Grow Your Own Rain Garden
Rain gardens, also called bioretention facilities, are one of a variety of practices designed to treat polluted stormwater runoff. Rain gardens are designed landscape sites that reduce the flow rate, total quantity, and pollutant load of runoff from impervious urban areas like roofs, driveways, walkways, parking lots, and compacted lawn areas. Rain gardens rely on plants and natural or engineered soil medium to retain stormwater and increase the lag time of infiltration, while remediating and filtering pollutants carried by urban runoff. Rain gardens provide a method to reuse and optimize any rain that falls, reducing or avoiding the need for additional irrigation. A benefit of planting rain gardens is the consequential decrease in ambient air and water temperature, a mitigation that is especially effective in urban areas containing an abundance of impervious surfaces that absorb heat in a phenomenon known as the heat-island effect.
HOW TO BUILD A RAIN GARDEN IN YOUR YARD Step 1: Decide on rain garden placement 1. Find out where water is coming from (like your roof or driveway) and where it goes (like a sunken spot in your yard, or the street) after a storm. Your garden should sit somewhere between the two. 2. Ensure the spot is at least 10 feet away from your home, and at least 25 feet away from a septic system. Also, confirm there are no underground utilities in the spot youíve chosen. If youíre not sure, call 811 to find out. 3. Make sure the location gets full or at least partial sunlight. Step 2: Check the soil This step is super important because good soil is what makes or breaks a rain garden. Rain garden soil must be well-draining in order for the garden to do its job. To test your soil: 1. Dig a hole about a foot deep and fill it with water. Ideally, the water should drain within 12 hours, and 24 hours at the absolute most. If it does, you picked a good spotómove on to step 3! 2. If the water didnít drain within a day or less, consider a different location. Soil types can vary quite a bit even within the same yard, so there may be a more suitable spot nearby. Step 3: Choosing plants for rain gardens 1. Your rain garden should be filled with plants native to your region. Do some research to figure out what plants meet that need. For help, you can contact your local county extension officeóthey'll likely have a ready-to-use list of native plants. 2. Select a mix of plants with different colors, heights, and bloom times to add dimension to your garden. Step 4: Size it out 1. Rain gardens are usually sized anywhere from 100 to 300 square feet. To figure out whatís best for your yard, note that a rain garden can typically handle runoff from a surface 3 times its size. So, say your rain garden will be expected to collect runoff from a section of your roof thatís 600 square feet. To accommodate, your rain garden should be about 200 square feet in size. Step 5: Construct your garden With your location, flowers and size figured out, itís time to dig. 1. Use the rope to layout the size and shape of the garden. Most rain gardens are bean-shaped. 2. Dig a flat hole about 4 to 8 inches deep. Make sure the bottom of the garden is leveled. Add compost or sand if needed and work it into the soil. If you arenít adding materials, just till the soil to loosen it up. 3. Add your plants, fill the garden back up with the leftover soil, and mulch the area. Step 6 : Maintenance 1. As with any garden or landscaping, weed and to fertilize as needed. 2. During dry periods it is important to water the rain garden for it to survive and continue its job as a means of stormwater management as well as a habitat for local wildlife.