Herbicide Use

By Jeff Stann

Removing invasive plants at Mitchell Field in 2017. After cutting, stems were painted with an herbicide (Becky Gallery photo)

Removing invasive plants by pulling and digging is the preferred way when practicable. But sometimes plants get too large to handle that way, or it may be destructive of nearby plants. This is an appropriate time to think of herbicides as alternative method.

Large woody vines like Asiatic Bittersweet and large shrubs like Japanese Barberry, shrub Honeysuckles, Autumn Olive and Multiflora Rose can be controlled with minimal environmental disturbance with Glyphosate (sold under such names as Roundup). Cut the stem or stems close to the ground, then apply concentrated (20-25%) Glyphosate directly onto the cut stem with a paint brush or small spray bottle. The best time to do this is from late August through the autumn, as long as temperatures are above 40 degrees. The glyphosate should be applied immediately after cutting. This method avoids widespread spraying and attacks the plant when it is drawing resources down into its roots for winter. But remember that no herbicide can be applied in Harpswell within 25 feet of the water.

If the plants have fruit or seeds, it’s best to cut up and bag the entire plant. If the size of the plants prevents bagging, you can pile them into one area where they can be monitored for re-spouting. Covering them with a tarp will prevent birds taking the seeds and broadcasting them.

Before you consider using herbicides in Harpswell, please read the Harpswell ordinance on pesticides. Click here for more information.