Earth Day: Städte zum Blühen bringen für mehr Biodiversität

Urban biodiversity can become a refuge

We often imagine the countryside as the natural sanctuary of biodiversity, and the city as its opposite. Yet reality is more nuanced. In Geneva, as in other Swiss cities, biodiversity can locally exceed that of intensive agricultural areas. Large-scale farming has simplified landscapes: monocultures, uprooted hedges, early mowing, pesticides, and the homogenization of habitats. Production has increased, but floral diversity has declined.

The city works differently. It brings together public parks, private gardens, wastelands, rows of trees, planted terraces, and varied ornamental plantings. This mosaic creates a succession of blooms spread across time. Some native species find refuge there, sometimes even more than in agricultural plains. Urban biodiversity can be greater than that of countryside areas dominated by monocultures.

On Earth Day, this reflection takes on particular resonance: what if protecting biodiversity simply began with rethinking our urban spaces?

The city can therefore become a refuge.

But a refuge does not mean an unlimited resource.

Photo credit: FreeTheBees

Too many domestic bees in the same place?

Faced with this relative richness, one reflex has emerged in recent years: installing beehives in cities to “help the bees.” In Geneva, urban colonies have multiplied. Companies, schools, and private individuals want to get involved. The intention is sincere, often generous. The problem does not lie in the hive itself. It lies in density.

In a natural environment, one generally observes between one and five honeybee colonies per square kilometre. In an apicultural context, this density can be far exceeded. Yet the honeybee (Apis mellifera) is a highly efficient generalist species. When a large number of colonies are concentrated in a limited space, competition for nectar and pollen inevitably intensifies. This pressure does not only affect domestic colonies among themselves. It also affects wild bees.

In Switzerland, nearly 600 species of wild bees coexist. Many are specialized on certain plants or specific habitats. They do not live in colonies, do not produce honey, and have narrower margins of adaptation. Collected data indicate that 10% of wild species have already been eradicated and 45% are threatened. When the density of domestic bees increases sharply in a restricted urban space, competition for resources can disadvantage these already fragile species. Added to this is an increased risk of transmitting parasites and pathogens when colonies are concentrated.

The paradox then becomes clear: the question is not whether there are enough bees, but whether there are too many domestic bees in the same place.

In Geneva, the priority should be more flowers, not more hives

Geneva is a constrained territory. Wedged between the lake, borders, and urbanized areas, the truly available surface is limited. Adding hives does not increase the quantity of flowers. It simply divides existing resources among more colonies. In this context, multiplying hives does not necessarily strengthen biodiversity; on the contrary, it may increase pressure on an already delicate system. This is not simply a problem specific to Geneva, but the case for the vast majority of cities.

If the objective is truly ecological, the priority should therefore not be to increase the number of hives, but to increase the territory’s carrying capacity. This means diversifying and extending native floral resources, encouraging blooms from spring through autumn, reducing systematic mowing, and restoring local hedgerows. It also means preserving habitats: keeping hollow trees, leaving dead wood, and maintaining areas of bare ground for ground-nesting species. Wild bees need varied habitats before they need hives.

The answer may not lie in more hives, but in more flowers.

Let Geneva bloom. Let our neighbourhoods bloom. Let those spaces we pass through without seeing them bloom.

So many small green spaces are now left abandoned or maintained in a uniform way, mown too short and stripped of their ecological potential. Yet these places could become true reservoirs of biodiversity.

An embankment at the foot of a building; A grassy strip along a pavement;

A roundabout; An inner courtyard; A flat rooftop;

Every planted surface is an opportunity.

Transforming these spaces into native wildflower meadows, diversifying plantings, and allowing certain areas to evolve more freely is a profoundly “win-win” approach. A win for biodiversity, which regains food sources and habitats. A win for residents, who benefit from a setting that is more alive, more colourful, and more soothing.

The vision supported by FreeTheBees

From this perspective, supporting initiatives that restore living space, rather than simply increasing colony density, becomes coherent. This is precisely the spirit behind the vision supported by FreeTheBees: giving nature its place back, recreating the conditions for balance rather than compensating for imbalance.

A city in bloom is a more beautiful city. But above all, a more resilient city.

And sometimes, this commitment can also be worn close to oneself. As a discreet reminder of what one chooses to support: more flowers, more life, more balance.