As rain pours down rooftops, through gutters, across lawns and into culverts, it collects pollutants and carries these toxins and bits of trash into local rivers and streams. Along the way, rain collects in depressions in the landscape, which often results in soggy patches of lawn and shallow pools that serve as prime breeding areas for mosquitoes. This can all be fixed with a rain garden. Rain gardens are beds of plants that are located where rain naturally gathers or where rain is diverted through the use of drain pipes or swales.