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

Description

Pest Overview and 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)

History: 
Mative to Europe and northern Asia. Introduced to North America as an ornamental.
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.

 

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.