CONCERN Giant hogweed can have negative impacts on both the environment and human health. It is able to outcompete native plants by monopolizing the light supply with its broad leaves and tall stem. The sap of giant hogweed can cause severe photodermititis in humans. Contact with the sap on skin, coupled with exposure to UV rays, can cause burning and blistering. The affected area may take months to fully heal, and can remain sensitive for years. HISTORY G
Giant hogweed originally came from Asia. It was introduced to North America as an ornamental garden plant. It is now found in many provinces throughout Canada, as well as a number of US states. There are only a couple of known sites on PEI, and all are contained within private gardens. IDENTIFICATION Giant hogweed has several look-a-likes that grow in PEI, including: cow parsnip, woodland angelica, and Queen Anne’s lace. Here are a few features you can use to positively identify giant hogweed: Grows much taller than the look-a-likes at 5 m tall Umbrella-shaped flowering portion can be 1.5m in diameter Hollow stem covered with purple streaks and spots
The most effective method of control for giant hogweed is physically removing plants and seeds. Removing seeds will ensure the existing plants cannot reproduce, because giant hogweed produces seeds only once in it’s lifetime. Removal is best undertaken early in the growing season when plants are small and manageable. CAUTION: Proper protection must be worn to avoid contact with sap when handling giant hogweed. Plants removed from a site should be placed in clear plastic bags and allowed to dry in the sun for a week. Plants can then be transported to a local landfill. It is important that native plants be planted where invasive species were removed from to prevent future invasions.
Try these plants in your garden as alternatives to giant hogweed: Red elderberry (Sambucus racemosa) is native to PEI. It grows to be 2-6ft, which is much shorter than giant hogweed. However, like giant hogweed, it produces clusters of small white flowers at the ends of branches. These flowers yield red berries which attract many forms of wildlife.