Design of the planting pit
In recent years attention has shifted to the quality and quantity of planting pits since it became clear that planting a tree in the ground without adjustments is often not successful. The tree will not reach its maximum theoretical age and the intended final image cannot be achieved in the foreseeable time frame. Planting and maintenance therefore result in disinvestments. Topics to consider during the design of the planting pit are the steady availability of water and nutrients and the amount of space for root growth.
In open-spaced urban areas with natural soil, it is usually relatively easy to create adequate rooting space. At tree-sites surrounded by pavement more effort is required to achieve a compromise between rooting space and a stable foundation to prevent deformation of paving. Materials like treesand, structural tree-soil or tree bunkers with a natural soil provide a solution. Each solution has its own characteristics and is applied under different circumstances, from footpaths to locations with heavy traffic load. At the moment possibilities for tree-pit design and application are unlimited, taking into account durability, reusability of the system, budget and maintenance.