By Brian Sullivan, Landscape Designer, Dundee Nursery and Landscaping
You may have heard about a recent trend in landscape design that incorporates rain gardens as an element in the landscape. Rain gardens are shallow depressions that are designed to capture rainwater runoff from the yard and impervious areas such as your driveway and roof. The rain garden acts as a filter, capturing contaminates and fertilizers from these surfaces before they enter our streams and lakes. Rain gardens also reduce the speed with which water leaves the property. Another benefit is increased wildlife habitat.
Rain gardens are planted with perennials and shrubs that filter contaminates and encourage infiltration of water into the soil. Plants are chosen based on the soil types and exposure. Generally rain gardens are planted to look like native systems, but I think that purposeful selection and placement of plants can result in a design that works in settings that range from the formal to rustic. The design of a rain garden can be composed to reflect the surrounding environment and the tastes of the homeowner.
There are several consideration in the design and placement of the rain garden. Rain gardens are generally 3 or 6 inches deep and sized between 7 – 10% of the area that is supplying water. The rain garden will be located in an area where it can capture the water and needs to be far enough away from your home to prevent the intrusion of water into your home. Remember to avoid underground utilities. The basin of the rain garden should be loosened to a depth of 12” to encourage the infiltration of water. Add composted leaf litter and till into bottom of the garden. Shredded hardwood mulch is used to help prevent the evaporation of water and inhibit the growth of weeds.
When designed correctly the rain garden will drain in two days. The rain garden will help in preventing the degradation of our environment, provide additional wildlife habitat, and add some beauty to our lives.
