Virginia Water Resources Research Center

The Water Cooler

Exploring Connections Between Plants and Water

Fairfax County Celebrates Virginia’s First Invasive Plant Removal Day

Article and Photos by Gregory R. Sykes, Volunteer Leader for Fairfax County’s Invasive Management Area Program. The Virginia Water Resources Research Center thanks the Fairfax County Invasive Plant Management Program for providing this article.  Opinions expressed in the article are not necessarily those of the Water Center.

Invasive, non-native plants threaten worldwide habitats, from tropical ecosystems to polar regions. These aggressive species displace native plants, thereby altering the local habitat by depriving wildlife normal food and shelter. Furthermore, the invasive plant roots often are less capable of retaining soil than native species, especially along stream banks, thereby increasing erosion potential. Removing invasive plants and sowing native flora is a fantastic way to improve water quality and wildlife habitat in any biome. For the past three years, Fairfax County Park Authority (FCPA) has joined this global cause through the Invasive Management Area (IMA) program ( Nearly 40 sites, mostly in stream valleys throughout the county, combine volunteer dedication and technical experience to reduce the coverage of some of our area’s worst invaders.

The Fairfax County Board of Supervisors proclaimed April 12, 2008, as Invasive Plant Removal Day—the first such day in Virginia! Participating in this event, 13 IMA sites had weed eradication workdays while previous removal efforts enabled volunteers to reestablish native species in cleared zones. To understand the process, here are detailed events at one locality—Royal Lake Park/Pohick Valley Stream Valley Park—which lies within a riparian zone. In riparian areas, erosion control receives top priority. This site works best when we can combine a “pull-and-plant” session. The invasive plants choking this plot included Lonicera maackii (Amur honeysuckle), Rosa multiflora (multiflora rose), Hedera helix (English ivy), Alliaria petiolata (garlic mustard), and Elaeagnus umbellata (autumn olive). Invasive plants, combined with the nearby active storm sewer discharge, threaten to degrade this park; besides increased erosion under the shallow roots of the ivy, the storm water spreads seeds further into the park downstream.

Volunteers immediately planted native plants in the holes left after removing invasive shrubs. These new plants can curb any erosion that might result from the now absent invasive plants. Replacing the lost vegetation, volunteers planted a Platanus occidentalis (American sycamore) which has extensive surface roots ideal for soil retention, and a Diospyros virginiana (American persimmon)—a species with an intricate, suckering root system. Part of this site retains water for several days after a rain. This muddy plot provided perfect conditions for moisture-thriving plants, such as Cephalanthus occidentalis (buttonbush), Cornus amomum (silky dogwood), and Ilex verticillata (winterberry). Along a drier hillside, volunteers planted Lindera benzoin (spicebush), Vaccinium corymbosum (highbush blueberry), and Viburnum acerifolium (maple-leaf viburnum). Finally, herbaceous plants, such as Helianthus divaricatus (woodland sunflower), Senecio aureus (golden ragwort), Onoclea sensibilis (sensitive fern), Polystichum acrostichoides (Christmas fern), and Rudbeckia pinnata (grey-headed coneflower), filled gaps with native groundcover.

Once these plants mature, this little parcel will be a haven for wildlife, especially birds and butterflies. As for humans, this strip will transform from a previous tangle of festering weeds into a model woodland area. It is an excellent example of how people can both use plants to better serve a critical function (erosion control) while promoting wildlife. Recognition and awareness days, like the one sponsored by our local government, can enhance people’s understanding of the critical link between healthy ecosystems and healthy water.

On May 2, 2009, Fairfax County will participate in the first state-wide Invasive Plant Removal Day being hosted by the Virginia Master Naturalists and the Virginia Native Plant Society. Participants at Royal Lake Park will target garlic mustard, multiflora rose, and several other species. The exact details for Invasive Plant Removal Day are under development but will be posted soon at the Virginia Master Naturalists website:

For more information on the Fairfax County program, contact IMA Volunteer Coordinator Kathy Frederick at:
or visit the IMA website:

For further reading, please look into these websites:

…and these books:

Audubon Society of Northern Virginia. 2005. The Nature of Change—Preserving the Natural Heritage of a Dynamic Region: Audubon at Home in Northern Virginia. National Audubon Society, Inc. pp.79.

Burrell, C. Colston. 2006. Native Alternatives to Invasive Plants. Brooklyn Botanic Garden, Inc. pp. 239.

Randall, John M. and Janet Marinelli. 1996. Invasive Plants—Weeds of the Global Garden. Brooklyn Botanic Garden, Inc. pp. 111.

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