Comfrey Bocking 14
Comfrey is one of the most useful plants you can grow in the garden or on your allotment. It has a range of uses from a 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 the Greeks 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 old common 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 nutrients, drawn up from the deep by its extensive root system. This NPK mix makes it an ideal fertilizer for many vegetables but especially so for potatoes and tomatoes. 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 –
Material |
Water
%
|
Nitrogen
%
(N)
|
Phosphorus
%
(P) |
Potash
%
(K) |
Carbon -
Nitrogen
Ratio |
Farm Yard Manure |
76.00 |
0.64 |
0.23 |
0.32 |
14:1 |
Wilted Russian Comfrey |
75.00 |
0.74 |
0.24 |
1.19 |
9.8:1 |
Indore 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 quite simple. Take a barrel or tub, add comfrey leaves to about a quarter way up the barrel, fill with water and leave for 3 to 5 weeks.
Warning! It will smell like an open sewer as it ferments!.
The liquid can be used as a tomato feed. I tried this with a tub with a tap but it was always getting blocked due to the stalks that take longer to rot down. Now I just dip the watering can in. You can make a very concentrated feed by cramming a container with leaves and placing a weight on top to compress the leaves. A small hole in the base allows the brown liquor to drip through into a jar or suchlike. You can then bottle this for later use.
Using Comfrey in the Garden / Allotment
Over the season you can expect to get three or four and sometimes five cuts from an established comfrey bed. The first cut is probably 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.
Trials conducted by the L D Hills at the HDRA have shown that comfrey provides increased yield in potatoes compared with manure, compost or ‘Growmore’ artificial fertiliser. For these results you need between 1lb and 2lb of comfrey per foot of row.
One side benefit is that the flavour of potatoes is supposed to be improved by using comfrey as a fertiliser – especially against chemical methods.
The second cut can be used to start making liquid feed as described previously. This is especially beneficial for tomatoes.
Tomatoes grown in the ground will benefit from a mulch of wilted comfrey, a slow release into the soil as the plants get away.
Ideally, a second barrel will enable more liquid feed to be fermenting as the first batch is being used. Just as with potatoes, trials have indicated an increase in yield and quality of French and runner beans when fertilised with comfrey.
The high level of nitrogen in comfrey and the low carbon / nitrogen ratio, means that it is not really suited to making compost on its own. It is, however, an ideal activator for the general compost heat.
Where chickens have been kept on a deep litter system, the addition of comfrey will assist rotting down of the valuable by-product and balance the nutritional value by adding the missing potash.
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
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 weed killer like Amicide.
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.
In the wild, comfrey tends to be found in shaded boggy areas such as woodland river banks.
Turn the soil over and remove any perennial weed roots. Comfrey grows very densely and will be difficult to weed on the plus side, 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.
Cultivation of Comfrey
Planting and the First Year.
There are a number of varieties of comfrey, both cultivated and wild. The most commonly available and best for the gardener is Bocking 14. Plant in March, April, May or September for best results. The plants are started off from root cuttings, which can be from the crown or from lower down the plant. Either way they will usually take.
Start the plants off in 3” pots in a cold frame - just to get them off to a good start - and then plant out. use general purpose potting compost and plant a little below the surface unless there are some shoots starting, in which case plant to the shoot. 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 move into the bed. The roots grow very quickly so speed is important. Block plants around 2 to 3 feet apart and stand back. You will be surprised how quickly they grow.
Fairly quickly the plants will produce flower stalks as well as foliage and in the first year we don’t want energy being wasted in producing sterile seeds. The flower stalks are cut down and added to the compost heap. From spring plantings, you should be able to take a cut in mid to late summer. Just take a pair of shears and cut about six inches from ground level. Comfrey has little hairs on the leaves, which can irritate. Not quite a cactus but near, so wear gloves.
Manure (even poultry droppings) can be applied between plants after each cut and any weeds hoed off. Come winter the plants go dormant and lime can be applied. Because of the high level of acidic fertiliser you can apply to comfrey, liming annually may be required to keep the soil sweet.
Harvesting and Propagating Comfrey
It is the second year when your comfrey patch starts to really pay off. In the spring it will leap back from its winter sleep and you can take your first cut that will get the potatoes off to a good start.
After that you should get at least a further 3 cuts – perhaps even 4. To produce further plants is easy, just 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. You can do this at any time but it is probably most effective to take your root cuttings in the spring.
Be careful as any bits of comfrey root left over may happily root wherever they fall.
