In the Portland area, a regional government called Metro is in charge of managing some 14,000 acres of wilderness, including Oxbow Regional Park, Smith and Bybee Wetlands, Mount Talbert, and a number of other newly acquired parks that are not yet open to the public. When I heard that Metro uses herbicides in its parks, I became concerned about the safety risks to foragers and herbalists who may be wildcrafting unawares.
I called Dan Moeller, the Natural Areas Land Manager at Metro, who is responsible for overseeing management of invasive species, including herbicides. He told me that Metro sprays in the spring and the fall, and that when it does, employees post signs, staked into the ground, at the entrance points to the wilderness areas. “We post all areas that have herbicide applications for the period of time that the chemical is active and toxic to humans,” Dan said.
They also use a blue dye to stain the plants. He said targeted species include holly, ivy, knotweed, clematis, tansy ragwort, Himalayan blackberry, garlic mustard, scot’s broom and hawthorn. Generally, he said, the plants will wilt very quickly, so in addition to a blue tinge you would see that they look unwell.
Explaining the method of application, Dan told me, “We don’t spray a tree of hawthorn. We would cut it off at the stump and then, with a sponge, dab directly onto the stump.”
The chemical Metro uses most is glyphosate. That is the most widely used pesticide in America, and one of the ingredients in Monsanto’s Round-Up. Metro also uses triclopyr. Both are considered low-toxicity compared to other chemicals, and in some reports are said never to have resulted in human hospitalization due to exposure.
“All the chemicals we use have been approved by Salmon Safe and heavily vetted by different agencies to make sure there’s no effect on fisheries and water systems,” Dan said. “For the most part, if these chemicals are applied and they’re dry, they come to the point where you would have to ingest an insane amount of it to get sick.”
I’ll continue to learn more about these chemicals, and I encourage you to do the same.
Of course, harvesting wild plants is technically not allowed in Metro parks without an expensive permit ($105), unless you’re taking small quantities of berries or nuts. That said, Dan said he encourages anyone who wants to take out invasives by hand to call him and talk, at (503) 797-1545.
Please share this information with anyone who harvests wild plants in the Portland Metro area.