Whether dealing with large-scale landowners or backyard gardeners, they try to convey the principles of integrated pest management, or IPM — “using a variety of tools and methods to control an undesirable organism,” Dr. Mangold said. “Which, in our case, means plants that are weeds.”
The IPM decision-making process that precedes any action aims to determine the least toxic solution possible to achieve tolerable levels of pest pressure, whether from weeds, insects or animals.
And if an herbicide proves to be part of a weed solution, “it’s all about maximizing the benefit while minimizing the risk,” Ms. Orloff said. “Because using any herbicide, organic or synthetic, has some level of risk.”
She and Dr. Mangold suggested that anyone tackling weeds get into the IPM mind-set by asking themselves several questions.
Do you know what the undesirable plant is? Without proper identification, it’s impossible to know the plant’s life cycle, including whether it is annual or perennial, which will inform any control strategy.
Do you have a weed that is susceptible to the treatment under consideration, and is it at the right life stage for effective treatment? Horticultural vinegar, for example, is recommended for use on young annuals that have four or fewer true leaves, not on established ones or on perennials that may suffer foliage damage but are likely to resprout from their roots.
With poison ivy or a deep-rooted perennial invasive like field bindweed (Convolvulus arvensis), Ms. Orloff said, “you might have to spray horticultural vinegar every two weeks for five years — not a feasible plan.”