Team Tree Blog

Les Trognes…und der Dachplatane

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

Final Preparations for Grand-Opening of the High Bridge Dog Park

Alongside foresters of the City of Saint Paul in a partnership with Excel Energy, we worked a full day this week putting the final touches on the trees at the new dog park near downtown Saint Paul. The park was converted from a train car and coal storage site into a spacious, beautiful inner-city gathering space complete with an astounding view of downtown Saint Paul.


Tucked underneath the towering High Bridge, this 7-acre park features a large variety of trees, ranging from shade trees like the DED-resistant American elm Valley Forge, which will one day tower over the site, to the ornamental Showy Mountain Ash known for its beautiful white flowers. All told, 156 new trees were planted by excited volunteers on Arbor Day 2012.

Map of Trees on Site (click here)

Not only will these trees provide beauty and shade to the park, but serve as part of an ongoing study by the City of Saint Paul Forestry Unit and the Department of Horticultural Science at the University of Minnesota.  Aimed at testing the capability of various promising species to survive and flourish throughout the city and in harsh urban conditions in general like the compacted, coal contaminated soil of this particular site.

The grand-opening will be held Thursday, May 31st at 5:30 p.m. and will be hosted by Mayor Chris Coleman among others. Bring your pup, share in the excitement of Saint Paul’s second City maintained dog park, and admire the growth of these young, beautiful trees!

View larger map


Project Update:

The opening on May 31st was a huge success. The park was filled with dogs and dog-owners alike, excited to check out the brand new park.  Among others, Mayor Chris Coleman and CEO of Excel Energy Judy Poferi brought their dogs to celebrate its opening.

The park hours are set from sunrise to sunset and normal dog park rules apply.

Exciting to watch both young trees and community continue to grow on this site.

Thumbnail image for Thumbnail image for Thumbnail image for Dog's @ High Bridge Dog Park.JPG

High Bridge Dog Park official website

by Charlie Lehnen

High Bridge Dog Park – Arbor Day 2012

On Arbor Day 2012 volunteers planted 156 trees near the High Bridge in Downtown Saint Paul!High Bridge Map.jpg


This new dog park will be home to several new varieties of trees! These new species are being tested for possible use throughout the city and will be tested for survival, performance, and growth rate. 

Different soil amendments will also be used to find new ways to establish trees on tough sites. This work is part of an ongoing research partnership between the City of Saint Paul – Forestry Unit and the Department of Horticultural Science at the University of Minnesota.
by Chad Giblin

The Winter: Dog Park


Many of my friends assume that I am out of the job now that the snow has fallen, and the days are short and cold. Although we don’t get outside as much anymore, there is still a lot of work for team tree over the winter months. Recently, we drove out to St. Paul to take data on the High Bridge dog park. There is an earlier article that talks about the dog park in more detail, but it is basically a remidation site where we planted groups of 1 1/2″ caliper trees on the site of a former rail yard for a coal plant. The site is a difficult place for trees, with poor soil conditions, and of course, lots of dogs, who may or may not be nice to the trees we planted. We have been taking data for awhile on how well they are growing to see what varieties do well in the adverse conditions.

During our check up on the trees, we were going to collect data on caliper and take photos of the trees.  Sadly, many of the trees have lost all their cambium at some points, which will most likely kill the trees. Chad said that when he originally checked the site out, the trees in the surrounding area showed signs of damage from critters, and there was probably a lot of them living in the area.

PC181017.JPGThe remaining trees that survive the winter will make it to the 2″ caliper mark, where the bark usually will become hard and inedible. Also, there was generally less damage on Catalpa, Birch, and Alder than other varieties. 

Team Tree met up with some Saint Paul Forestry after our initial visit and wrapped the stems, so some of the trees will make it to spring!

Turning Brown to Green – The Phalen Brownfield

Across the United States there are pockets of land in our urban environments that have been made inhospitable for the growth of most trees and other desirable plants.

These areas, while once comprised of native soil and vegetation, have become “brownfields”, generally only supporting less desirable plants like thistle, nutsedge, knotweed, and crabgrass.

Brownfields are generally created over a long period of time by various human activities (construction, development, chemical pollutants, etc.).  The soil in this are is altered in such a way that many trees have a difficult time establishing.  These sites are used by urban foresters to identify tree species and varieties that will adapt to even the harshest of urban conditions. 

The following map (created with ArcGIS) gives an overview of the recently planted brownfield site in Saint Paul.  Located on the southwest corner of Phalen Blvd. and Payne Ave., this site is a collaborative research project between the Saint Paul Park & Recreation’s Forestry Division and the University of Minnesota’s Urban Forestry Research and Outreach Nursery

Phalen BLVD 2010 Tree Planting - Initial Inventory June.jpgPayne-Phalen Site.JPG


Many of the species planted at this site are of interest in other areas of Saint Paul and Minneapolis, representing possible replacements for threatened trees like ash. 

Others are tried-and-true species that have worked on other locations but never put to the test in a place like this!

If trees survive (and thrive!) in this location they become prime candidates for use throughout the city, especially on tough disturbed sites.

Watch this site for updates as the project progresses!

Payne-Phalen Crew.JPG


by Chad Giblin