The small patches of soil beneath street trees, often overlooked, can significantly enhance biodiversity and help people feel more connected to their neighborhoods. Olivia Besters, a resident of Freiburg, Germany, began tending the soil under a chestnut tree outside her home over 35 years ago. At the time, she wasn’t thinking about biodiversity or environmental issues. “It was the optics,” she explained. The ground was compacted and filled with trash and dog waste. Her main goal was to make the area outside her front door look better. “Everything else came much later,” she said. “Thirty-five years ago, no one talked about climate change or insect decline.” As the years passed, Besters’ small effort grew into a larger movement. What began as one tree bed expanded into 36 across her neighborhood of Herdern. Her dedication to these green spaces has even led her children to gift her a bike trailer for transporting her watering system, and her phone is full of photos of the beautiful flowers that have taken root. Besters has also been nominated for city-wide engagement awards. Her story reflects a growing trend in urban areas where biodiversity is being squeezed into smaller spaces, and people are increasingly disconnected from nature. In Freiburg, a city known for its environmental consciousness, officials noticed residents informally planting and caring for the soil around street trees. In 2004, the city formalized this practice through a program called Baumpatenschaftsprogramm, or tree sponsorship. This initiative helped organize and support what residents like Besters were already doing. In 2010, the city partnered with the Ecostation, an environmental education center, to launch Freiburg blüht auf (Freiburg in bloom). This initiative connected tree bed stewards with ecologists, providing them with seeds, plants, and advice on creating small habitats for native plants and insects. The result has been the creation of “small flowering islands” that help retain soil moisture and provide habitats and food for insects. Research has shown that when residents actively care for these tree beds, it can boost the variety and number of plant species in urban areas. In one study, researchers surveyed 200 street tree beds, comparing 100 that were actively stewarded with 100 that were not. They found that the stewarded beds supported about 1.6 times as many plant species. While these beds had more non-native plants, they also supported more native species and more varied plant communities. Stewards described their work as relaxing, restorative, and meaningful. For Besters, tending her tree beds is “pure relaxation” that feels “good for my soul.” Others, like Shari, a 62-year-old steward, said planting tree beds can “really promote biodiversity” in urban areas that might otherwise be dominated by concrete. Caring for tree beds also helps people connect with their neighbors and the broader community. Stewards often receive positive attention from strangers and encourage others to take up stewardship themselves. Visible care signals that a place is valued, which can lead to more respectful behavior from others. Research has shown that 73% of stewards learned about tree bed care from a neighbor or by seeing someone actively gardening. This suggests that visible gardening practices can spread as people observe and imitate each other. In Freiburg, more than 500 residents now participate in the tree sponsorship program, caring for about 700 tree beds. Around 3% of the city’s 22,000 street trees are stewarded. Expanding this effort could create more habitats for plants and insects and, when strategically placed, help connect larger green spaces. The social impact of these small spaces can also grow quickly, helping people connect with nature, develop a stronger sense of place, and interact with both neighbors and strangers. Because these acts of care are highly visible, they can inspire others to join in, creating more stewardship, more habitat, and more opportunities for nature and social connection.