Many Americans are searching for things that they can do to improve their environment, such as participating in community cleanups and driving more efficient cars. One great thing that almost any homeowner can do to make a big difference is to plant a rain garden. Rain gardens naturally absorb and filter large amounts of rainwater during storms that would otherwise turn into runoff, causing pollution and flooding downstream and depleting the local water table. A well-designed rain garden can increase absorption by up to thirty percent.
Basically any low-lying area that tends to collect water during heavy rain and has been planted with plants chosen for their ability to thrive in such conditions is a rain garden. Planting a rain garden can be as simple as planting the areas of your landscape that already tend to collect water in heavy rains with better-adapted plants, or it can be something big enough to require landscape designers and serious construction. For most homeowners the best solution will likely be something between the extremes. Any rain garden, though, is better than nothing. Every ounce of rainwater that is naturally filtered and reabsorbed into the local water table helps to ensure a healthy, plentiful local water supply as well as protecting the environment downstream from flooding and pollution.
There are four main things that the most successful rain gardens all have:
1. A low-lying area that fills with water during storms and holds it long enough to be absorbed effectively
2. Plants chosen for their ability to thrive in intermittent flooding and drought, absorbing and retaining water in storm conditions
3. Loose soil that will effectively absorb storm overflow and transmit it into the water table
4. Mulch which will absorb water and provide natural nutrients to the plants
You most likely already know the best part of your landscape for collecting water, and you probably consider it a problem area. Those places are usually the best for starting a rain garden, especially if runoff from your roof and lawn drain into the area (the most free-flowing and polluted water on most landscapes). A rain garden should be planted at least ten feet away from any buildings to prevent the excess water from damaging the foundation. To prepare the area, dig to around two feet deep and loosen the soil, adding lighter soil or sand if your soil is very dense or clay-like. This process will give you excess dirt, which can be simply moved away or used to raise the area surrounding your rain garden to capture even more water.
There are lots of plants that are perfect for rain gardens: not only well-adapted to alternating standing water and drought, but also attractive. Japanese Iris, Aster, Calla Lilies, and Cannas are all staples of rain gardens. When considering other plants for your rain garden, I recommend using native plants when possible, as they are often more readily adaptable to local conditions.
Good mulch serves several uses in your rain garden. It prevents erosion, which is a big concern in an area exposed to large amounts of rainwater. It also helps to seal the moisture into the ground, allowing it time to enter the water table. Mulch also helps to keep your rain garden low-maintenance by discouraging weeds and providing natural organic nutrients as it decomposes. A thick layer (a couple of inches) of a heavy organic mulch is optimal. You’ll want to choose something coarse that will not float as easily as wood chips or shreds. Do not use grass clippings as mulch in a rain garden, as they produce too much fertilizer and could damage your plants.
Taking these four things into account should do well for a small, simple rain garden. For larger gardens you’ll certainly want to do more research, and maybe hire a professional to help you. As with most gardening and landscaping projects, help can usually be found at university extension offices or gardening clubs.
Thomas Andrews is a garden writer for the Park Seed Company and the Park Seed Garden Journal. One of America’s largest direct-marketing horticulture companies, Park Seed has maintained its dedication to the American family garden for 140 years. Park Seed is proud to bring gardeners thousands of high-quality seed, plant, bulb, and garden supply choices.
Source: Thomas Andrews