Harvesting Cramp Bark (Viburnum opulus)

Harvesting Cramp Bark (Viburnum opulus)

Harvested branches of Viburnum opulus

Remaining stump will shoot vigorously

Tough bark

Smooth and easy to remove bark

Cleaned up Viburnum opulus ready for bark removal

The sap has been rising in our Cramp Bark shrubs, so leaves are appearing and it is a good time to harvest bark. We selected shrubs which have been growing since 2006 and are well-established alongside a grassy ride. Our permaculture design provides lots of 'edges' for shrubs and trees like this.  The shrubs were cut by hand down to within about 20 cm of the ground, leaving substantial stumps. The branches were then sorted out for quality of bark (see pictures). Fatter and older stems have bark which is less easy to remove, have many knots and bends, and are often dirty from rain splashed-mud. Bearing in mind that it is likely that the active constituents are greater in younger stems, we sought out the longer smooth and straight stems from a pencil size width upwards, mostly up to 2 or 3 years old. The youngest stems are easy to strip of leaves by running a hand up and down, the older ones need to be trimmed of side shoots with secateurs. Once cleaned up in this way, we found that the rising sap makes the bark easier to lift from the stems- making a lengthways incision, the bark will lift away cleanly in sections which can be cut short, or broken off at leaf axils. More on the processing of the bark in future posts

Coppicing of a number of shrubs together means that we have opened up the area to light and warmth. Taking the opportunity to clear out reeds and brambles at the same time, this will give other smaller plants a chance to get going. The area where we harvested  is low-lying, near a riverside meadow and often waterlogged for short periods in the winter. The Cramp Bark seems to relish this relatively moist and fertile environment, which is somewhat shaded by taller willows and alders around. Based on previous experience, this coppicing will produce vigorous growth from the base and long straight shoots which can be harvested in 2 to 3 years time. Meanwhile, we have noticed Skullcap (Scutellaria laterifolia) growing nearby, but struggling against taller grasses and lack of light, and hope that this will be encouraged by the extra space and light, to provide a viable harvest later in the year. Alongside these Cramp Bark shrubs are some willows which have been previously cut back and they can form the basis of further coppicing next year.

Harvesting Cramp Bark

First coppiced bark harvest from Cramp Bark (Viburnum opulus)

This small tree, or shrub, has opposite leaves and its growth habit tends to be multi-stemmed, forking towards the end of branches as flowering terminal buds are used up. So the plant has quite a bushy appearance with, after 5 years, many stems. It enjoys a moist woodland location. Sometimes it is called Guelder Rose or Snowball Tree, but these names should only be used for the ornamental variety which has sterile round-shaped heads of flowers. In April I harvested stems of Cramp Bark about 20 cm up from the ground. After removing leaves and soft growth branching off the main stems I could readily pare off the bark in short sections from stems at least pencil size thick. The leaf and soft growth can be composted or make an ideal mulch to suppress weeds.The harvested bark was dried in a single layer on trays in the dark in an airing cupboard for about 4 weeks till crisply dry. It was then passed through several grinder screens in a heavy duty grinder (see pictures). The resulting fine, brown powder will be used in filling capsules or for percolation as a tincture. The plants that have been coppiced will recover and be harvestable again within 3 to 5 years.