Berlin Residents Are Adopting Street Trees to Help Them Survive Hot Summers

In Berlin, some residents are taking on an unusual responsibility: caring for individual street trees. As hotter and drier summers put increasing pressure on urban greenery, volunteers are using a digital map to find trees that need water and help keep them alive.

A Tree Named Linda

Among the volunteers is Amanda Gläser-Bligh, who adopted an eight-year-old linden tree outside her home in Charlottenburg. She named the tree “Linda the linden” and carries around 20 litres of water to it each week during the hottest months.

Gläser-Bligh said she noticed that Linda stopped wilting as much after she began watering it regularly.

A Digital Map for City Trees

The effort is organised through Gieß den Kiez, a project whose name means “water your neighbourhood.” The open-source platform maps more than 900,000 trees across Berlin and uses information including tree age, species and rainfall to estimate their watering needs.

Residents can check when a tree was last watered, record their own watering and identify trees that urgently need help. The platform also provides information about watering techniques and nearby water pumps.

Thousands of Volunteers

The project, which began in 2020, now has around 12,000 registered volunteers. Their work complements the efforts of Berlin’s district authorities, which already care for thousands of trees but can struggle to keep up during periods of extreme heat.

Young trees are particularly vulnerable because they have not yet developed deep root systems. Regular watering can give them a better chance of surviving prolonged dry periods.

An Idea Other Cities Can Use

Because Gieß den Kiez is open source, other communities can use its code to create similar systems. Cities including Potsdam, Leipzig and Magdeburg have already developed their own versions, while a district of Paris has also adopted the approach.

For Berlin’s volunteers, the idea is simple: find a tree that needs help, bring some water and look after a small part of the neighbourhood. What began as a digital map has become a community effort connecting people with the trees growing outside their homes.

Sources

• The Guardian — “Like caring for a pet: the open-source tree map inspiring Berliners to water their urban forest,” October 2, 2026.
• CityLAB Berlin — “Gieß den Kiez: Mit aktiver Community und offenen Daten zur Klimastadt Berlin,” September 18, 2026.