The August 9 Enterprise (Page 3) reported a $400K estimate for eradicating knotweed from the Little Pond conservation land—once established, it is expensive to control this invasive plant! Falmouth’s bike path, many roadsides, and some private properties are being colonized by Japanese Knotweed. This almost-unkillable perennial grows in sandy soil in light or shade, forms large dense stands (over eight feet), overshadowing other plants (Google it to see photos). Roots spread up to 30 feet; its taproot, many feet deep, stores energy, enabling it to re-sprout repeatedly after cutting. Sunlit larger stands began flowering on about August 25; however, knotweed spreads primarily not by seeds, but via shallowly buried, chopped-up fragments from roadside mowing or other disturbances, likely largely human induced. Small outbreaks are spreading inside the gate at 650 Gifford Street, as are extensive infestations north of the Brick Kiln/Sandwich Road intersection, apparently extending into adjacent lot(s). In town, an established stand is near the library at the “T” of Katharine Lee Bates and Gifford streets. It is at many other sites.
Expense will obviously prevent Falmouth from removing large stands faster than new ones form if it goes unchecked, especially since glyphosate (Roundup™) use is now banned on town land (roadsides). Falmouth homeowners thus seem on their own, aided by any anti-spreading practices that DPW may implement. Its erratic mode of spreading and rapid growth make it a neighborhood issue. To control it, we suggest (1) locate and (2) then weaken or eradicate smallish new outbreaks, possibly after consulting more experienced local experts. Survey your neighborhood by walking a few hundred feet in every direction (smaller plants are invisible to drivers), noting controllable ones (roughly 1-20 stalks, inches to four feet high). If finding knotweed, you might alert those closest, recruit concerned neighbors, or treat it yourself. Step (2) removal: caution—avoid creating or scattering fragments! Cut stalks close to the ground, bagging immediately. Recheck treated sites late the next spring It needs cutting for two to four years, each year becoming easier.
If few act, in multiple neighborhoods knotweed seems likely to threaten property values and even to alter the town’s character. Parts of Falmouth will likely succumb in the coming decade to knotweed, but others may, by luck or effort, remain pristine. Which will yours be?
Marsha and Oliver Zafiriou