Guide to Growing Blackwort - Symphytum
Members of the Symphytum genus are hardy perennials herbs that range from 30 cm to 1.2 M in height.
Depending upon variety they may bloom from the latter part of spring until the first frost of winter.
Symphytum has attractive varicolored leaves and carries clusters of small pink, blue, purple, white or yellow bell shaped flowers.
Some common names for members of Symphytum include Blackwort, Knit-bone and Comfey.
If growing as a herb, harvest the leaves after three years of growth just before flowering occurs.
How to grow Blackwort, Comfey and other Symphytum
It is best to grow Comfey, Blackwort and other members of the Symphytum genus from root cuttings; these should be buried in autumn or early spring at about 10 to 15cm deep with a spacing of about a metre. Ideally Symphytum will grow in a sunny part of the garden where they will thrive, they will tolerate shady conditions. Blackwort and other Symphytum like a rich soil of pH 6.5 to 7.5 that is kept moist.
Caring for Blackwort
Blackwort and similar species take a little bit of caring for. They like a moist soil so keep well watered. Divide the plants every year to stop them growing too close together. In the autumn it is necessary to remove dead Blackwort leaves. If you require more plants then Symphytum can be propagated by taking cuttings from the root in the spring, or easier still plant out divided plants when tidying up.