This week our woodland and development team have been up to something a bit different!
Expert Willow Weaver Phil Bradley was brought in to teach our team the technique of Willow Spiling, an old traditional method for retaining stream banks. The erosion to the streamside here at Harlow Carr has been a concern for a long while & it's great to finally have something done, albeit a small amount!
We began by driving large live willow stakes vertically into the riverbed about half a metre apart. Long willow shoots (osiers/withies) made up of varieties of Salix fragilis spp. were then woven into place horizontally between and around the stakes. Tucking them in at the ends and leaving them a little rough on the face will allow the shoots will more successfully capture sediment and slow down the water flow.
The area behind the willow barrier was then back-filled with soil to allow the roots to anchor in and establish. Come Spring the willow puts out root growth into the bank and the river bed, binding the two together. Coppicing or pruning willow from this stretch of hurdling will be used next year for another stretch of spiling. It is in effect growing spare parts and proving its own sustainable credentials.
A huge advantage to spilling is its potential to resist flash flooding, which regular visitors will know, is very useful for us at Harlow Carr!
After the mornings tuition Phil stood back as we seemed to have grasped the concept fairly quickly and we were all pleasantly surprised at how professional it looked at the end of the day!
Come along and see what you think of all our hard work.
Mark Herron - Supervisor Woodland