These depressions are generally 3-6 inches in depth and they are usually located at an area where a natural slope ends. Many people wonder why building a rain garden is necessary? When there is rain or a storm, the water collected from impervious surfaces from a home like the roof or downspout carry pollutants, insecticides and other harmful substances.
The storm runoff carrying these pollutants flow into the street and into streams, rivers and lakes. This increases level of pollutants in water bodies, disturbing the ecological balance.
A rain garden helps in accumulating the stormwater runoff from your property in one area and the water is slowly percolated into the ground. Here we are going to discuss the method for building a rain garden in your property.
How to Make a Rain Garden
Select a Location for the Rain Garden
If you are wondering how to build a rain garden, the first thing you need to do is select a location for the rain garden. Select a location for the rain garden that receives plenty of sunlight so that the excess water gets evaporated quickly. Make sure that the location of the rain garden is at least 12-15 feet away from the perimeter of the house.
This is because if it is too near the house, it will cause water to seep into the foundation which might compromise the integrity of your house's foundation. An ideal location for a rain garden is a spot that ends at a natural slope. This will make the water from the stormwater runoff naturally flow to the area.
Plan the Shape and Size for the Rain Garden
You can have a rain garden of any size, but make sure that the size is proportional to the area of the property and that it enhances the landscape. The depth of the rain garden for a ground which is fairly level should be around 3-5 inches. For ground that has a slight slope to it, a depth of 6-8 inches is sufficient.
A natural shape like an oval, kidney or a teardrop shape looks more attractive than a square or rectangular shaped rain garden. So choose a shape that looks natural and gels well with the landscape.
Dig the Ground for the Rain Garden
Once the location of the rain garden has been established, it is time to dig the ground. Define the perimeter of the rain garden by laying a piece of string. Install wooden stakes around the perimeter of the rain garden that you are about to dig. Now start digging the ground to the required depth using a shovel.
If you plan to build a rain garden of a larger depth, it is advised to use professional services for digging the ground. If you are building the rain garden on a slope, you will need to make a berm on the downhill side of the rain garden. To build a berm just compact the soil that you dug out on the inside of the downhill edge of the depression.
The idea is to have the same elevation for both the uphill and downhill side of the rain garden so that water does not flow out of the depression, but percolates slowly into the ground.
Plant Grass and Shrubs on the Depression
After you have dug the depression on the ground and created a berm around it, it is time to plant your garden. Select a variety of tall grasses, ferns, flowering plants and shrubs and plant them in the garden. Choose rain garden plants and shrubs that can thrive in a moist environment.
Plants that have a well established root system are ideal for a rain garden as they help in absorbing the excess water without any fear of rotting. Add a layer of mulch to the garden bed taking care that you do not bury the crowns of the plants with mulch. Water the plants regularly after mulching them.
Once the rain garden is established and the plants grow and thrive, remove weeds from the garden periodically. You can beautify the garden by using small pebbles or river stones along the edge of the berm.
Creating a rain garden is not a difficult task, although it can be a little time-consuming. However, the benefits of having a rain garden are many and you should definitely build one in your front or backyard.