Native Landscaping & Rain Gardens

A rain garden is a sunken garden that imitates nature. The mixture of plants and soil draws water into the ground before it can run off, either into a basement or the street, where it will enter the storm sewer system and eventually local waterways, such as Bassett Creek. For several years, cities around the country have been installing rain gardens to keep water close to where it falls or melts, reduce run-off into local waterways, and promote water infiltration. Since all water is ultimately connected, having a rain garden, or two or three, is really a way to act locally and have a global impact.

As forests and agricultural land are replaced by development, increased stormwater runoff from impervious surfaces increases flooding and carries pollutants from streets, parking lots, and lawns into surface water.

By reducing stormwater runoff, rain gardens can play a vital role in improving water quality by:

• enhancing the beauty of yards and neighborhoods
• helping protect communities from flooding and drainage problems
• helping protect surface water like lakes, ponds, and streams, from pollutants, carried stormwater run-off, such as fertilizers, pesticides, oil, anti-freeze, salt, and other chemicals
• increasing volume of water that filters into the ground, recharging aquifers
• providing valuable habitat for birds, butterflies, and helpful insects

If you have property, chances are you can also have a rain garden. Plan to place the garden in a sunken area or an area where water tends to run through quickly after a rain or during snowmelt. A single garden can accommodate about five percent of the drainable area (e.g., a 25-square-foot garden would accommodate 500 square feet of lawn).

Even with a low starting point, the location must be dug from six inches to four feet deep, depending on the type of soil and volume of run-off water to be dealt with. Because of this, do not place a rain garden over any utilities. Call GopherOne (651-454-0002) to have utilities marked before you begin such a project. Also, since most areas of Golden Valley have clay or silty soils that are not very porous, it may be necessary to amend the soil or install an under-drainage system before planting. If those steps are not taken, the garden will not infiltrate and will pond.

When the garden area is ready, plant hardy native wildflowers, grasses, and shrubs that can withstand both very wet conditions and intermittent drought-like conditions. Once established, your rain garden will require little maintenance, and you can sit back and enjoy the wildlife that visits.

Contrary to popular belief, properly constructed rain gardens are not breeding grounds for mosquitoes. Mosquitoes need seven to 12 days to lay and hatch eggs. Rain gardens retain water for a few hours after a storm. In fact, birdbaths, storm sewers, and lawns are more likely areas for mosquito eggs than a rain garden. And, as an added bonus, rain gardens attract dragonflies, which eat mosquitoes.

The plaza in front of Golden Valley City Hall uses rain gardens to make maintenance easier and eliminate hazards caused by uneven and deteriorated pavers, water ponding, and slippery conditions.