A tree grate is sort of metal cage that is designed to protect the roots and trunks of trees growing in urban areas, particularly in settings dominated by concrete. Grates keep tree bases out of sight, and help planting plots stay level with sidewalks, roads, and any surrounding terrain. In this way, trees can be seamlessly integrated into a variety of settings without concern over concrete buckling or drainage issues.
Trees are generally desirable in urban environments, but integrating them can be tricky. In parks and open spaces, there is usually no problem in letting a tree run wild. On more narrow passageways or congested pedestrian corridors, however, the uneven nature of tree bases, often made of dirt and gnarled roots, can be hazardous. Tree roots also tend to store water, making them a sure bet for puddles and muddy conditions on rainy days. A tree grate solves these problems by protecting the tree’s base, while still allowing it the plant to thrive.
Most of the time, a tree grate is a pre-planned part of landscape development. It is sometimes possible to install a grate into an existing road or sidewalk, but this is often very costly and time consuming. Civil engineers and city planners intending to integrate trees into urban landscapes usually start by planting, then pour sidewalks or roadways around those designated plots. Once everything is set, tree grates are fitted around each trunk, creating but one flush plane.
Aside from aesthetics and pedestrian safety, tree drainage is another major reason planners install grates. Most of the time, there is a substantial clearance between the soil at the base of the tree and the top of the grate. This open area is a perfect place for water runoff to collect. A tree with a tree grate is able to collect all of the moisture it needs without allowing water to pool on the passageway above.
In many cases, a grate proves one of the most innovative drainage solutions for wet areas. When properly placed, a grate can serve as a water run-off depository. It will not only catch rain, but can also actively drain the sidewalk and nearby thruways of standing water.
A tree grate can also help with weed suppression, and largely reduces the need for continued landscape design. Arborists may be periodically called in to check on tree health, and may do routine trimmings and branch removals. Little more is ever required, however. The grate protects not only the host tree, but also the soil beneath, eliminating the need for ground-level care in most cases.
Most grates are custom-made to fit within a specific environment, though certain standard sizes are often available. The least expensive grates are usually made of steel and are square-shaped. This allows for easy integration into surrounding concrete or otherwise rigid environments. More decorative grates can be round or custom-shaped. Designer tree grates are not often any more expensive to manufacture, but can be much more costly to install, and usually also command a separate “design price."
Materials are one of the biggest factors in tree grate price. Steel and metal composites are usually the cheapest, while cast iron, wrought iron, and other heavy metals can be quite expensive. Different metals lend different looks, and planners usually consider several options before deciding on what would be best for any given space.