Mulching is a gardening practice not widely used in urban green spaces, but it can play a crucial role in creating healthier and more resilient landscapes. A layer of organic material (such as wood chips, leaves, or bark) helps the soil retain moisture, regulate temperature, and reduce the need for irrigation. At the same time, it suppresses weed growth, lowers maintenance costs, and enriches the soil as it decomposes. These factors are particularly important in cities, where trees face stress from heat, drought, and compacted soils.

Scientific studies have demonstrated that healthy urban trees deliver a large amount of ecosystem services, from cooling the air to improving well-being. But how does the way we manage trees affect the extent of these services? The Life Urbangreen project set out to answer this question by comparing traditional practices with optimized ones. One of the pilot treatments was mulching, applied as a 5–10 cm layer of organic material in a one-meter ring around the tree collar.

Correct execution is crucial: “volcano mulching”, i.e. an excessive accumulation of mulch around the tree collar, is a serious problem. The trapped humidity creates an ideal environment for fungi and bacteria, leading to collar and root rot. The collar must always remain visible and free.

Mulching was just one of the practices we tested. In the next posts, we’ll explore pruning, grass management, and more before revealing what we discovered!