Hogweed, or giant hogweed, classified as Heracleum mategazzianum, is a plant that can pose a serious health risk to individuals who come in contact with it. The plant is typically found in wastelands and alongside railroads and rivers. However, the plant can also show up near gardens and lawns, where it must be eradicated immediately.
The sap in hogweed can cause severe blistering and is similar to the effects of poison ivy. The skin reaction is known as photo-dermatitis and can occur after 48 hours of having contact with the sap. Besides being a health risk to humans, the weed can also damage gardens by delaying and disrupting the growth of plants.
Put on latex gloves, goggles, ski mask a long shirt and pants before trying to eliminate the hogweed. To avoid a reaction, make sure that your skin does not come in contact with the plant.
Use a sharp knife to cut the flowers a least 3/4 inch below the bud. Dispose of the flower carefully into a plastic bag and make sure not to let any seeds fall off the ovary of the flower.
Dig up all of the roots from the weeds using a small garden shovel and dispose of them. Also, make sure that roots don't come into contact with any other plants as you uproot them. It may help to slightly moisten the soil when uprooting.
Spray a post-emergent herbicide over the area where the weeds were. Make sure the herbicide contains glyphosate and try not to spray any of area then the soil where the roots were. Once finished, make sure to wash all your clothes so that no sap spreads.
Contact a lawn care specialist to remove the hogweeds for severe cases that could be extremely dangerous, such as large weeds that have spread on the side of your house. If you're not comfortable removing the weeds yourself, find a company that specializes in weed removal.