Goutweed, also known as ground elder or bishop's weed, is a highly invasive perennial plant in the carrot family. Native to Europe and Asia, it was introduced to North America as an ornamental and has since become problematic due to its aggressive spreading through rhizomes (underground stems), its ability to thrive in various conditions, including shade, and how well it outcompetes native vegetation. It's often found in woodlands, along waterways, roadways and in disturbed areas.

Learn to Recognize Goutweed

The images and descriptions below will help you to recognize goutweed. You can use a plant identification app on your mobile phone. Check out our post on mobile apps for links to some of our favourites.

Leaves

Two varieties of goutweed exist, variegated and non-variegated. The leaves of the non-variegated variety are solid green throughout, while the leaves of the variegated variety are outlined in white/cream-coloured margins with a blue-green base. The lower leaves are typically doubly compound while the upper leaves are ternate (divided into 3 groups of 3 leaflets).

Flowers

The plant produces white flowers that are organized in flat-topped umbels (umbrella-shaped clusters) on deep green, vertical standing stalks that can grow up to 1 m tall. These flowers typically bloom from June to August, occasionally as early as May in specific regions. Plants in shaded areas with limited sunlight may produce fewer flowers. Each flower develops a small, brown, oblong, flattened seed known as a schizocarp, measuring 3-4 mm in length.

How Does it Spread?

Goutweed is considered one of the worst garden plants due to its invasive nature. It spreads aggressively via rhizomes, forming dense mats that can outcompete native plants. The flowers produce seeds, however, it primarily spreads by the aggressive underground network of rhizomes which allows it to extend up to 70 cm per year from its parent plant. The rhizomes easily break, giving rise to new plants from the fragmented pieces.

Control

Managing goutweed can be challenging, but several methods can be used: Note that Goutweed can be persistent, so multiple control methods and repeated efforts may be required. Regardless of the control method used, the patch should be carefully monitored periodically for a few years. New shoots should be dug up and destroyed. Once goutweed control has been achieved, revegetation with native or non-invasive exotic plant materials is recommended.

Manual Removal

Small patches of goutweed can be eliminated by careful and persistent hand-pulling or digging up of entire plants along with underground stems (rhizomes).. Be careful to pick up all rhizomes which, if left behind, can reroot and sprout new plants.

Mowing

Repeated mowing can weaken the plant, but may not eradicate it completely.

Tarping

Covering the area with a tarp (especially a black, opaque tarp) can block sunlight and kill the plant over time. Tarps may need to be left in place for at least 2 seasons. Once the tarp is removed the area should be surveyed regularly for return growth.

Herbicide

In some cases, systemic herbicides may be used, but caution is advised to avoid harming surrounding vegetation.

Disposal

Goutweed can spread from root fragments. When removing plants , put all parts of the plant (roots, flowers, seeds, leaves and stems) in a black garbage bag and put in the garbage bin.

Do not put any plants or fragments into the town compost or on a compost pile on your property.

Bibliography

Ontario Invasive Plant council – Goutweed https://www.ontarioinvasiveplants.ca/invasive-plants/species/goutweed/

Invasive Species Centre – Goutweed https://www.invasivespeciescentre.ca/invasive-species/meet-the-species/invasive-plants/goutweed/

Government of Quebec - Sentinelle (Invasive Alien Species – Flora – Terrestrial Plants – Goutweed0. Retrieved on July 9, 2025 .https://www.pub.enviroweb.gouv.qc.ca/scc/Catalogue/ConsulterCatalogue.aspx

iNaturalist - https://inaturalist.ca/taxa/51741-Aegopodium-podagraria

Goutweed: An Invasive Plant to Avoid