Sustainable practices for landscape design: rain gardens
We generally think that building in a sustainable way, is about the buildings itself. But many times we can contribute to bring down energy consumption, solar heat gaining, sun radiation, and save some water, by implementing some well known practices in our gardens. I am going to concentrate this time on rain gardens, vegetated swales and natural pools. I started to think about the importance of the correct sustainable landscape practices, as I talked to my canadian client on possible strategies for an Eco-home.
A rain garden is nothing more than a depression in your yard planted with native plants that collects water run-off from your roof, driveway or other hard surfaces. It acts as an infiltration system that keeps our water out of the storm water system and on our properties, re-charging the ground water. Rain gardens reduce the amount of storm water that ends up in our streams and lakes, and helps to improve water quality by filtering through plants and the soil. Developing a rain garden gives us the opportunity to keep our water clean and percolate through the soils. Rain gardens are very used in parking lots, for example.
Developing a rain garden is an easy enough task. You want to choose the location carefully so you get the most benefit of a rain garden. Look for a low depression or low lying area that already exists in your yard. If you don’t have a low spot, you can create one by digging a depression in your yard where water would naturally collect, or you can run your downspouts directly into your rain garden area.
Mix some compost into the existing soil. Remember the purpose is to filter water, so you want your soil to be good for plants so filtering can occur. A heavy clay soil will hold too much water, not allowing it to percolate into the soil, so be sure you know your soil type and add necessary amendments.
When an area’s soils are not permeable enough to allow water to drain and filter properly, the soil should be replaced. This mixture should typically contain 60% sand, 20% compost, and 20% topsoil.
Plants selected for use in a rain garden should tolerate both saturated and dry soil. Using native plants is generally encouraged, since they don’t need to be watered. This way the rain garden may contribute to urban habitats for native butterflies, birds, and beneficial insects.
Well planned plantings require minimal maintenance to survive, and are compatible with adjacent land use.
Plant selection depends also on where you’re located in Costa Rica, so don’t hesitate on asking me what are the correct plants for your location!