Rain Gardens
Rain gardens are becoming more popular as people are becoming more aware of and concerned for the environment. A rain garden is simply a dug-out or naturally shallow depression in the ground designed to catch rain that would otherwise turn into runoff, and with the addition of native plants, a rain garden can be an attractive landscaping feature. Runoff from storm water may come from the roof or other areas within the landscape, such as driveways and walkways. According to studies, up to about 70 percent of streams, lakes, and rivers are polluted with storm water, and much of this polluted water is carried from our yards and gardens. Storm water is filled with pollutants and is not good for the environment. Rain, on the other hand, is a natural source of water that benefits the environment, and it’s always appreciated by plants.
Rain gardens are quite attractive and easy to construct. In fact, anyone can create one. Rain gardens can be constructed in a variety of shapes; however, bowl-shaped rain gardens are the most common. Rain gardens don’t require a lot of space but feel free to create one as large as you like. Implementing a rain garden of any size will make a difference, even if it’s small. Rain gardens, as with nearly any garden design, can be formal or informal depending on your particular gardening style. Rain gardens can easily be added to existing buildings or other structures as well. When designing a rain garden, determine which area of the landscape receives the most rain. During periods of heavy rain, note the runoff patterns and take advantage of any low-lying areas in your yard that may already collect water. Rain gardens can easily be created from these naturally low areas in the yard. However, if there isn’t a low spot in the yard, simply dig one out wherever rainwater flows along your landscape. A rain garden can even be created on a sloped site by designing a small terrace in the slope. The depth of rain gardens vary, from 3-6 inches, and depend mostly on the overall size and location. Personal preference can also play a factor in the depth of rain gardens. Typically, rain gardens shouldn’t be placed right against the house. You should, instead, try to keep the rain garden at least 10 feet away from foundations to prevent problems with potential flooding later. Likewise, try not to place a rain garden over the drainage area of septic tanks.
Place a rain garden in the front yard near a downspout to catch water from the roof. Place it along the walkway or driveway to prevent runoff into these areas. Rain gardens can also be used as barriers between the front lawn and sidewalk or street. You could also choose to tuck your rain garden into waterlogged areas along the outer edges of the yard. Rain gardens along the side or back of the house can capture runoff from the roof as well as minimize mowing tasks by reducing areas of lawn. Backyard rain gardens are usually larger and can be easily integrated with existing gardens by creating dips within the soil that can hold and absorb water. Be sure to provide an adequate outlet away from the home to prevent flooding that may spill into basements. Most properties have an existing drainage pattern that you can use to help alleviate this problem in addition to providing a drain for water overflow.
The soil in your rain garden is important. A rain garden must be able to easily absorb the water that runs off. Therefore, you should determine, beforehand, the type of soil that exists in the area of your rain garden. For instance, soils that are clay-like can become waterlogged easily and may cause problems from too much rain. To avoid this, amend the soil with compost. Adding sand to the soil will help as well. On the other hand, if the soil is too sandy, it will not retain the water, resulting in runoff. Once again, the soil should be worked with organic matter. Define the borders and shape of the rain garden in the chosen site, removing lawn if necessary. Once the soil has been amended, it’s ready for planting.
Ideally, native plants should be chosen for your rain garden; however, there are many non-native plants that will also do well. For instance, daylilies and irises are versatile plants that often do extremely well in rain gardens even though they’re not native to most areas. Plants that are native to an area are better adapted to the particular climatic conditions for that locality. These types of plants also provide local wildlife with familiarity. Plants in rain gardens will thrive easier when they are suited to the existing conditions of the landscape. If the area is shady, for instance, selecting shade-tolerant plants only makes sense. Likewise, if the area receives full sun throughout the day, heat-tolerant plants would be a wiser choice. Where applicable, both trees and shrubs can be placed within rain gardens, provided they do not mind moist conditions. Place them in the center and surround with wildflowers.
Whatever native plants you choose, they should all be suited to both wet and dry conditions. Plants that naturally thrive in wetlands are usually tolerant of moist or well-drained soils; however, those which normally grow in dry areas are not very tolerant of wet conditions. Therefore, if your rain garden consists of well-drained, sandy soil, try to choose plants that are used to drier sites as this type of soil will drain faster, remaining dry most of the time. Alternatively, if your rain garden consists of clay-like soil that is prone to retaining water for longer periods, choose moisture-loving plants that do not mind standing water. Rain gardens can consist of various zones, depending on size and depth, and this, too, should be taken into consideration when selecting plants. For instance, the inner-most area of rain gardens will no doubt be the most saturated; therefore, any plants placed here should be well suited to these conditions. As you move further away, the areas within rain gardens gradually become drier. Plants along the outer edges of your rain garden will help it blend into the landscape. These plants can consist of non-native growers adapted to the conditions of your particular area.
Rain gardens are not costly or difficult to maintain. However, during periods of drought, watering the rain garden may be necessary. A layer of mulch will not only help keep unwanted weeds at bay in the rain garden but will also retain moisture longer. Choose mulch, such as shredded bark, that won’t be as likely to float away.
