A Gardeners Forum Forums General Discussion The Banter Hall Under attack..

Most research indicates that five years of intensive management is required to attempt to eradicate it. The goal of mechanical or cultural control is to deplete the energy reserves of the plant�s root system and eliminate seed production. Chemical control is the most common control strategy utilized. Research trials have demonstrated giant hogweed can be effectively controlled using herbicides; however, multiple applications are usually necessary.

Triclopyr and glyphosate (Roundup and many other products) have both been shown to be effective due to their systemic activity. The minimum glyphosate rate should be 0.75 pounds of acid equivalent per acre, but the exact rate still needs to be determined through research trials. Other products such as 2,4-D, TBA, MCPA, and dicamba may control the aboveground portion of the plant but are relatively ineffective at killing the root stock.

Applications of triclopyr and glyphosate in the fall (after the first frost) to plants established that season usually provide the most effective control in a single application. However, multiple applications per year for consecutive years may be necessary to completely control a giant hogweed population. It is important to use herbicides in accordance with the directions on the label. It is recommended that landowners who find giant hogweed on their property contact their local county Extension office or a USDA-APHIS office for current spray recommendations or to determine the status of any governmental spray program being conducted.

Regardless of the method selected, protective clothing and eyewear should be worn when working around this plant, especially when cutting, as the risk of splashing the toxic sap onto the skin will be the greatest.

Cattle, sheep, pigs and goats can graze the plant with no apparent ill effects. Grazing should begin in mid-March and continue through the growing season. Growth is suppressed but rotational grazing does not kill the plants. Pig foraging should eradicate the plant through root damage.]