By: Anthony Trimboli Background Poison hemlock (Conium maculatum) is an invasive weed that is found throughout the United States. It is commonly seen growing along roadsides, in ditches, and other disturbed areas with moist soils. Poison hemlock grows as a biennial in the colder portions of the U.S. That simply means that the first year … Continue reading Best Times to Kill Poison Hemlock: Winter and Early Spring