Today I want to talk about Rain Garden Design Plans. Have you ever wondered what a Rain Garden is? Well read below to find out what is a rain garden, the benefits of having a rain garden, Rain garden design plans, how to create your very own rain garden, and discuss the different zones and the plants for each zone, that can or can’t handle large amounts of rain.
What is a Rain Garden
A rain garden is a planted low depression area that slowly soaks up excess water. The water is collected by run off from roofs, driveways or even a street. Having a rain garden can be a cost effective way to take care of excess water on your property by selecting specific plants that thrive in more wet conditions. You can add flowering perennials and decorative grasses to accent the rain garden. Most rain gardens are 100 to 300 square feet and shaped like a kidney.
Rain Garden Benefits
- Rain gardens can help filter out pollutants in runoff
- Provide food and shelter for butterflies, song birds and other wildlife
- Mosquitos aren’t usually an issue because most soils absorb water in 7 to 10 days, before the larvae hatch.
- The plants also use storm water instead of water from your hose, helping reduce water bills.
- Removes standing water in your yard
- Recharges the ground water supply
- Increase in beneficial insects that eliminate pests
- Reduce potential of home flooding
Rain Garden Design Plans
Look around your property to find the best place for a rain garden. Just make sure to not put it over any septic area, well water area or by any hidden power or gas lines. Always check with your local electric and gas company to inspect the area for underground surprises. Consider where you might be able to view the rain garden to get the most enjoyment out of it.
Once you find your location, test the soil to see how long it will take for the water to drain. Not all soil is good for a rain garden. Do the test the day after a rain when the soil is saturated. Use a shovel to dig a hole. Use a measuring tape to make it six inches deep and six inches wide, and fill it with water.
Let it drain and re-fill it. Wait 24 hours to see if the water is gone. If it is, the site is, probably suitable for a rain garden. If it’s not, test another part of your yard or consider making a pond instead.
Put the rain garden in a natural low spot that fills with water after a storm, if possible, and in an area that gets a half to a full day of sun. Position it so the long side faces uphill. If you don’t have a natural slope or low spot, aim your downspouts toward the depression instead.
Use downspout extensions or dig a shallow trench filled with rocks or gravel to direct the water to the garden. Make sure to get any required permissions from your local zoning board, and that your neighborhood doesn’t have any restrictions, before you start.
How to create your Rain Garden
Once you have decided on the rain garden spot, start preparing the rain garden site. When creating a rain garden they are usually 6 to 8 inches deep, with the deepest part in the center. Keep the depression level when working the area by sloping towards the center keeping the area a saucer shape.
Avoid putting the garden under a tree or digging where you might damage tree and shrub roots. Before you dig, remove grass and weeds from the rain garden site. Use a hoe or cover the vegetation with landscaping fabric or a black tarp for a few days and let heat from the sun kill it.
If you want to add compost to your rain garden to help your plants grow, dig deeper to allow for the amount you add. If you want a finished rain garden that is six inches deep, and you add two inches of compost, dig the depression eight inches deep.
Use the soil you remove to create a berm, or low wall, on the downhill side of the depression. If desired, make berms on the other sides, too. They’ll help keep the water from spilling out until it can be absorbed.
Make the berms six to eight inches above the ground level, add more topsoil if needed. Pack down the soil in the berms unless you plan to grow plants on them. If you plant in the berms, first put your plants into place and then gently firm the surrounding soil.
The goal is to keep the soil from washing away and not compact it too much for the roots to grow. You can use landscape fabric on the berms to help hold the soil in place. Use a sharp knife to cut holes for your plants.
Don’t mulch with wood chips or pine bark, they are too light and can float away. To make it uniform, use the same decorative tones and rocks to line the sides of any trench you dug to direct the water into
the rain garden.
Rain Garden Plant Ideas
For best results get plants that are native to the area and use wildflowers and other low-maintenance plants. Use plants with well-developed roots, not seeds. Seeds can be washed away by the storm water before they have time to sprout.
The plants should be able to handle dry spells, when there is no
water in the depression, and times the depression is holding water. Put
plants that like wet conditions where the collected water will be the
If the rain is sparse, give the plants about an inch of water a week for the first year, or until they’re established. Space the plants by following the directions on their tags or labels and use three
to seven of each variety for a good display of colors and textures.
Native ornamental grasses and sedge are also useful and will develop
strong root systems to help hold the soil in place. As the plants grow and fill in, they’ll crowd out the weeds and the rain garden will be easier to maintain.
The Wet Zone
This is the deepest part of the rain garden and holds the most water. The plants listed below can handle lots of water, up to 6 inches of standing water. However, the rain garden should be created to drain the water within 24 hours.
Perennials and Ferns
- Blue Flag Iris
- Cardinal Flower
- Cinnamon Fern
- Golden Ragwort
- Golden Rod
- Green Bullrush
- Marsh Marigold
- Monkey Flower
- New England Aster
- Royal Fern
- Swamp Milkweed
- Swamp Rose Mallow
- Swamp Sunflower
- Black Choakberry
- St. Johnswort
- Silky Dogwood
- Swamp Rose
- Bald Cypress
- Black Gum
- Black Willow
- Pond Pine
- Swamp Oak
The Middle Zone
- Blue false indigo
- Blue Star
- Bottlebrush grass
- Culvers root
- Obedient plant
- Threadleaf coreopsis
- American Beautyberry
- Broad-leaf Meadowsweet
- Narrow-leaf meadowsweet
- Red-Osier Dogwood
- Sweet Pepperbush
- Virginia Sweetspire
- Paw Paw
- Red Maple
The Transition Zone
This area is the area between the rain garden and the non-rain garden area. This area will dry the fastest and will receive water less frequent during a downpour rain. Plants in this area can be any typical garden plant but recommended to use native plants to promote a wildlife sanctuary.
I hope you found this informative and helpful. As always make sure you use plants native to your area and your hardiness zone.
Do you have a rain garden?
Please share with me your rain garden ideas and plants used.
I would love to hear from you.
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