Nature Article
American Pokeweed
09/07/2007
Invasive Weed: American Pokeweed (Phytolacca americana)
Threat: Poisonous and invasive. American pokeweed has disrupted the migration patterns of certain bird species by producing large amounts of fruit at a time of year when few native plants do (www.nescb.org/epublications/fall2001/invasives.html). The plant is considered aggressive and invasive, but is fairly new to the Pacific Northwest. With vigilance, we can stop or slow this weed before it becomes established and causes damage.
Description: American pokeweed is a large, smooth-leaved, branching herb from a large, perennial rootstock, with green, red, or purple stems. The leaves are alternate and simple. The flowers are white, on a long stem, more or less erect. Fruit is a dark purple berry composed of 5-12 segments fused in a ring. The stem is drooping. Phytolacca rigida differs by having shorter, erect fruiting stems.
History: American pokeweed is native to the southeastern United States and has the potential to become very difficult to eradicate in the Pacific Northwest's moist, moderate climate. The plant was likely brought to this region for landscaping interest. Many parts of the plant are highly toxic and may cause death if eaten (www.ces.ncsu.edu/depts/hort/consumer/poison/Phytoam.htm).
Spread: Berries are spread by birds and also by humans. The plant is commonly found in disturbed areas.
Control: Pokeweed is a perennial plant, which means the stems, leaves, and flowers die each year, but the roots (and therefore the plant) stay alive through the winter. In spring, each plant will send up new stems and leaves. The large tuberous root system must be dug out and disposed of in order to eradicate the plant. Pokeweed has sometimes been mistaken for Japanese knotweed, another invasive species in northwestern Oregon, due to pokeweed's hollow red stems and large ovate to lanceolate leaves.
Alternatives: Red elderberry (Sambucus racemosa) and blue elderberry (Sambucus nigra) are native deciduous shrubs that provide berries for birds and wildlife. Check with a reputable nursery for other attractive shrubs that are not invasive.
For more information:
University of Florida, Agronomy Notes - agronomy.ifas.ufl.edu/docs/July2005.pdf
Controlling Common Pokeweed - web1.msue.msu.edu/iac/434/Common pokeweed GR.pdf
Prepared by Kathy Shearin, EMSWCD Program Coordinator, Sustainable Urban Landscapes, East Multnomah Soil and Water Conservation District, as a project for the Clackamas, Clark, Multnomah, and Washington Counties Cooperative Weed Management Area.
