Guest Contributor: Cecil Konijnendijk, Nature Based Solutions Institute

With a growing demand for more trees and green spaces in our cities, there is a call for clear guidelines and tools that can help planners and other decisionmakers. Ideally these strategies use the best available scientific evidence on which trees and green space work best in different places. American Forests’ Tree Equity Score is a good example.

Street Trees, Berlin. Photo Cecil Konijnendijk
Trees in Berlin. Photo Cecil Konijnendijk

Research has shown that we need to be able to see trees and other natural elements where we live, work, study and play. Living under urban tree canopies is important for our health and well-being, not in the least because of their cooling effect. We have long known that having easy, proximate access to good green spaces entices us to use these more, thus keeping us active and healthy.

The 3:30:300 rule builds on the latest evidence, calling for us all to be able to see at least three well-established trees from our windows, live in neighbourhoods with no less than thirty percent canopy cover, and have a high-quality green space within three hundred metres (just under three hundred thirty yards) from our homes.

Visualisation of the 3-30-300 Rule. Photo UNECE 2023

Since its launch in February 2021, the 3:30:300 rule has gained wide traction. In the United States, the city of St. Petersburg, Florida was among the first to include it in its urban forestry strategy. In Malmo, Sweden the rule has even made it into the city masterplan. International organizations like the United Nations are now recommending its use.

Implementation of the 3:30:300 rule has resulted in successes, from a new park in an Australian city to new trees being planted in Swedish cities. The hope is that with the motto “trees for threes” the rule will support and strengthen urban forestry programs in New York as well!

New Trees in Malmo, Sweden. Photo Johan Ostberg