Choosing to go green by installing a rain garden is a choice for clean water, reduced resource use, and healthy habitat. Rain gardens reduce run-off and create a beautiful landscape feature. These benefits, however, rely on seasonal maintenance. Simple, proactive steps ensure that a rain garden functions properly and benefits the landscape.
Erosion is a consideration as rainwater or snowmelt moves through the rain garden inflow. Deep-rooting native plants and the inclusion of shredded, hardwood mulch prevent erosion by physically slowing water flow, stabilizing soil, assisting with water infiltration and moisture retention, and limiting weed growth. Thoughtful placement of 6- to 12-inch boulders can also absorb the force of water and add a distinctive feature to a rain garden.
Consideration should be given to new plants versus mature plants. Young plants are more susceptible to failure from both dry and wet conditions. Large, established plants tolerate drought and saturation. New plants should receive 1 inch of water per week, easily measured by placing an empty tuna can in the rain garden while watering. During subsequent growing seasons, plants have established root systems and only need supplemental watering during excessively dry periods or if species prefer consistent moisture. If an extended rainy period follows a rain garden installation, cut a temporary notch in the outlet berm.Â
The removal of debris and sediment that is carried into the rain garden with inflow will prevent ponding. This issue is likely if the rain garden is adjacent to a road or driveway and receives meltwater in the spring.
As with any garden, weeding is necessary to maintain aesthetics and limit competition. Desirable plants that become dominant can be split or their seed collected and sown in other areas of the landscape. Timely pruning and the removal of last year’s growth from grasses and perennials will also provide a maintained appearance.