Product Spotlight: Silva Cells
Recently, the crews at E-Landscape completed work on the landscaping for the new Spa Gate townhomes in Annapolis. This project, for Carraway Homes, utilized Silva Cells, a great product that promotes tree growth in high traffic urban areas.
Silva Cells solve several ecological problems posed by commercial and urban landscape development, by controlling storm water and allowing healthy tree growth. They are modular components that open up the space under pavement, allowing room for tree root growth. Each cell is composed of a frame and a deck. The frame is composed of six vertical posts which protrude from a rectangular base. These support the horizontal deck, a mesh platform with plenty of room for air and moisture to circulate in developed environments. The cells compose an underground cubical framework set beneath load-bearing paved spaces. The Silva Cell’s design meets H-20 loading standards which allows for a truck’s axial load of up to 32,000 pounds. The structural framework can therefore be placed under most foot or vehicle traffic areas, while still allowing trees to grow unhindered beneath paved surfaces.
Trees and plants are critical to the healthy movement of water through a landscape due to a process known as evapotranspiration. This term describes the amount of water evaporated directly from the soil and through plant surfaces (transpiration), such as tree leaves. Evapotranspiration is one major method of controlling storm water retention in the soil, and it is a critical factor in the overall water circulation of a given landscape’s ecology.
Silva cells help filter pollution from developed landscapes in a more ecologically friendly manner. Normal water circulation can be hindered by commercial or urban development, which causes extensive runoff, compacts soil, and prevents the movement of water through the earth. Normally, soil and vegetation filter pollutants by transporting and filtering storm water. Without proper drainage, storm water’s pollutants transport off-site through urban drainage systems, which is a major cause of urban pollution.
By expanding the empty space deeper in the soil, Silva Cells aid tree root growth. Normal root expansion is hindered by a lack of access to uncompacted soil. Tree roots tend to follow what are known as oxygen-rich macropores during their growth into the soil. In other words, they seek out soil with a lot of oxygen and space. The Silva Cell structure has 92% void space, and its rigid framework can reach up to 4 feet deep. Studies have shown that tree roots can grow very deep indeed, so the Silva Cell provides ample room for the tree roots to develop in a more normal growth pattern. This extra room for expansion provides the added benefit that roots, no longer seeking oxygen near the surface, stop pushing up paved surfaces, which can be a costly hazard to repair.
With all these benefits, it is easy to see why the Silva Cell has become so widely used. They have become a vital aid to storm water control and the overall healthy ecology of urban and commercial landscapes.
The next time you visit Maryland Hall for the Creative Arts, you’ll likely pass right by the new Spa Gate townhomes. Now you know what lies below the surface of the ground that is making the land around the townhomes more suitable for tree growth!
