Willow is a common thing, so common often we do not know it when we see it. It makes up a green periphery, growing in unkempt lands, on verges, swamplands, the back of beyo nd where it blends in to the landscape quietly as if it had nothing to say. In the aptly titled book Willows (1972) Warren-Wren says: “willow is the Cinderella of the arboreal and horticultural scene, that has waited over an aeon of time for a fairy godmother to grant her wish to go to the ball”. Certainly willow has lived through the ages, through ice ages, a real pioneer, some 400 species of the genus are spread almost entirely across the globe excepting Antarctica and Australasia (where it has since been introduced). Long it has been used by working hands to fashion useful objects, while more recent applications further allude to this genus’s vast usefulness: land drainage, bio remediation, bio filtration, bio engineering and fuel production.
Photo 1: Catkins of Salix hookeriana catch the bright spring sun and provide fodder for insects, especially bees, at a time when food sources are somewhat short.
Being a Wisley Diploma student part of our coursework involves writing a dissertation and my chosen topic centres around the use of willow in horticulture. Recently as part of research for my dissertation I travelled to Ragmans Farm in Gloucestershire to attend a weekend course on the construction of living willow structures* delivered by Willowbank tutor Steve Pickup. Over a weekend we learnt all about willow: the history, identification, and commercial growing of willow, but the focus was on how to build a living hedge and dome.
Photo 2: Uprights are in place and binders are being added.
Living willow structures are best built in the colder months of the year, anytime after the plants have lost their leaves. We harvested long straight rods, called uprights and weavers and binders. Uprights provide the main backbone of the living willow structure while the latter two are used to strengthen and fill the hedge.
Photo 3: The finished fedge (living willow hedge) with Lily and Sam my fellow fedge builders.
Using a metal bar guide holes are made and each upright is inserted 30cm into the ground around 25-30cm apart. The black woven plastic matting acts as a mulch keeping weeds down while the willow gets established. Binders are used to hold the uprights in place and give the structure stability (they are not living). Next the weavers are inserted into the same holes as the uprights, and are woven through the framework created by the uprights. I like the architectural lines the arches and diamond patterns that the weaving creates.
Photo 4: An established living willow fedge.
Finally around each insertion point the earth is firmed in, a mallet or similar is a useful tool for this, this is a crucial step as it creates contact between the willow rod and the earth allowing it to become established. Generally living willow structures are maintained by a light prune in June/July and a hard prune (back to two buds) in winter. Alternatively new growth can be woven into the structure or harvested for use in dry willow crafts. In addition if all annual growth is removed there will not be many catkins produced (as these are born on previous seasons growth) so its worthwhile considering leaving some younger stems to accommodate for this.
Photo 5: The 15 year old willow arch.
Naturally some grafting will occur where willow rods cross, though this can be encouraged by applying and adapting grafting techniques. On the farm we saw a 15 year old willow arch which started as four uprights twisted together either side of a path, it was intentionally grafted together at the top where the uprights met but not on the sides where it had also grafted together.
Photo 6: Willow winter stems come in all colours - above is the nearly black Salix gracilistyla 'Melanostachys'.
I am not sure if this method of growing willow is enough to get Cinderella to the ball, but I think there is real potential to create something quite magical. Another fantastic use of willow is the method of coppicing or pollarding to produce bright stems of young growth with colours ranging from smoky white, greens, golds and reds, to nearly black. Different colours can be grown in groups to provide contrasting colour, brightening up dull winter days. Look out for excellent examples of winter stem colour grown around the lakes on Seven Acres at Wisley.
* I could not have attended this course without the help of the Professional Gardeners Guild who support full time horticulturists in a variety of ways including helping to fund courses which aid career development.