Green streets

Big healthy trees

Image credit: Niek Roozen

Green character is established quicker with large healthy trees and mature green

Healthy trees planted in a healthy environment contribute to the short term and long term character, value and usability of green spaces, real estate, and the health of surrounding residents. Usability, attractiveness and effectiveness are visible directly following construction and improves as time passes.

Canopy area should be compensated, not the number of trees

Cities should base their tree regulations on the quality of the trees more than on the quantity of trees planted. When mitigating the loss of existing trees (which has a negative effect on air quality), the canopy area of the removed trees should be compensated, not the number of trees.

Large healthy trees have a better survival rate

Trees with a trunk diameter of 30-35cm (measured 1m from the ground) have a better rate of survival because they are more established and less susceptible to growth disturbance such as diseases, molds, bacteria, and wind. Vandalism is less disruptive to trees with a minimum trunk diameter of 20-25cm. The root ball should also be large, compact and contain some fine roots. The costs of replacing dead trees are high when compared to the price of larger specimens.

Trees should be able to adapt to the urban conditions

The suppliers of plant material should be made aware of the eventual conditions in which the trees will need to survive. The production process should include a period of adaptation (transplanting, etc.) so the plants are not shocked when introduced to their new urban environment.

Plant big quality trees and shrubs in urban areas in order to achieve the desired green result directly after realisation.

Tree planting in urban green spaces

The Integrated Planting MethodThe Traditional Forest Thinning Method
Designed by Frits Ruyten and tested in the Prins Bernhardbos in The Netherlands, 1999 and later in other locationsOriginally used in forests planted for wood production
Trees planted: 6-7m height, 2.5 -3m crown widthSmall tree seedlings planted in rows
Trees spaced: 10m or more between treesTree seedlings spaced from 1-5m between trees planted on a grid
Shrubs planted: 1.5-2m height, 1.25-1.50m wide
Shrubs spaced: 5m or more (planted at the location desired when the trees/shrubs reach maturity
Plant costs are high, maintenance costs are lowPlant costs are low, maintenance costs are high (15 years of removing and pruning trees)
Can be used directly after realisationTakes about 15 years to fill and gain a forest or mature park character

Benefits of big trees in green spaces

  • Big healthy trees give a project an instant green character
  • Large healthy trees require less maintenance and have a less chance of dying
  • Larger trees are less susceptible to vandalism

“Scientific and market-conform calculations show that the Integrated Planting Method actually saves money in the long term. The construction costs are two times more expensive than the traditional forest thinning method, but the maintenance costs are actually 60 – 75% lower.”

Dr. Frits Ruyten, landscape architect, Integralis PP



New and existing development

Convince developers of the short term as well as the long term benefits of using big plant material in projects and secure the budget for quality planting and design.