How to create a roof garden?
Making a roof garden requires special skill and materials.
The first thing to do is lay a drainage layer over the terrace floor. We use volcanic red lapilli with a grain size of 11/14 mm for a minimum thickness of 10cm. Thanks to its porosity, it drains excess water and retains a reserve, making it available over time. By doing this, we prevent water stagnation on the terrace, which is essentially a large container.
On top of the Lapilli, an anti-root sheeting can be placed, to maximize drainage without root intrusion.
Now we lay the fertile layer on which the plants will sit. Firstly, a soil must be used to ensure proper root drainage and oxygenation over time. This is crucial. Traditional soils tend to break down and compact themselves, leading to the onset of fungal diseases and root asphyxia.
Agricola 2000’s Soil for Roof Gardens uses inert volcanic materials, which, combined with a blend of Blond Peat, ensure a stable environment thanks to its porosity, lightness and immutability over time, making it ideal for root development, whether you’re sowing grass or planting flower, shrub or trees.
The thickness of the fertile layer varies depending on the type of plant species. It should be at least 15cm for turf and up to 60cm or more for shrubs or trees.
If you want both shrubs/trees and turf, you need to lay a 5-10cm layer of Soil for Turf over the Soil for Roof Gardens. The volcanic sands and blond peat lend themselves to an easy and smooth installation. Sow and plant lightly, then roll to get a perfectly level lawn.