Goutweed or Bishop’s weed (Aegopodium podagraria )

Invader Type: 

Control

Mechanical Control: 

New infestations should be treated rapidly before an extensive root system is established. Hand pull and grub-up all stems, roots, and rhizomes.  Bag all plant material and allow to sit for one week before disposing in a landfill. Re-check site each year.

For large infestations, cover the patch with thick black plastic in the spring as soon as new growth appears. Lay plastic on an area larger than the patch and secure edges with sandbags, bricks or ground staples. Leave for a full year.

Goutweed may also be cut in late summer, after leaf-out, and then covered with plastic.

DO NOT COMPOST! DO NOT DISCARD IN WOODS OR FIELD!

Plant fragments will re-sprout.

 

Chemical Control: 

Active ingredients commonly used in herbicides: Glyphosate or aminopyralid

If foliar spraying only:

  • Foliar spray when plant is fully leafed out (May-October)
  • Spray leaf surfaces with low volume backpack sprayer, or high volume mist blower

Low Volume Backpack Sprayer

  • Herbicides (active ingredient): glyphosate or triclopyr with surfactant
  • Used to target plants and minimize drift to desirable species

Photos

Photos: 

Description

Identification: 

Bishop’s goutweed is a creeping perennial that can grow to 3 ft. (1 m) tall. Compound, alternate leaves with sheathing bases. The leaves at the top of the stem are smaller and have fewer leaflets. The leaflets are dentate and 1-3 in. (2.5-7.6 cm) long. Blooming occurs in June, when a flat, 2 -4 in. (5-10 cm) wide cluster of small, white flowers develops. Bishop’s goutweed flourishes in moist, shaded areas such as forest edges and disturbed forests. (www.invasive.org)

Reproductive Strategy / Lifecycle: 

Goutweed is an aggressive perennial that reproduces primarily vegitatively through a rhizome system. Seeds require cold stratification to germinate, and the seed bank is short-lived. Seeds usually will germinate the next year after initial dispersal. New foliage appears in early spring and flowers bloom in June with small white umbels. The seeds turn brown when they ripen in late summer.

 

Dispersal: 

Existing populations increase rapidly through the rhizome system. The plant will also spread through waterways. Humans are a major factor in long-range dispersal of goutweed; it is a popular garden plant and continues to be sold as an ornamental groundcover. Even a tiny root fragment can create a new plant.

 

BE AWARE OF LOCAL PLANT SALES AND GENEROUS GARDENING FRIENDS!

Practice safe gardening - be sure the plant you accept was growing in invasive-free soil.

Habitat: 
Goutweed grows in abandoned fields, pastures, gardens, and open forests. It prefers full sun, but is highly shade tolerant, able to dominate forest understories, and does very well in light to moderate shade. Seedlings do best in disturbed soil in sunny locations, and flowers are fewer in dense shade. The leaves will die in conditions of intense heat or drought. This plant will tolerate a wide range of soil quality and pH. Clsa
History: 
Mative to Europe and northern Asia. Introduced to North America as an ornamental.
References: 

Photos: (c) L. Mehrhoff University of Connecticut; (c) J. Randall; (c) R. Videki Doronicum Kft

Threat

Ecological Threat: 
  • Goutweed, also called Bishop’s Weed, (Aegopodium podagraria) spreads quickly by fast growing underground roots called rhizomes.  Even a small piece of rhizome can re-sprout into a new plant, so take care to dispose of all plant material carefully and clean your clothing and shoes after going through or working with a patch of goutweed.
  • Beautiful floodplain forests can easily become inundated with goutweed, impacting the populations of ostrich ferns, silver maple and other native plants.
  • While the plant is illegal to sell, local plant sales still sell this plant and some gardeners think it makes a nice groundcover, inadvertently introducing a problem into their flower beds and nearby natural areas.