Les Trognes…und der Dachplatane

June 26, 2012

Yesterday at the research nursery we had a unique and fun opportunity to do some pruning work with Louise Levy of Levy Tree Care in Duluth, MN.

Besides her work in Minnesota as an ISA Certified Arborist, Louise has had many opportunities to travel and work in France, Belgium, and Germany – studying and practicing pruning techniques and styles that are both very old and, in many cases unknown to American audiences.  We’ve been talking about “alternative” pruning and training practices for some time, we finally brought it back home!


Dachplatane - Before

One of the first techniques we experimented with is called Dachplatane, which means “roof tree” or “umbrella tree” in German.

While normally applied to a London Plane tree (Platanus x acerifolia) we tried it on a Northern Acclaim honeylocust; definitely not a direct comparison, but the tree was already moving toward this canopy structure – and additional work made sense!  One interesting and inspiring approach to this tree was Louise’s desire to work with existing leans or bends (due to wind) rather than our typical “pull ’em up straight” mentality.  The resulting tree is interesting and should provide for many years of discussion and continued experimentation!











Dachplatane - After






Here is link to a site Follow this link to a website showing the steps for creating Dachplatane (in German).  

This also shows the support structure used to create the “roof”, which we have yet to install.











Tower Poplar - Before







Now, moving on to pruning practices seen commonly in Belgium and France, we chose a “volunteer” Tower poplar (Populus x canescens).  This tree is a root sucker from a parentright next door and almost begged to join in the pollarding party!










Tower Poplar - After







Jonathan, one of our summer research assistants tested his saw blade with this foreign, yet exciting, method of pruning!

We’ll be sure to continue the intensive and recurring pruning required to establish the callus/woundwood heads on this tree!








Black Alder - Before






Our final subjects included a couple European black alder that had severe winter kill last winter. 

Lacking their definitive central leader and upright habit these trees were great candidates for something new and different!














Black Alder - After

Using techniques usually described to create “Les Trognes” in Belgium and France, we brought these trees into a new light and hope to have many more years

to follow their progress and continue their work.

PLEASE NOTE:  This should be considered experimental work for our region.  We are working with species not normally used for these techniques and are interested in testing their suitability for success! 

These pruning and training practices have undergone centuries of practice throughout Europe – but on native-European species that have a very long track record of success. 










We’re testing local species and varieties, hardy to Minnesota and the Upper Midwest to track and test both their response and performance after this work.  Please check back often for more updates!


…and one final shot for inspiration!

Les Trognes in Paris (photo courtesy of Russell Kennedy)

Les Trognes - Paris


by Chad Giblin