What is a rain garden: a rain garden is no more than a shallow depression,planted with deep-rooted native plants and positioned near a runoff source.
First, your rain garden needs to be planted in a shallow depression
By planting your garden in a shallow depression, the rainwater that flows into that garden will pond for a while and then gently infiltrate into the ground. That infiltration will help to remove excess rainwater or stormwater from your property (and storm sewer) and it will help to recharge the groundwater system.
Rain Garden Network promotes the use of shallow depressions, dug to a depth of 5″ to 7″, because it is easier for the homeowner or school kids to tackle. The idea of renting heavy equipment and hiring a professional landscaping crew to prepare you garden tends to that the fun and community out of the project.
The smaller footprint also requires less compost, additional soil (if necessary) and mulch. This makes the project less expensive and allows more people to add rain gardens to their property.
Second, your rain garden must be planted with deep-rooted plants that are native to your area
Using deep-rooted plant are the key to any rain garden. The roots of these plant can sometimes reach 15-20 feet beneath the ground. This will help to channel the ponded water deep into the ground and allow your rain garden to remain dry most of the time.
Rain Garden Network is located in Chicago and we know that the American Midwest is the home of the greatest soil on Earth. Our soils became great because of the amazing properties of the native prairie plants and grasses. After 10,000 years of these plants and grasses growing, putting down roots, distributing seed then dying back down and into the earth have made out soil highly organic and the best growing medium anywhere.
These hardy plants and grasses not only create great soils and infiltrate rain waster, they also create wonderful habitat for bees, butterflies and insects of all kinds. Prairie plants also bloom at all times of the year so they can provide a food source all season long to a vast amount number and types of insects.
Prairie plants and grasses help to reduce mosquito populations, as well. Through deep-roots and infiltration of water into the ground and the ability of plants and grasses water absorb water through their roots the rain garden should not have standing water in it for longer than a day. This deprives mosquitoes of the chance to breed and hatch.
Third, your rain garden needs to be positioned near a runoff source
By runoff source we mean a downspout(s), sump pump outlet, driveway, or even in a low spot in your lawn may attract indirect runoff through the grass. By positioning your rain garden near a one of these runoff sources you direct the water to a the rain garden, thus keeping that rainwater from going down the sewer, being a flooding hazard for your house and just creating a standing water issue that can attract and breed mosquitoes.
If you build a rain garden without its’ runoff source you will have a dry garden and you won’t have a rain garden.
Rain Garden Network
The Rain Garden Network was started in 2003 with the intention of bringing simple, proven and inexpensive solutions for local stormwater issues to individuals, homeowners, groups, organizations and municipalities.