Leaf Piles for Biodiversity

At dozens of locations throughout the city of Winterthur, Stadtgrün is leaving additional piles of leaves on the ground starting this autumn. The leaf piles provide shelter for small animals and thus help preserve biodiversity.

The measure is part of Stadtgrün’s ecology and biodiversity promotion initiative and is set out in the new “Leaf Management” concept. The aim is to transport away as little leaf material as possible and to carry out as much work by hand as possible.

New Leaf Piles Promote Biodiversity

For years, Stadtgrün has been leaving leaves on flower beds, under shrubs and around trees — where possible in the form of piles. As part of its ecology and biodiversity promotion initiative, Stadtgrün is now stepping up its efforts to preserve biodiversity through leaf management. To this end, Stadtgrün has designated dozens of additional spots on green spaces across the city where leaves are left in piles.

The piles serve as shelter or foraging sites especially for hedgehogs, but also for other wildlife such as slow worms, toads, frogs, lizards, shrews, spiders and insects. The inside of a leaf pile is warmer due to the decomposition process. It also provides protection at a time of year when retreat sites are scarce because shrubs and trees have shed their leaves.

Stadtgrün staff encourage owners of private or corporate gardens to also leave leaf piles wherever possible. An out-of-the-way, sunny spot is ideal. To prevent the wind from scattering the piles, they can be secured with branches and deadwood.

Leaves as Climate Adaptation and Nutrient Source

Leaves on flower beds, under shrubs or around frost-sensitive plants also provide good winter protection. Leaves also help retain moisture in the soil for longer and supply plants with nutrients as they decompose. Thus, leaves not only help preserve biodiversity — they also help us better meet the challenges of climate change.

The leaf concept fundamentally governs how fallen leaves are handled. Leaves are removed from lawns and pathways to protect the historic park grounds. Wherever possible, Stadtgrün staff carry out this work by hand. Leaf blowers are only used when they are significantly more efficient and effective. Where possible, the leaves are also used on-site — for example, to insulate the fountains at the Stadthaus or in the Stadtgarten. If this is not possible, the leaves are either composted by Stadtgrün on the cemetery grounds or by third parties at a biomass facility. The resulting compost is largely reused by Stadtgrün to fertilize its own green spaces.