Whenever it rains or snows, the rainwater or the melting snow runs off impervious areas such as driveways and roofs, while collecting the pollutants. Other pollutants are also collected on these hard surfaces, including nutrient-rich yard and pet waste, oil and radiator fluid from automobiles, and other debris and pollutants. The United States Environmental Protection Agency has identified this runoff as a major source of pollution in the US’ waterways. One of the best ways to help to reduce the pollutants is rain gardening and rainscaping. In this article, we gathered important points to consider about these gardens. For local resources and rain garden examples from 6 states, you can check out the official government website.
What is a rain garden?
You can help to reduce the number of pollutants that leave and enter nearby waterways, by building a rain garden. “What is a rain garden?”, you may ask. A depressed area that gathers rainwater from a roof, street, etc., and allows it to ooze into the ground is what we call a rain garden. While it creates colorful and landscaped areas in your yard, this can be an easy and cost-effective way to reduce runoff from your property. Like mentioned before, it can also help to filter out pollutants in runoff while creating a small habitat for birds, butterflies, etc.
Depending on your interests and experience, your rain garden design can be simple or elaborate. Either way, you have to consider:
- garden’s location in the yard
- type of soil you have
- size and shape
- amount of runoff
Choosing the Location for Rain garden
To begin, you have to determine suitable areas for a rain garden of your property. These are usually low places that are kept at a safe distance from other features because;
- water should be kept at least 10 feet (3 meters) away from structures to avoid causing damage to foundations and basements.
- septic system drain fields should be at least 35 feet (10 meters) away.
- the rain garden should at least be 50 feet (15 meters) away from drinking water wells and utility wires.
For professional help, you can call the relevant unit of the municipality to ensure that the underground utilities are not in the way.
Testing the Soil
In sites that are both suitable and close to runoff sources, test the soil. The type of soil you use in your garden is very crucial. To prevent plants from drowning and mosquitoes from multiplying, the soil must be permeable enough to absorb water within 48 hours. This is also the most common time between two rainstorms.
To simply determine a soil’s ability to absorb water, you can do the following:
- Fill a 10-inch-deep, 10-inch-wide (25×25 cm) hole with water.
- The site is suitable for a rain garden if the water evaporates within 48 hours.
- Test the soil at additional prospective rain garden sites on your property if your initial site fails the 48-hour test.
Determining the Size and Shape of the Rain Garden
They can come in a variety of shapes and sizes. The crescent or kidney form is appealing. If you’re putting it between two structures, such as a house and a sidewalk, a long, thin rain garden might be better.
The size of your rain garden is determined by the roof, driveway, or another hard surface that needs to be drained.
Rain gardens typically range in size from 100 to 300 square feet (approximately 10 or 30 square meters).
Runoff from a hard surface that is three times their size will be handled by the gardens. To control runoff from bigger surfaces, many rain gardens may be required. Large rooftops, for instance, may require a rain garden at each downspout.
Choosing Plants For Rain Garden
To make your rain garden project work, you have to choose plants that are appropriate to the soil type in your garden. You can get a soil test to determine that. Also, the plants you choose have to tolerate standing water for up to 48 hours. For more information about rain garden plants, you can also check official articles from the Pennstate Extension and the University of Minnesota Extention.
Plants of various sizes and types aid in stormwater management, so it’s a good idea to plan for a variety of species!
- Rainfall is deflected by trees and huge shrubs, which slows it down before it reaches the ground, allowing it to soak into the soil and not flow off as quickly.
- Tall grasses operate as filters, sucking up water, trapping contaminants, and keeping sediment out of ponds and rivers.
- Plants with shorter, well-established roots hold dirt and direct water into the ground.
According to your soil type, place of the garden, etc., you can find detailed sources for plant ideas online.
Building and Planting
Once the size, shape, location, and plants for the garden have been determined, you can begin the construction.
- To dig, you can lay a rope or hose out in the proper shape to serve as a guide.
- The depth of the rain garden can range between 4 and 10 inches (10 and 25 cm).
- The bottom of the garden should be level for maximum infiltration.
- If your garden is on a slope, utilize the soil from your digging to build a berm on the downhill side.
- Clear the area of the rain garden for any surplus soil.
To summarize, constructing a rain garden not only helps you save the environment but also offers you to grow local plants and flowers in your garden, creating a beautiful landscape for you to enjoy! So what is stopping you to benefit from all this?