When bioretention facilities are utilized for water quality improvement in residential areas, the aesthetics and visual characteristics of the design must be a prime consideration. A facility located at the entrance to a commercial building, a residential neighborhood or located in the front yard of a residential lot may provide a landscaped focal point for the community. It is appropriate in these settings to choose plants that have ornamental characteristics that visually link the facility into the surrounding landscape. In all cases, the landscaping requirements for bioretention are intended to be flexible enough to provide the designer with opportunities to meet local landscape requirements.

Consider the bioretention facility a mass bed planting. The entire facility should be planted at a density that the foliage will completely cover the facility after the second growing season. Choose a variety of plant species that will add interest to the bioretention facility with each changing season. Perennials provide vibrant colors from early spring through fall while ornamental grasses and evergreen or berry producing shrubs can add winter interest. Species that require regular maintenance (shed excessive amounts of fruit or are prone to storm damage) should be restricted to areas of limited visibility and away from pedestrian and vehicular traffic. Where the facility is located below overhead utilities, select tree species that comply with local utility height and clearance requirements.

In residential applications, consider using the dominant species of plant material used around the entrance to the home to visually link the bioretention facility with the home.

Where the ornamental garden receives runoff from the street, choose salt tolerant species. In many regions, most salt applications will wash through the soil and not adversely affect the plants. However, it is still recommended that snow and ice be treated with sanding applications rather than salting. If salt is used, apply sparingly within bioretention drainage areas. Never use fertilizer to melt ice. For more information see Maryland Cooperative Extension Fact Sheet 707, Melting Ice Safely.

Mulch the entire bed with 2 to 3 inches of hardwood mulch. Fresh bark mulch should be used when possible to maximize nitrogen retention. If possible, use shredded instead of the "chip" variety to minimize floating action. All mulch should be free of foreign material including plant material.

CONTINUE TO Open Space Meadows

The above information was derived from the Prince George's County Bioretention Manual.

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The information on this website was compiled by T.E. Scott & Associates, Inc. from various sources.

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Last modified: 10/23/09