In English, the word comfrey is used as the
general name for Symphytum species. The same term has been in use
in various languages since at least the 1st Century. Pliny, a Roman,
called it conferva. This later became cumfria, then (Old French) confrie, and,
with a few alternatives in between, eventually the English spelling of today.
Symphytum is derived from Dioscorides, who was contemporary with Pliny, and a
Greek physician. His word for comfrey has been variously reported as Syumphuo,
Sumphutum, Sumphuton and no doubt other similar words. Symphytum officinale
or Common Comfrey (so called because it was the common species in Britain) with
white or cream to yellowish flowers also has a red to purple flowered variety S.officinale
var. patens. It is totally erroneous to refer to S.officinale as
“True” comfrey as some Internet sites do, since about 40 species of Symphytum
have been identified. They are native to most of Europe and Western Asia
and all are called comfrey in English, the norm being to use a descriptive term
or place-name before the word Comfrey, e.g. Prickly Comfrey or Palestine
Comfrey. Symphytums cover the range of colours from white through to
yellow, and blue through purple to red. The Common Comfrey was introduced to
North America at least as early as the 17th Century, Josselyn (1672)
calling it comferie. Some of the other comfreys followed at later dates and
some have also been taken to other parts of the “New World” and Eastern Asia.
Some current day herbalists believe that S.officinale
is the preferred, or even only, species for safe medicinal use, Officinale
meaning “of the (herbalist’s) shop”. They may well be correct, but historically
more species have been used. S.officinale is uncommon, or absent (and
other species are common) in some areas where comfrey has traditionally been
used medicinally. With 18 of the species in Turkey alone, it is not surprising
that Dioscorides was familiar with, and apparently used, more than one species
since presumably nearby countries have at least several of the species found in
Turkey. Gerard in his Herball gives an unusual use for the root juice in
ale; it is “given to drinke against the paine in the back gotten by wrestling,
or overuse of women”.
Of most interest to those people wishing to use
comfrey for plant food and livestock feeding are hybrids, specifically of the
species Symphytum x uplandicum, a cross between S.officinale and
another Symphytum and now widely known as Russian Comfrey. S. x uplandicum is a naturally occurring
hybrid, the original being found in Uppland, Sweden and not Russia. Later
discovered hybrids were from Russia.
These hybrids rarely set seed, but will provide the pollen to cross with
S.officinale and give yet another variation. Borage, Borago
officinalis can also provide pollen to produce a hybrid. Both Borage and
Comfrey are in the family Boraginaceae. When an unsorted mixture of
varieties of S. x uplandicum was sent to North America from
Britain in the 1950s there was a “Cold War” between the USA and Russia, so it
was given the name Quaker Comfrey. Lawrence Hills was instrumental in exporting
this mixture and he was the founder of the Henry Doubleday Research
Association. The HDRA was named in honour of Mr Doubleday, who was a Quaker,
and he had probably the first ever Russian hybrids in Britain, sent to him by
the Head Gardener at the Palace of St.Petersburg.
The most common cultivar in use amongst
gardeners and livestock people is S. x uplandicum ‘Bocking 14’
but some, such as myself, use ‘Bocking 4’. Together with all the other
Bocking cultivars, at least 21, these were first identified by Lawrence Hills
from amongst a large assortment of collections from various people and places.
He called each collection a strain or mixture after the people or places where
they originated. He did not breed or “develop” the cultivars as is often
reported, they already existed, but nobody before Lawrence Hills had identified
them as separate cultivars of the same species. In this context please note
that a lot of current Internet sites replicate other sites in their supposed
“information”. Lawrence Hills warned against such incorrect repetitiveness long
before the Internet was invented. He
made great efforts to identify some of the highest yielders, but time and space
prevented him doing long-term trials of every hopeful, so if you have a mixture
there could be a world-beater amongst them.
All comfreys only actively grow from spring to
autumn in temperate climates, dying down before mid-winter, and timing
depending upon how “temperate” the climate is. In tropical climates they will
grow year round if there is not a long dry season and in temperate areas with a
long dry summer they need irrigation for high production. S.officinale sets
seed that germinates very easily. So do some of the other Symphytums.
Stick to the Russian hybrids if you want to control the size of your plot.
Anyone buying named cuttings of a Russian comfrey hybrid, whether root or crown
cuttings, also called crown sets or offsets, should find that all plants are of
the same cultivar. That means the flowers will all open with exactly the same
colour, and fade to the same colour, although there could be some slight
variation during the phase from fully open to faded. If the flowers are not all the same then you have a mixture, and
will need to do your own work on identifying the high yielders, just as
Lawrence Hills had to do.
Knowing the wide variations that Lawrence Hills
found in his mixtures I collected samples of as many collections as I could
find when I farmed in the North of Scotland prior to moving to Portugal, with a
view to trying to find something that might outyield the Nos. 4 and 14 I
already had, along with some S.officinale. I failed to find one in the
collections I acquired. I did not have many years to experiment, up to about 7,
but with only around 100 plants it was not difficult to spot low yielders and
anything that looked promising. Nothing I had acquired was near the 4s and 14s
for yield.
