Species Management and Control Information

Giant hogweed
Heracleum mantegazzianum Sommier & Levier

Source: The following information is taken from a number of sources and those sources are identified at the beginning of the referenced information. The intent of this resource is to provide the user with as much of the information that exists for management and control of this species as is practical. It is important to note that new and improved methods are added regularly which will require you to visit the websites provided for updates on this information. Bibliographies and resources referenced by these sources are not included here, but are included at the websites from which this information was extracted.

READ THIS FIRST! Before administering any of the following management and control options, it is imperative that you are familiar with the background information provided under the General Management and Control Section. For additional, and potentially more current, information on management and control of this species, use the Mid-Atlantic Exotic Pest Plant Council (MA-EPPC) listserve or any of the other listserves identified in the Resource - Listserve section of this tutorial. You will find directions for subscribing to the list serve there. The MA-EPPC listserve has an archives feature that saves past discussions (beginning in 1999) about specific species control. These messages are at: http://groups.yahoo.com/group/ma-eppc/messages.

GENERAL MANAGEMENT CONSIDERATIONS:

In Pennsylvania, Giant hogweed is a Pennsylvania Noxious Weed. If you find hogweed anywhere in the commonwealth, call the Toll Free Giant Hogweed Hotline at 1 (877) 464-9333. The PA Department of Agriculture can assist you in hogweed control and eradication.

MANUAL AND MECHANICAL CONTROL:

USDA Animal Plant Health Inspection Service - Pest Plant Quarantine - Domestic Programs Pest Evaluation - AERO - Raleigh, NC - http://www.invasive.org/eastern/other/hogweed.html - November 16, 2001.

Mowing does not appear to be effective. The Pennsylvania Department of Agriculture has used a rototiller and planted a lawn seed mix to return areas to a natural state.

BIOCONTROL:

USDA Animal Plant Health Inspection Service - Pest Plant Quarantine - Domestic Programs Pest Evaluation - AERO - Raleigh, NC - http://www.invasive.org/eastern/other/hogweed.html - November 16, 2001.

In Switzerland 12 phytophagous insect species found on native hogweed have been identified as possible candidates as biological control. Cattle and pigs are cited as possible biocontrol agents.

CHEMICAL CONTROL*:

USDA Animal Plant Health Inspection Service - Pest Plant Quarantine - Domestic Programs Pest Evaluation - AERO - Raleigh, NC - http://www.invasive.org/eastern/other/hogweed.html - November 16, 2001.

The Pennsylvania Department of Agriculture recommends utilizing both pre and post emergent herbicides, plus competitive vegetation. PDA applies Pre-M at 1-1.5 oz./1000 s.f. in late-March. When germination of hogweed seed was noticed, Transline was incorporated at .5 oz./1000 s.f. along with Pre-M at the 1.5 oz/1000 s.f. rate. This continued until other vegetation started to grow. Later in the season, they used Drive at 1 oz./A. Post-emergent applications of 91% Thinvert, 7% Garlon 3A and 2% Transline are initiated in mid-April. These herbicide applications continue until snowfall covers the hogweed.

Previously, glyphosate has been considered the most effective herbicide, but it should be used with caution around desirable plants. The herbicides 2,4-D, TBA, MCPA, and dicamba are not effective on GHW roots. Rodeo (glyphosate) has been recommended in wet areas. Herbicides should be applied to large plants with protective clothing.

* Mention of pesticide products in this document does not constitute endorsement of any particular material.