Emma O’Neill, head gardener at sustainable gardening charity, Garden Organic, explains how to use comfrey
Beautiful bee-friendly flowers, healing leaves and a highly nutritious plant food. There’s a lot to love about comfrey.
As an organic gardener, I have long been aware of the virtues of comfrey. Common comfrey has been cultivated as a healing herb since at least 400BC, with the leaves used to make a tea to soothe all kinds of ailments. Its botanical name is Symphytum officinale meaning ‘growing together of bones’, and its common name in English is ‘Knitbone’.
Common comfrey is a rhizomatous herbaceous perennial – a member of the borage family – with hairy dark green leaves growing up to 10in (25cm) long on erect stems. These are followed by tubular flowers, which range from purple, pink or creamy yellow. They appear in May, often earlier now in our milder winters, flowering right through to a hard frost.
Comfrey isn’t very fussy, growing happily in any aspect - exposed or sheltered, sun or part shade. They like moist but well drained soil, with the occasional helping of well-rotted compost, and are easy to establish from root cuttings or division.
But beware! As a perennial, plants can live for 20 years or more, so ensure you plant them carefully in the right longerlasting space. Common comfrey will selfseed readily, being almost impossible to remove once established. Which is why, at Garden Organic, we recommend the ‘Bocking 14’ strain for home growers.
The benefits of ‘Bocking 14’
In 1950, our charity’s founder Lawrence Hills set up a comfrey research program in his home of Bocking near Braintree, trialling several strains, each named after the village.
It was during these trials that he identified what we now know as the ‘Bocking 14’ strain of comfrey or Symphytum x uplandicum. This nutrient-rich strain has the bonus of being sterile, so it won’t self-seed like many of the other varieties, and is therefore perfect for growing in a garden or allotment. Plus, it has one other clever adaptation. ‘Bocking 14’ has an extremely long tap root - up to 6ft (2m) long in some cases - and this penetrates the soil and takes up the nutrients that are inaccessible to other plants. These are then used throughout the plant, with all the goodness ending up in the leaves.
How to use comfrey
Comfrey plants contain high levels of nearly every nutrient a growing plant needs, including nitrogen, phosphorous and potassium. Hungry plants such as tomatoes and peppers, or containergrown plants, really benefit from these added nutrients.
One of the easiest ways for other plants to access these nutrients is to use the leaves as a mulch. Simply put the leaves around the base of the plants you wish to feed, or chop them up first to speed up decomposition and allow the nutrients to go back into the so
