What Is a Rain Garden?
A rain garden is a new, popular technique of building a garden bed in a
low area that accumulates water during and after a storm. The garden is
usually planted with native plants accustomed to damp to wet conditions.
Rain gardens help collect and filter rain water and allow it to seep
naturally into the ground. This helps to reduce or slow down the amount
of rain water runoff reaching our storm drains, retention areas and
streams. A rain garden is shaped like a shallow bowl, with a depression
in or near the middle to hold rain water. The depth of the depression
can range from 2 to 6 inches if you do not want standing water or up to
18 inches if you want a pond-like garden. The depression should also
have gently sloping sides so the plants can take hold. The rain garden
can be planted and maintained like a formal garden, or can have a more
People can replace existing flower beds with rain gardens. You need to reshape the landscape to retain water in the garden bed, and replace your existing plants with those that are better suited to the wet conditions rain gardens periodically experience. Native, flood tolerant plants are recommended. They are well adapted to periodic flooding, and can tolerate the wide range of temperatures and water conditions we experience in Itasca.
Suitable Plants for a Rain Garden
Plant selection should be based, in part, on the amount of sunlight your garden area will get. Some plants require full sun, others partial sun, and some are very shade tolerant. You can also select your plants by flower color, blooming season, height and foliage. A well designed rain garden provides color throughout the growing season and is an attractive element to your yard.
Suitable Garden Locations
gardens should be located in an area that rain already drains to, or an
area down slope from your downspouts or sump pump outlet. It should
slope away from your house, so overflow will not flood near the
foundation. A well designed rain garden will reduce flooding, help
absorb nutrients and other pollutants and help keep our streams, ponds
and lakes cleaner and healthier. Water Collection
During a storm, rain water collects in the rain garden. If it is a minor storm, the rain garden should not overflow, capturing all of the water during and immediately after the storm. Over the next 1 to 2 days, the plants help the water soak into the ground, so that the garden area quickly becomes dry.
Concerns About Mosquito Breeding
People are often concerned about creating a mosquito breeding site. If you are creating a rain garden in an area that is already wet during and after rain storms, you can actually eliminate mosquito breeding sites by planting the rain garden. Rain garden plants have very deep roots that allow water to soak deep into the soil. They also are very well adapted to growing in wet conditions and through plant processes, quickly absorb more water than a mowed lawn.
For more information, please visit the Conservation Foundation website.