Debunking myths about raingardens

A Lake Elmo raingarden masquerading as beautiful landscaping

Raingardens are increasing in popularity around the Twin Cities area and especially in the East Metro. Some local residents are planting raingardens in order to help reduce runoff water pollution to nearby lakes and rivers, while others are using them to correct drainage problems on their properties. Still others are choosing raingardens for purely aesthetic reasons. Unfortunately, although raingardens have become more prevalent in our landscape, many common myths and misconceptions continue to proliferate. Here’s the real scoop on a few of these falsehoods.

Myth #1 – Raingardens are weed patches: Here’s the deal. Raingardens need to be weeded, just like any other garden, and when they are well maintained they can be beautiful. A simple planting plan with only four to six plants may be easier to maintain than one with twenty, and people who aren’t familiar with native plants might also be more comfortable using common horticultural varieties in their raingardens. In general, raingardens should be weeded at least once in the spring and once around the Fourth of July to keep the invaders at bay.

Myth #2 – Raingardens attract mosquitoes: When properly designed and installed, raingardens absorb water within one to two days, leaving no time for mosquito eggs to hatch. In fact, the vast majority of the time, raingardens are completely dry like any other garden. Of course, mistakes do happen. If a raingarden is too deep or the soil gets compacted during planting, it might not be able to absorb water quickly enough. When this happens, the best course of action in to pull out the plants and rebuild the garden. Sometimes, though, an overactive sprinkler is the real culprit. If a raingarden is wet every morning, excessive lawn watering might be to blame.

Myth #3 – Raingardens are dangerous: Some people fear that raingardens pose a hazard to small children. Residential raingardens are only four to eight inches deep, however, not the caverns that some might imagine. When the plants are mature, it is often hard to tell that a raingarden is concave at all and, in fact, hundreds of raingardens already exist throughout the East Metro area, perhaps unbeknownst to the people they cohabitate with.

Myth #4 – Raingardens are only for people who live near lakes: In most communities, streets connect to streams through a series of underground stormwater pipes. Rain and melting snow washes off rooftops, driveways and streets and carries dirt, litter and contaminants to lakes, rivers and streams that might be miles away. Even rural properties are connected to waterways through roadside ditches. Raingardens help to keep some of that water out of the storm sewer system so that there is less pollution in community lakes and rivers. Every drop counts, whether it falls ten feet or ten miles from the edge of the water.

Myth #5 – A wet spot in the yard is the perfect place for a raingarden: Raingardens are designed to soak water into the ground. If there is a place where water is not soaking in, it might actually be a wetland. Loosening the soil and planting deep-rooted plants might help the ground to absorb water faster, but if the area is truly a wetland, the land will remain wet. A better option for drying up a wet spot in the yard might be to plant a raingarden uphill where the soil infiltrates better, thereby capturing the runoff water before it reaches the soggy spot.

Myth #6 – Raingardens are the solution to our water pollution problems: Runoff is the number one source of pollution to Minnesota’s lakes and rivers and raingardens can help to take a significant bite out of this pollution, especially in urban and suburban areas. Raingardens are just one of many tools in the toolbox, however, and they aren’t appropriate everywhere. Local communities continue to work with watershed districts, soil and water conservation districts, state agencies and private partners to tackle runoff water pollution in agricultural areas and ultra-urban areas using other types of techniques. In the East Metro, communities and residents are also helping to keep our water clean by using less lawn chemicals and winter deicers, raking and sweeping leaves, grass clippings and litter out of the streets, and shrinking streets and driveways.

For more information on raingardens, visit www.BlueThumb.org. To learn more about keeping water clean in Minnesota, visit www.cleanwatermn.org.