Growing city populations and limited space are driving the adoption of green roofs and green walls covered with living plants. As well as boosting biodiversity, green roofs could play another unexpectedly valuable role by increasing the electricity output of solar panels.
Beware that the problem with rooftop greenery is that a lot of building’s ceilings aren’t strong enough for massive soil.
So either the soil has to be very thin, or it often isn’t practical. Keep that in mind.