This column has profiled an Invasive Plant of the Month since last October, providing season-specific information about seven damaging invasive plants that proliferate in town. This month covers summer strategies for gaining control over invasive plants and describes some key resources.
Pull by the roots
Removing invasive plants by pulling them up by the roots is a great control method, especially if the plants are discarded so there is no chance of re-rooting. Purple loosestrife, garlic mustard, young Japanese bittersweet, young multiflora rose, Japanese barberry, mugwort and young autumn olive can be controlled this way before they establish permanent residency.
Stop the flowers
Flowering plants, even established shrubs, weaken over time when they are prevented from flowering. Multiflora roses that grew in the field paths at Holcomb Farm have disappeared as a result of frequent mowing by volunteers over several years. Where invasive plant concentrations are too dense, such as Japanese barberry, it is a step forward to cut them at the base before they are able to flower and set seeds. Weed-whack garlic mustard, Japanese knotweed and mugwort several times a year to prevent them from flowering; dispose of the cuttings so that they do not re-root.
Cut … and return
Shrubs and trees strangled by Japanese bittersweet and multiflora rose can be saved by cutting the invasives as close to the ground as possible. Over a year’s time, most of the cut vines above will rot and fall or can be pulled down. But because cutting stimulates vigorous new growth, it’s necessary to repeat cutting at least annually. Mature plants that cannot be dug up are good candidates for careful cut-and-paint use of liquid herbicides.
Take the long view
It’s easy to get discouraged when tackling invasive plants—their vigor and resilience are keys to their success. It may be unrealistic to expect to eradicate an entire invasive plant population in a year. But we can restore the natural beneficial balance that prevailed before humans introduced invasives by returning to the effort repeatedly over time, using proven strategies and lots of elbow grease.
CT Invasive Plant Working Group is the state’s central information hub. CIPWG’s Meet the Plants list includes information about growth habits, state law status, and links to many resources for each plant. The group sponsors events, offers speakers, and maintains a listserv (cipwg.uconn.edu).
The Connecticut Forest and Park Association offers a vast array of information about the state’s forests and lands, and strategies to maintain them. This page includes a focus on invasive plants and alternatives:
Eat the Invaders promotes ways to benefit from invasive species—plants and animals. It includes recipes and information about their nutritional value. (eattheinvaders.org/)
For more information on invasive plants in Granby, see a new site coming online in July. (granbyinvasiveplants.weebly.com)