Brussels trees to send a signal when they need watering

The Brussels region is planning to equip all 32,000 of its trees with a sensor and microchip that will communicate when the tree needs watering.

The smart technology is first being added to the region's youngest and most vulnerable trees, and aims in the long term to allow for more efficient use of water.

The sensor is buried in the soil. "Based on previously entered data, such as the tree species and the composition of the soil, the chip informs us via an app when a tree needs extra water," said Brussels mobility minister Elke Van Den Brandt.

"This way we do not waste water when it is not necessary, especially in periods of long drought."

Until now, a tanker has regularly travelled around the region's roads and green spaces, watering the roots of young trees whether they were thirsty or not.

"Maintaining and watering 32,000 trees in the summer is an immense job," said a Brussels Mobility spokeswoman. "The intention is to eventually provide all of them with a sensor with chip, but we are starting with the young trees, because they are the most vulnerable."

So far, Brussels has invested €200,000 in the operation, which will be offset by reduced water costs and reduced damage.

Tree doctor Wouter Crucke explained: "Dry roots are the main cause of trees collapsing in their first years of life. A young tree needs at least 100 to 200 litres of water per week to develop properly.

"It will not get that much water from rain alone, certainly not in dry periods and certainly not in large cities, where a lot of water washes away in the sewers."