An assessment of the lever and mulch method of rhododendron control.
Jessica Hodges (2009). BSc Hons. Thesis, University of Edinburgh.
Conclusions
Sites treated with the L&M method showed no R. ponticum regeneration (once the follow up treatments had been properly developed) and far from the mulch layer inhibiting ground flora, significant recovery was observed within as little as 3 years. This is an impressive result for a method still in its infancy and warrants further research into the possibility of widespread application.
L&M is a method based on a fundamental understanding of the plant it targets and as such it should be considered a model for tackling other pest species. This understanding is what makes it a successful technique and the biodiversity benefits it offers potentially make it an important new tool in the fight against rhododendron.
Practical recommendations
I would recommend that this method be trialled in other locations especially in special areas of conservation or locations with sensitive ground flora. A course to train other operatives in the method and a handbook to disseminate information about it are the next steps. Due to its environmental benefits when compared to other methods I would recommend implementing this method on a large scale to tackle rhododendron as soon as it is practical.
Highland LBAP Review:
Lochaber Implementation Plan, 2007-2010.
Project implementation and outputs:
The Lever and Mulch method is a highly effective, efficient and relatively inexpensive technique for eradicating Rhododendron ponticum. Plants are effectively dismantled and are uprooted, by hand. The only tools required are small handsaws to exploit natural weaknesses of the plant's growth form and to make best use of leverage. Stems that fail to be uprooted are left with as few buds as possible, so that regrowth is weak and minimal. Uprooted or cut material is not dragged to fires, but is used to mulch all stools that remain with any buds. This not only kills most plants that happen to be left with any buds, but it also leaves a minimum area available for seedling establishment after initial mature plants are killed.
A very high percentage of plants are thus killed outright at the first operation and follow-up work has proved to be extremely easy and efficient. Simple bud-rubbing (with further mulching, if required) has proved to be a highly effective way of killing any plants that do show signs of recovery, particularly if it is undertaken before the first winter following the initial operation. No machinery and no chemicals are needed at any time. Unlike 'cut/burn/spray' methods, there is no need to wait an extra year for regrowth to be sufficient to absorb fatal doses of herbicide, nor for brash to be burned or removed from site to allow access to every stool for spraying. Winter (or the full period from autumn to spring) has generally been found to be the best time to undertake the L&M method. The plant itself appears to be more brittle at this time of year than during the main summer growing season. Access also is generally easier (when bracken, nettles etc., are died back) and (most important of all), there are no midges!
The Highland Council
Local Action for Wildlife
The "lever and mulch" method of Rhododendron control requires no power tools, no fires and no herbicides, just an understanding of the inherent strengths and weaknesses of Rhododendron ponticum and lots of elbow grease. Branches are cut in strategic places to form effective levers (and to disentangle them), then the stumps are either levered out the ground in their entirety, overturned and left to dry, which kills them, or, if part of the stump is left in the ground it is covered (mulched) with the cut branches and leaf litter from other bushes. This kills almost all of the plants but if some re-sprout they can be removed relatively easily [with a hammer].