The reaction can be a special problem for children because the plant's hollow stems are perfect for children who make imitation blow-pipes and telescopes out of them, Brendley said. That's means the very real possibility of painful or, disfiguring skin reactions around the mouth or eyes of the child, he said. When autumn comes around and the seeds have been sown, the plant dies back to an almost dried flower look and 5 foot to 13 foot tall thick, hollow stems that are ribbed and may be 2-4 inches in diameter. Brendley said the hogweed begins in spring with a vegetative or herbaceous period, when it is mostly green leaves growing close to the ground. The plant then begins to produce white flowers, in clusters that can be as much as a yard or so in diameter atop a hollow stem that is 2-4 inches in diameter.
Seeds eventually form and fall off or are blown by the wind and the process starts all over.
The hogweed is a relative of the carrot and it produces a large, tuberous root that is very difficult to dislodge. I was down a foot in the soil and I couldn't get the root out. It was thick , maybe more than an inch in diameter. Since the plant may grow by sending up shoots from the root every spring, the difficulty in getting rid of the root means difficulty in getting rid of the hogweed. The stand of the weed on Hershey Road was sprayed with Roundup the recommended herbicide for hogweed.