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.

Identifying medicinal trees and shrubs from winter buds

The winter woodland landscape may seem bare, but there is life stirring in the buds! One of the nicest things about seeing Holt Wood through the seasons is that we have begun to recognise trees during winter as a result of being able to closely observe the buds and bare twigs.  Perhaps we are fortunate to have trees that are relatively young (planted in 2005 or since then) and so their twigs are still low down so that we can readily see the winter buds. Some medicinal trees will stay smaller and shrublike (such as Cramp Bark, Elder and Witchhazel), others readily grow adventitious shoots on the main stem or trunk (such as Lime). Size, shape, colour and arrangement of buds are all useful to note. Buds can be terminal, on the end of the twig, or lateral, arranged in an opposite or alternate manner along the sides of twigs. Buds often have protective scales, if not they are considered 'naked'. Other identification features on the twigs include the scars from previous leaves and the lenticels through which air travels in and out. Here are some examples of buds seen at Holt Wood in early January 2013.

Cramp Bark (Viburnum opulus) has opposite plump and pointy coppery-brown buds in January in Devon. Each bud has two pairs of bud scales although only one pair is visible in winter giving a smooth appearance. The bark of this tree can be readily lifted in spring for use as an antispasmodic in powder or tincture form.

Elder (Sambucus nigra) buds are purple and almost bursting open in January in Devon, little patches of green shoots already peeping out at the base of opposite twigs. Twigs are greyish with raised lenticels.  The leaves are no longer used in herbal medicine (they are fairly noxious so can be made into an insect repellent), but the flowers and fruit are valuable in colds and flu.

Horsechestnut (Aesculus hippocastanum) buds are huge with large and richly coloured brown scales. Apart from the tip, the other buds grow in pairs. The medicinal use of this tree is based on the preparations made from the fruit such as an ointment for varicose veins.

Lime (Tilia x europaea) has plump and rounded reddish-brown buds alternating on short shiny twigs which can pop out almost anywhere on the smooth trunk. Each bud has 2 scales, one larger than the other. The flowers will make a superb relaxing tea.

Witch Hazel (Hamamelis virginiana) still has tiny yellow flower clusters in January hanging on from the previous autumn, these are accompanied by furry loose hand-like buds. A North American tree or large shrub and not a native to the UK, this shrub will provide leafy twigs for distillation in late spring.

Some useful online tree identification sources for the UK:

http://www.nhm.ac.uk/nature-online/british-natural-history/urban-tree-survey/identify-trees/tree-key/index.html#tree-s1-2 This site provides a 28 page downloadable tree identification key which has interactive steps and includes ornamental trees as well as native trees. Includes leaves, flowers, fruit as well as buds.

http://paulkirtley.co.uk/2011/bark-buds-common-european-deciduous-trees-winter-identification/ This site has a 'Bark and Buds' page with superb photos of 12 native trees to help winter id.

http://www.bbc.co.uk/nature/animals/wildbritain/field_guides/tree_id.shtml A BBC page on 'Trees in Winter' which has some useful examples of buds.

http://www.hainaultforest.co.uk/3Winter%20twigs.htm Very useful page with common winter twig photos.

http://cabinetofcuriosities-greenfingers.blogspot.co.uk/2009/11/tree-spotters-guide-to-buds-part-1.html A naturalist site based on North-east England with glorious colour close up photos of buds. 

Since some of our medicinal trees are North American natives, some useful ID photos for North America include:

http://www.ccfpd.org/NaturalResources/WinterTreeIDpocketguide.pdf A US site with superb winter photos of key North American trees.

http://www.florabymax.net/FLORAbyMAX/WinterBuds.pdf Another US site with a wide range of bud photos.

Latest at Holt Wood

Rain measure at Holt Wood

Wet Cramp Bark berries (Viburnum opulus)

Still raining and, despite some pleasant days in recent weeks, the ground at Holt Wood is saturated. Growth is lush, ideal conditions for sedges and mosses.  Just five apples harvested today, very tasty but a reminder of the difficulties for bees in pollination during the spring rain. Crops have been poor or  unreliable. Our St John's Wort has grown well but a lack of summer sunshine led to slower production of flowers. Fastgrowing plants do not seem to concentrate the key constituents needed for medicinal use. On top of this, the wet has made it problematic to strim down weeds and to maintain paths for access. All rather drippy and depressing!

Given the damp conditions, we are looking at possible plants which may be more successful. Some, such as Meadowsweet (Filipendula ulmaria) and Valerian (Valeriana officinalis) are well-established and can be harvested for medicinal use. Some additional plants to consider might include Bogbean (Menyanthes trifoliata) and Yellow Flag (Acorus calamus).

Meanwhile, perhaps unsurprisingly, we have been busy doing other stuff with family (looking after grandchildren) and acquiring a new puppy. Lucy is 13 weeks old, she is an Irish terrier, and a welcome addition to the family. She will be a working wood companion, and has already enjoyed several trips to Holt Wood.

Lucy inspects the moss

Looking ahead we have a Wood Working Day planned for 10-4 on Saturday 27th October 2012. Weather permitting this will be an opportunity to welcome interested visitors to the project, walk and talk, attempt some clearing of branches left from previous pollarding activity. Email to to let us know if you plan to come/ need directions.

Finally, we were glad to see a feature article 'More bark to the bite: woodland can provide a sustainable source of bark' by Anne Stobart, published in Smallwoods magazine (Summer 2012 issue 47) - the Small Woods Association are at http://smallwoods.org.uk/.

To harvest or not to harvest

Bugle, Ajuga reptans

We have had lots of bluebells, making a sea of blue. Another spectacular plant is Bugle (Ajuga reptans), a member of the mint family (and quite easily confused with Selfheal, Prunella vulgaris, another purplish mint family member). Bugle seems to like a dampish location with some drainage, and grows plentifully  in several large patches on a sloping ride, gradually spreading by runners. It is traditionally reputed as a wound herb, the leaf good to stem bleeding whether made into a decoction or as fresh poultice. John Quincy (1730 edition) in Pharmacopoea Officinalis & Extemporanea mentions Bugle in passing when listing 'agglutinents' like Cranesbill, Hound's Tongue, Plantain, Shepherd's Purse and others. Culpeper recommends making a syrup. But we have not harvested this plant – it is far to attractive to bees and seems to be an important plant flowering for them earlier in the year. 

Pollarded Violet Willow, Salix daphnoides

Stumps after pollarding

On the other hand, we have had to be decisive and begin to harvest some of the faster-growing trees, otherwise they will become impossibly big and crowded. However, we keep having second thoughts about cutting down trees. The original intention was to coppice our willow and others on a cycle of years long enough to allow a good return of tree bark. In the effort to get the whole project established many of these trees have been left undisturbed for as much as six years. By trial and error I have found that Violet Willow can be pollarded at 4 to 5 feet height and will then produce a number of good size branches in subsequent years. So I have started to pollard more White Willow, Violet Willow and Cramp Bark trees to try to better understand this process. There are a number of questions that need answering – should the first 'pollarding' be carried out before a certain age, can pollarding be done when bark is easy to harvest, how is pollarding different to coppicing at the base of the tree, does pollarding height matter etc etc? So I will be trying to figure out some answers by monitoring the progress of these trees over the coming years. The stumps do look rather forlorn and bare right now, but the ground has been opened up to allow other plants to grow, and hopefully the trees will recover to provide an ongoing pollardable source of bark.