Some species do self-seed, however propagation by seed is very erratic. Sow seeds in autumn and place in a cold frame for 3-23 weeks until germination. The easiest method is by root cuttings taken in spring. Cut tap root into 2cm sections and cover with 5cm of river sand. Keep moist and will shoot in 2-3 weeks. Established plants can be divided in autumn. Any piece of root that is left in the soil will create another plant.
Comfrey prefers moist soil in sun or partial shade. It is ideal for clay, though it will tolerate all but arid conditions. Choose position in the garden with care as S.Officinale will self-seed and, because of its tap root, it is nearly impossible to remove once established. Comfrey can also be grown in large containers using garden loam with ten per cent added coarse grit.
Comfrey requires ample nitrogen so an annual top dressing of rotted manure is recommended. Some strains are prone to rust, when water-stressed, and powdery mildew. With both diseases, cut the plant down to the ground and burn the contaminated leaves. When growing plant for leaf harvest, do not allow the plant to dry out in summer.
Leaves can be harvested up to 4 times per year. Cut with shears and wear gloves as the tiny hairs on the leaves are an irritant. Cut the leaves before flowering from early summer until autumn. In autumn dig up second-year growth roots for frying.
Roots and leaves
How to use
Comfrey has a remarkable reputation for hastening the repair and renewal of damaged tissue and has been shown to have a regenerative action on connective tissue as well as reducing inflammation. Traditionally, comfrey has been used as a topical application in the form of a poultice and a cream or ointment. Read further below so see how you can make your very own comfrey poultice from S.Officinale at home to heal bruises, fractures and wounds.
A poultice is a topical application of a fresh herb which is most commonly used to encourage healing of injured muscles and bones, strains, sprains and fractures.
- Chop sufficient fresh comfrey leaves, place in a container and blend using a stick blender. Add a little water to aid the blending. The finished mixture should be a mushy consistency
- Spread the mixture thinly on a piece of folded muslin cloth, enough so that the surface area will cover the affected area.
- Rub a little body oil onto the affected area to prevent the poultice sticking to the skin. Apply/wrap the poultice to the area and cover with a bandage or plastic wrap to hold the poultice in place. Change the poultice about every couple of hours or if possible leave it in place overnight.
Comfrey is also more popularly known as a compost accelerator. Leaves can be added to the compost heap in between layers to speed up the decomposition process as the heat it releases accelerates decay and kills weed seeds. Comfrey leaves rot down quickest and are high in minerals which feed the compost. Comfrey also, being rich in potassium, calcium, iron and manganese, is perhaps the best natural fertilizer nature can offer. The liquid feed made from this herb is ideal for foliar-feeding and as a tonic for restoring mature garden plants. Follow the 5 easy steps below to make your own organic liquid fertilizer from comfrey leaves.
Organic liquid fertilizer:
- Wearing gloves, pick handfuls of comfrey leaves in the early morning when they are at their freshest.
- Pack leaves into a rust-proof air tight container and weigh then down with something heavy like stones or a concrete block. Cover with the lid and place in a warm position out of direct sunlight. (An 8 litre bucket packed with leaves will yield 1.2 litres of comfrey concentrate) Optional: add 600ml rainwater.
- Leave for 3-4 weeks and then check the progress of the decomposition into the liquid concentrate. The leaves should have started to rot down producing a murky brown liquid. If you cannot see any liquid then leave for an extra 2 weeks.
- Once the liquid is produced, discard any leaf material by straining the liquid through a muslin cloth. This concentrated comfrey feed will keep for up to six months if stored in a screw-top bottle out of direct sunlight.
- Voila! You have just worked with nature to make an all organic natural liquid fertilizer. Dilute concentrate with water as described below to make a root or foliar feed.
Root feeding in watering can:
Dilute 25ml per 1 litre of rainwater
Foliar feeding in hand-held pressure sprayer:
Dilute 12ml per 1 litre of rainwater
DO NOT take comfrey leaves internally as may cause toxicity of the liver.
DO NOT use if pregnant or breastfeeding.
McVICAR, Jekka. 2013. Grow Herbs: An inspiring guide to growing and using herbs. London: Dorling Kindersley Limited.
THE READER’S DIGEST ASSOCIATION, INC. 2009. The complete illustrated book of herbs. New York: Adult Trade Publishing.
INFORM AFRICA, (2012), Comfrey Medicinal Use [ONLINE]. Available at: http://www.informafrica.com/health-africa/comfrey-uses-the-medicinal-benefits-of-comfrey-plant/ [Accessed 21 January 15].
MASCLEF, Amédée, (2001), 225 Symphytum officinale L. Atlas des plantes de France. 1891 [ONLINE]. Available at: http://commons.wikimedia.org/wiki/File:225_Symphytum_officinale_L.jpg [Accessed 21 January 15].
JOSH & BRENT, (2012), Comfrey Poultice [ONLINE]. Available at: http://beekman1802.com/comfrey-poultice/ [Accessed 21 January 15].