Easy Gardener • Pat Howell
	What is a raingarden? December, 2005

Last month in this column, we wrote about the plans for a rain garden in Takoma Park to be built in Forest Park (at Elm and Prince George Avenues).

What is a raingarden?

First, what it is not: It is not a mosquito breeding area. the water raingardens catch seeps into the soil within a few hours or overflows into the storm drain in the event of a very large storm.

It is not a pond; rather, it is more like a big sponge. The sponge gets very full when it rains, but there will be no standing water in the raingarden for more than a few hours.

So, what is it?

Raingardens are one of many stormwater management techniques. When it rains, water flows over impervious surfaces such as asphalt, concrete, roofs, lawns. It runs off quickly and heads for the nearest storm drain. The water carries sediment and other pollutants, including chemical lawn weed-killers with it as it rushes down the storm drain and into the nearest creek. The runoff causes bank erosion, water quality degradation and other serious problems.

Raingardens help hold some of the water where it falls long enough so that it can seep into the ground. Raingardens are built by digging out some soil (in the case of Forest Park about 6 inches deep); using the dug-up soil to build a berm around the area that acts like a tiny dam; putting back in soil amended with very absorbent materials; and planting native plants in the finished area.

The Forest Park raingarden

Photo: Ed Murtagh Jenny Reed is adding plants to the new raingarden while community children look on in Forest Park.

The Forest Park raingarden will help keep the rain that falls in the park in the park, reduce erosion that affects the trees, keep runoff and sediment out of local streams, and demonstrate good stormwater management techniques. This raingarden was built through a partnership effort by Friends of Sligo Creek; Natural Resources Design, Inc.; The City of Takoma Park; and neighborhood citizens--all of whom donated time and materials to make the project a success. And it was done in a remarkable turn-around time of less than three weeks! A huge thank-you to one and all.

The plant materials are almost all natives that grow well in shady spots that are periodically very wet, and periodically very dry. The plants include: Inkberry Holly (Ilex glabra) - Evergreen shrub; Sparkleberry Holly (Ilex verticillata) - Deciduous shrub; Virginia Sweetspire (Itea 'Lil Henry') - Deciduous shrub Chokeberry (Aronia) - Deciduous shrub; River Birch (Betula nigra) - Tree; Christmas Ferns (Polystichum acrostichoides) - Perennial; Autumn Ferns (Dryopteris erythrosora) Whitewood Aster (Aster divaricata) - Perennial; Woodland Phlox (Phlox divaricata) - Perennial Solidago 'Fireworks' - Perennial; Columbine (Aquilegia) - Perennial; Japanese sedge grass (Carex 'Little Midge') - Evergreen; Rudbeckia hirta - Perennial; Arrowwood Viburnum (Viburnum dentatum) - Deciduous shrub.

For more pictures, see Friends of Sligo Creek website: www.fosc.org/AL-TPRainGardens.htm. Or go visit!

Pat Howell is a Takoma Park gardener and landscape designer/contractor. She is available for hand-holding and answering questions through Deephaven Landscapers.

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