out most weeds.

Plant in March-May or September for best results. The plants are started off from root cuttings, from the crown or lower down. Start them off in 3" pots in a cold frame and then plant them out. Use a general purpose potting compost and plant just below the surface, unless there are some shoots showing, in which case just plant to the shoots. You can plant out directly but potting up increases success.

Once the shoots have appeared, and it is obvious the plant is growing, they need to be moved into the bed. The roots grow very quickly. Plant about 2 to 3 feet apart and stand back and see them grow. Fairly quickly the plants will produce flower stalks as well as foliage. Its best to prick these stalks out saving wasted energy going to produce streile seeds. Add them to the compost bin. From Spring plantings you should be able to take a cut in mid to late Summer. Cut to about 6 inches from the ground. Comfrey has little hairs on the leaves, which can irritate, so wear gloves.

Manure can be applied between plants after each cut. Come Winter the plants go dormant when some lime can be added. Because of the high level of acid fertiliser, liming annually may be required to keep the soil sweet.

It is the second year when your comfrey patch starts to really pay off. In Spring it will leap back from its sleep and you can take your first cuttings to get your potatoes off to a good start. After that you should get at least 3-4 more cuts. Splitting is easy, just dig your spade through the middle of the plant and lever up a portion. Be careful as any bits of root dropped will happily grow wherever it falls.