I operated a commercial free range egg
enterprise on this farm, using mobile night shelters holding either 80 or 120
hens and the hens had free access to all the comfrey beds. They were not
interested in the plants at all. This is not unusual, and if you want to offer
comfrey to poultry it is best to cut and wilt it first, possibly even chaffing
it. I understand this is particularly important for No.14. Poultry apparently
find the higher potassium content of this cultivar distasteful when it is
growing or offered freshly cut. On the other hand I have heard of people being
able to feed it fresh, so it is worth a try if you want to feed it to poultry.
I did not attempt wilting and chaffing because I was not interested in feeding
it. I had a specially formulated layers’ ration made up for me and delivered in
bulk pelletted form. The hens did pick up various tidbits every day, including
some greenstuff, but being on a commercial basis, I had regulations to meet as
well as endeavouring to sell particularly high quality eggs, and wanted the
hens to concentrate on eating the ration I provided. Too much greenfeed can
colour the albumen and give an “off” taste.
I kept meat rabbits until the increasing egg
enterprise meant I had to cut back on the workload and the rabbits had almost
all taken readily to most comfrey leaves they were offered. Some did not like
it fresh, wilted or dry. Those that did saved me the cost of bought in hay.
I brought a couple of crown-sets of No.4 with
me to Portugal because, following the advice of Lawrence Hills, this is better
suited to livestock and I intended to use it primarily for this purpose, the 14
with its higher potash being preferred for plant food, although both can be
used for stock; as well as in compost, as a mulch, liquid fertiliser, dug into
the ground or laid in drills underneath potatoes. As it happens my land is
naturally high in potash so the lower level in the No.4 is not a problem, and
the amount is still substantial in any event. One of the analyses made by the
HDRA showed No.4 to have 2.35% Calcium; 1.25% Phosphoric Acid (about 0.9% of
the P in the N:P:K figures shown on fertiliser sacks) and 5.04% Potash. An
analysis of No.14 on another occasion showed 7.09% Potash and lower Phosphorus,
with an analysis of No.15 showing similar results to the No.14. Mineral content
of the leaves will alter over the course of a season, and I may have my own
samples analysed.
I increased the plants from crown sets but only
to about 30 plants. I keep a small goat herd of up to 20 does, and they have
never been particularly fond of comfrey, often pulling the leaves out of the
feeders to try, and then discarding them. I tried many times each summer with
only a few does and kids being interested – until this year which began with a
particularly dry winter and the usual dry summer, therefore no fresh grazing
and very little browse.
Most of the goats took to the comfrey by about
the end of July, and my limited stocks had to be fed very sparingly. I have
increased the number of plants I have and earmarked another area for a further
increase in the spring in the hope that the goats will continue to readily eat
comfrey. I hope they do because it makes an ideal complement to maize and beans
with a reverse Ca:P ratio to them. Comfrey is higher in calcium. It is also
high in protein so can at times replace the beans. I feed some grain and pulses
or concentrate all year round, but more in spring and late summer when the
comfrey is available and there is limited grazing, either because the fields
are shut up for hay in the spring, or because of the dry Iberian summers when
pastures do not grow. These two times also coincide with peak lactation of the
does and the flushing period (see the Amazing Maize blog). If the goats decide
not to eat the comfrey then I shall use it as a mulch around fruit trees.
Whether or not the goats do eat the comfrey I
intend to trial it in the Ribeiro Grove of 180 olive trees which I finished
planting earlier this year. It will be labour intensive but I believe will be
worth the effort. At 6 metres spacing of the trees a comfrey plant can be
placed 2m each side of the trees to give two plants per tree. The olive trees
have a fairly small root area for a number of years, and not a particularly
large one when mature so the comfrey and olive roots will not be competing for
space in the soil. The nutrients which the comfrey removes from deep in the
ground is kept in the same area under this system, so whilst the soil is being
mined, concentrated minerals are returned no more than 2m away and the land
does not lose them. Instead they are recycled. Harvesting the leaves and using
them for any purpose elsewhere means that the comfrey land loses nutrients.
Obviously some of the nutrients will be locked
up in the trees, and the olive harvest will remove some, as does any cropping
between the rows, such as the maize this summer, and a current crop of beans.
These nutrients need to be replaced, and since I will be fertilising for the
crops, they will be. The comfrey and trees will automatically receive their
share of the crops’ fertiliser since I use a broadcaster across the whole
grove. The area is irrigated via overhead sprinklers and my other grove, the
Estrada Grove of 299 trees planted in 2006, is irrigated through drippers,
which means that the irrigation is only along the tree lines, but consequently
also suitable to take comfrey plants. That is a possibility for the future, but
this area is only fenced to grazing livestock standards, and wild pigs
occasionally make a foray. I am sure they would destroy a comfrey crop the same
as they do a maize crop, so the boundary would need to be pig proofed first.
Another means of using the comfrey would be for
me to make liquid manure, simply allowing the comfrey to liquefy inside a
container and draw-off the concentrated liquid fertiliser. This could then be
fed through the irrigation systems. I have some filters on the lines, but
anyone planning on doing this might find that additional fine filters are
needed for drip irrigation systems otherwise the drippers can become blocked.
The overhead sprayers would not be a problem since they would not block with
small pieces of vegetation. If I do use this system, then I will have the
concentrated liquid analysed.
