Common name: Knitbone

Comfrey symphytum officinale is a very versatile plant to have around in the allotment or garden, particularly if you are growing organically.

It is a frost hardy herbaceous plant that will thrives in most types of soil.

Under its common name knitbone it was traditionally used in the past as a poultice to heal broken bones.

It is high in calcium, which may be why it was used in that way.

Comfrey symphytum officinale


Propagation is by root division so you may have to cajole a neighbour for a piece of root in order to get started.

Be careful when growing this plant as it can be a bit of a thug, it spreads quite rapidly and may establish itself in areas where you don't wish it to.

Consider containing the root system in a bottomless bucket or similar.

Properties and Uses:

Comfrey is a complete fertilizer in so far as: its leaves are full of calcium, iron, magnesium, nitrogen, and potassium.

The leaves can be harvested growth several times a year from mid spring onwards, and the aforementioned properties make it an ideal compost activator in the compost heap.

Its uses are many, here are a few;

The leaves and stems can be used as a mulch for many types of plants, vegetables in particular.

It can be used as a soil conditioner if placed directly in trenches before planting.

Leave the leaves in the sun for a few hours to wilt prior to using them for any of the above tasks, this will reduce the possibilities of it setting roots.

It is a useful plant to grow on new plots where its very deep root system can break up heavy clay soils.

If used for this purpose then moved at a later date to allow cultivation, ensure that every piece of root system is removed or it will keep returning year on year.

Its leaves can be used to create a nutrient rich liquid fertilizer.


Place comfrey leaves in a container add a small amount of water and leave for a week or two.

Drain off the liquid produced and then dilute it by adding ten parts clean water to one part comfrey liquid.

This resulting liquid feed is excellent for supplying potassium hungry crops, for example tomatoes.

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