German cities roll out tree‑watering schemes to combat heat stress

In Überlingen on Lake Constance, the municipality installs underground tree pods with specially formulated substrates that retain water and release it slowly, places water‑filled plastic bags around young trees for deep irrigation, and equips selected sites with moisture sensors to target watering needs.

Karlsruhe’s garden office launched a volunteer programme that hands out free watering cans to residents who agree to regularly water street trees, a move that quickly filled its initial supply of 50 cans.

City officials stress that such heat‑mitigation measures are essential public services but face financing gaps, with municipal climate‑adaptation funding still limited despite a federal special fund for infrastructure and climate neutrality.