Herb Fascination: Comfrey

Comfrey, Symphytum officinale L., aka Blackwort, Bruisewort, Healing herb, Knitback, Knitbone, Ass-ear, is a hardy perennial herb you use the leaves from. It grows 3’ – 4’ high and can be found in wet places, roadsides, ditches, and waste places. Zones 3 – 9.

This was planted in the first herb garden on the west side of the house in June 1992. It has done alright there all these years, never once volunteering to become invasive.

Here it is in June 2006

And in May 2015.

When I reopened the Big vegetable garden I planted comfrey in the spring of 2011 as I had heard it was a dynamic accumulator, and also that it had high protein and calcium in its leaves. There’s some debate but it can be fed sparingly to layers and I intended to do that.

This is June 2017 and it’s done very well in the vegetable garden, and only in the last year or 2 have I found the occasional sprout where it did not belong.

In early May 2012, the Montview Farm had a Plant Diaspora as it was being shutdown. I took 3 dwarf comfrey plants to put under my McIntosh tree.

This is 3 years later in May 2015. It has filled in the area under the tree, but has not offered to spread outside that area.

Flowers: pale yellow, white to purplish bell shaped flowers that bloom in clusters from May – September. Stem of flowers is 1 sided with each pair of leaves.

Leaves: oval, alternate, hairy, dark green; lower leaves up to 10” long and 8” wide, on stiff hairy stems that branch at the top

Cultivation: full sun but will tolerate semi-shade, likes nitrogen rich soil with a neutral pH. Plant 2’ apart. Give each plant a bucketful of crude manure each spring and in late summer. Take root offsets at any time except during winter. Will re-bloom if deadheaded. Plants have a taproot that can reach down 10’.

Leaves can be harvested at any time and used fresh for poultices or dried/dehydrated for feeding to layers. There are many medical uses for this plant, but I’ve not yet tried any.

I’ve dehydrated the leaves and flower rays to feed to the layers over the winter.
The leaves contain 35% protein and are useful as fodder for livestock.

Heavy internal use is discouraged due to certain alkaloids in the plant tissues. Heavy use is thought to cause liver damage.

The leaves can be soaked in water for 4 weeks for a compost tea that’s high in potash. Boiled fresh leaves make a golden brown dye. Comfrey is a good compost addition.

References:

Field Guide to Herbs page 334, 144
Encyclopedia of Herbs page 357