Constructing the Rain Garden
Constructing the Rain Garden
Once permission is received, plants are selected, a site is chosen, and materials are collected, the building and planting of the rain garden may begin. Students should follow the instructions below:
- Decorate the boards.
Before building begins, you may want to decorate the sides of the 2-inch x 12-inch boards. You can paint pictures of the plants you will grow, pictures of the animals that might use the rain garden for habitat, or maybe even a picture story showing how a rain garden helps to keep streams and rivers clean. If you decide to paint on your 2 x 12 boards, make sure the boards dry completely before proceeding any further.
- Dig the rain garden.
To determine how large an area to dig, outline the area that you want your rain garden to cover with the 2 x 12 boards to get an idea of the garden's size. Use shovels to dig up the top layer of dirt and grass inside the outline made with the 2 x 12 boards. Turn the soil over so that the grass is completely covered up—this is a very important step. If you do not turn the grass over, it may grow up through the rain garden and compete with your native plants for water and nutrients. Use shovels to break the big clumps of dirt apart. This will make it easier for the native plants to take root. If runoff is heavily focused into the rain garden, you may want to place some gravel at the source of the runoff so young plants do not wash away.
- Build the frame.
The frame, built with the 2 x 12 boards, will provide a wall to keep your soil and plants in the rain garden. The bottoms of the boards should be buried about 1 or 2 inches in the ground to keep the soil inside the rain garden from coming out underneath. The frame needs to be fairly level, so you will have to adjust how deep the boards are buried in the ground depending on the slope of the earth where you build the rain garden. Use the stainless steel elbow brackets and screws to fasten the corners of the boards together. Then use the 2-foot long sections of steel reinforcing bar (rebar) to stabilize the boards. Have an adult help you hammer the rebar pieces into the ground up against the boards of the frame. Alternate the pieces of rebar on the inside and then the outside of the frame every 2 to 3 feet. Hammer them down so they are below the top of the frame. Then fill in the frame with topsoil up to a few inches from the top of the boards.
- Plant the rain garden.
Now you are ready to put your plants or your seed in the rain garden. If you are using potted plants, you will need to dig holes in the soil of the rain garden deep and wide enough to hold the roots of the plant. Spread your plants around so that they cover the whole rain garden. Be very careful not to compact the soil in your rain garden while you are spreading your plants. If the soil gets too packed down, the plants will have trouble rooting. If you are using seed, mix the seed with an equal amount of sand first and then distribute it evenly around the whole rain garden. Whether you use potted plants or seed in your rain garden, be sure to put down a layer of mulch, like pine bark strips or straw. The mulch will keep in moisture and protect your plants/seeds from weeds. Finally, water the rain garden thoroughly.
- Maintain and care for the rain garden.
Now that you have successfully planted your rain garden, all you have to do is take care of it so that it will do what it is supposed to do. Because the native plants you chose can tolerate periods of dry weather, you will not need to water your rain garden unless it does not rain for a long time (2–3 weeks). Weeds will probably grow in your rain garden and you will need to pull them out so that they do not compete with your plants. This can be done about once a month.
- Congratulate yourself.
You've just built your very own rain garden and you know how it will help protect our streams and rivers from storm water runoff and restore wildlife habitat. So if someone asks you, "What is a rain garden?" you can tell them and show them.