California Invasive Plant Council

Heracleum mantegazzianum

Common names: giant hogweed

Heracleum mantegazzianum (giant hogweed) is a herb/ (family Apiaceae) with white flowers and large toothed leaves found in the northwestern ranges of Oregon. It is native to central Asia. It favors grasslands and riparian and bottomland habitat. It reproduces only by seed. Seeds fall within 13 feet of the parent plant and can be carried by water and wind. Sticky seeds attach on to humans, animals and machinery.

Cal-IPC Rating: Watch

CDFA Rating: A?

Explanation of CDFA ratings

• A – A pest of known economic or environmental detriment and is either not known to be established in California or it is present in a limited distribution that allows for the possibility of eradication or successful containment.
• B – A pest of known economic or environmental detriment and, if present in California, it is of limited distribution.
• C – A pest of known economic or environmental detriment and, if present in California, it is usually widespread.
• D – An organism known to be of little or no economic or environmental detriment, to have an extremely low likelihood of weediness, or is known to be a parasite or predator.
• * – An asterisk next to the rating indicates that a plant is included in the CCR Section 4500 list of California State Noxious Weeds.

More details

Assessment(s)

Plant Risk Assessment - An evaluation of the potential for a plant to be invasive in California.

Weed Management Notes

• Management Notes - Information on management techniques and effectiveness from the University of California Cooperative Extension’s Weed Research & Information Center.

Cal-IPC Newsletter Articles

There are no newsletter articles associated with this species yet.

Cal-IPC Symposium Presentations

Presentations are linked where available. Where a presentation is not available, find more information by reading the abstract in the Cal-IPC Symposia Archive.

• Weed alerts and other invasive plant highlights for 2020. Burger, Jutta; Price, Robert (2020)
• 2019 Weed Alerts. Burger, Jutta; Price, Bob (2019)

Other Heracleum mantegazzianum Information

• CalPhotos - Images of plants taken mostly in California.
• CalWeedMapper - Distribution map of this species in California with ability to determine regional priorities.
• EDDMapS - Distribution of this species in North America.
• USDA PLANTS Database - Information on identification and distribution, with links to websites in individual states.