Does anyone know anything about gardening?

The client brief for this small, narrow garden of a terraced property
in north east London was for greater privacy whilst retaining an area
large enough for hosting guests. At the core of the design process was
sustainability.

All the finishing material and soil, apart from the lightweight soil
for the green roof on the shed, was either recycled or from the site.
Water recycling was also part of the sustainable design. The green
roof acts as a water harvester, connecting to the tallest raised
planter to help irrigation. Water is also harvested from the house
roof to form a water feature, counter-levered to the eastern boundary
fence line and connecting directly into the pond from which the
overflow is connected to the lower bog garden raised planter. The
raised planters create interesting levels and screening, framing the
main seating area to the back of the garden. The fencing utilises
different timbers and sizes to create a staccato effect for added
interest and contrast. The tropical planting scheme softens the hard
landscape elements and provides year-round privacy.

https://www.baliawards.co.uk/environmental-impact-best-use-of-recylced-materials