Information on weed identification and control, including catsear, marestail, purple loosestrife, pokeweed, pigweed, poison ivy, crabgrass, hemlock, purslane and multiflora rose. Tips on various herbicides and integrated pest management.
Tree-of-heaven (Ailanthus altissima) also known as ailanthus, Chinese sumac, and stinking sumac is a rapidly growing, deciduous tree native to a region extending from China south to Australia.
Japanese barberry (Berberis thunbergii) was introduced from Japan around 1875. It now ranges from Nova Scotia south to North Carolina, and westward to Montana.
Japanese knotweed (Polygonium cuspidatum) and Giant knotweed (Polygonum sachalinensis) are two invasive, exotic weeds found throughout much of the United States and Canada.
By David R. Jackson, James Finley, Ph.D.
Dense understories of hay-scented, New York, and bracken fern can interfere with the regeneration of hardwood forests, threatening their sustainability.
Autumn olive (Elaeagnus umbellata) is an exotic deciduous shrub and has been listed as a noxious weed throughout much of its range.