Turn on the Home and Garden channel or visit newer parks and botanical centers and you are bound to hear about a rain garden. Landscapers, homeowners and conservationists are all catching on to rain gardens and spreading the word about what they do and how to build one. While planning and creating your own rain garden may seem like a daunting task, we’re here to answer some questions!
- What is a rain garden and why is it important? A rain garden is a landscaped area planted with wild flowers and other native vegetation that soak up rain runoff from roofs, driveways or yards. Asphalt and cement are replacing green spaces all around us, causing an increase in stormwater runoff. This raises flooding risks, carries more pollutants from streets and parking lots into local streams and lakes and requires more rigorous treatment at your water works plant. Compared to a regular patch of grass in your lawn, a rain garden allows about 30% more rainwater to soak into the ground, where it is naturally filtered and doesn’t carry all the oils and grime from pavement into the water supply.
- How does a rain garden work? A rain garden is actually planted lower than the surrounding ground, to encourage the water to gather in it. It won’t form a pond, although water does pool in the garden during rainfall. The water will be absorbed by the vegetation in the garden, with excess filtering into the ground, and will be dry between rainfalls.
- Where should a rain garden go? Placement is important to avoid major problems down the road. Make sure it is built at least 10 feet from the house so the water doesn’t seep into the foundation, and do not place it directly over a septic system. Build it in a spot in the yard that gets full or partial sun, but not in a part of the yard where water already ponds. If water is gathering in a certain spot, that means the ground isn’t soaking up the water well, and the purpose of this type of garden is to encourage good infiltration. A rain garden must be located so runoff moves to it, so it’s important to get out in your yard during rainfall to see how the water moves before you actually start digging.
- Is a rain garden high maintenance and expensive? Once the plants are established, maintaining the garden should be pretty simple. During the first two years, weeding and watering will be needed and you may need to thin vegetation in later years when the plants mature. Building a rain garden doesn’t have to be expensive. Recruit family members and friends to help provide the labor. You can also minimize the cost of purchasing plants if you use native foliage that might already exist in your yard or a neighbor’s yard – but be sure to ask before you start digging up someone else’s greenery!
Iowa receives anywhere from 28-36 inches of rain each year, and a paved half-acre lot will runoff over 434,000 gallons of rainwater each year. This water inundates our storm drains with polluted water full of heavy metals, sediment, floating garbage and litter, hydrocarbons, bacteria, and grass clippings. This storm water runoff floods into local water sources without any treatment and cause degradation of raw water quality. By doing a little smart landscaping in your yard – and hopefully encouraging your neighbors to do the same – you can reduce the amount of polluted runoff that degrades water quality and reduce flooding in your neighborhood while making your yard look beautiful!