KarunaNews Story

After a general assessment of street traffic in Stockholm in 2001 that concluded that two-thirds of trees in the city center were dead or dying, Björn Embrén, a former professional gardener, became Stockholm’s first “tree officer” and concocted the “Stockholm tree pit” model. This involves digging a pit and constructing a frame underground around the tree’s roots, and then filling said pit with a mixture of soil and stone to both aerate and fertilize the soil. Proponents say the method has a number of benefits, including the fact that pits can be installed around existing trees, can bear the weight of heavy-vehicle traffic, require little topsoil and need less watering than traditionally-planted trees. The technique has proven so successful that it has become the standard for all other development projects in the public spaces of Stockholm. Britt-Marie Alvem, one of three current tree officers, estimates that the city now builds between 500 and 1,000 tree pits a year.