Greening schoolyards: is planting a few trees really enough?
All over Belgium, projects to green schoolyards are multiplying. This is excellent news. But behind this enthusiasm, a question deserves to be asked frankly: what are we really trying to transform?
Planting a few trees is not always enough to rethink a space. The real issue is often deeper than the gesture.
Why schoolyards need to evolve
Many schools today remain heavily paved : concrete, asphalt, impermeable surfaces, direct exposure to the sun without any protection. These spaces quickly accumulate heat and offer almost no ecological function. During heatwaves, some yards exceed the temperature of nearby shaded areas by 10 to 15°C, a gap documented in several studies on urban heat islands.
The issues are now well identified: reducing these heat islands, improving water infiltration rather than sending it back to the sewers, introducing biodiversity into areas that are largely devoid of it today, creating living educational spaces. And more simply: improving the daily comfort of students, who spend a significant part of their day in these spaces.
Benefits that go far beyond ecology
Greening, when seriously considered, transforms several dimensions simultaneously.
In terms of climate : more shade, measurable decrease in local temperatures, reduction of direct radiation reflected by mineral surfaces.
On the ecological level : return of pollinating insects, plant diversification, increase in living surfaces capable of infiltrating water and hosting microfauna.
On the educational level : daily observation of life, permanent and free educational support, awareness that no longer depends on a one-time school trip but becomes a constant presence.
A properly vegetated courtyard then becomes much more than a recreational space. It becomes an educational tool, a local climate regulator, and a refuge for biodiversity — often the only one in the immediate vicinity in dense urban areas.
Beware of simplistic answers
Not all greening projects are equal. This is the point that communication around these projects often forgets.
Planting a few raised beds or installing three isolated trees on asphalt does not transform the overall functioning of the place. In many cases, it remains a cosmetic gesture. Symbolically useful, but it does not change the thermal balance, the water cycle, or the capacity to host biodiversity.
A few questions can help distinguish a truly transformative project from a green facade:
Is the soil alive, or just covered with imported soil on compacted asphalt? Can water infiltrate naturally, or does it always run off to the drains? Are the chosen species suited to the local climate and capable of establishing themselves sustainably, or is it a decorative assortment that will require constant watering? And above all: how will this space evolve in ten years, who maintains it, who thinks about it in the long term?
These questions are not trivial. They determine whether the project closes an ecological cycle or simply adds another maintenance expense to a space that remains, fundamentally, mineral.
The real question
The question is not "how to green a courtyard?".
The real question is: how to design a school space capable of sustainably accommodating more life?
The nuance is important. The first question calls for a technical and specific answer: plants, containers, a budget. The second calls for a systemic reflection: soil, water, biodiversity, use, duration.
Greening is often just a starting point. What follows matters more than the initial gesture.
Understand before transforming.