This invasive plant could damage the foundation of your home

When construction began in their Saugus neighborhood more than a decade ago, couple Bob and Rosanne Maher slowly began to notice a weed growing on their property. Now they’re asking the city for help.

But Japanese knotweed is not just a weed. It is a fast-growing invasive plant that, when left unchecked, grows quickly, tall, deep and large. Bob said they used chemicals to kill it, placed tarps to starve it and tried to pull it up from its root.

“It’s hard to get rid of,” Bob told Boston.com.

The Mahers addressed the Saugus Planning Board last month to urge the city to help contain the plant. Currently, grass is encroaching on their Fiske Avenue home, where they have lived for more than two decades.

This relentless weed has already invaded their neighbor’s property and is threatening nearby wetlands. Rosanne told Planning Board members they have spent hundreds of dollars to get knotweed under control.

“If we ever have to sell our house, this is something we will have to address,” she said. “They wouldn’t necessarily want to buy the house because it’s very difficult to get rid of.”

Japanese knotweed has large, heart-shaped leaves and hollow, bamboo-like stems. It grows in dense clumps and produces cream-colored flowers in August.

Knotweed’s rhizomes burrow up to 10 feet deep, and its side cover can reach 40 feet underground. It takes years of work to completely eliminate it, and the plant must be disposed of properly to prevent further spread.

Last year, a family won $300,000 from a developer they claimed had spread weed in their yard.

“It can push through the sidewalk”

The weed is widespread in the Nashua River watershed near Groton, a watershed scientist said. Groton has its own Invasive Species Committee with volunteers working to educate and eradicate plants locally. Jonathan Basch, co-chair of the committee, said they had successfully reduced Japanese knotweed, while using less herbicides.

Basch said injecting herbicide directly into the stem at the right time of year is effective in killing the plant.

“It can become a really big problem over time, and because it grows so densely, it can become a foundation,” Basch said. “It can push through the sidewalk.”

Indigenous group seeks to restore knotweed lands

A Native-led conservation group wants knotweed gone from Wampanoag common lands — a 32.4-acre donation and former summer camp in Kingston. The Native Land Conservancy works to restore the land as the Wampanoag would have experienced it hundreds of years ago.

“As the Wampanoag have a millennia-old relationship with this land, we are in it for the long haul,” said NLC Executive Director Diana Ruiz. “We’re not going to rush things to get it done sooner.”

Ruiz said they were battling two stubborn patches of knotweed on Wampanoag common land. She explained that the old summer camp buildings were demolished when they were donated to the project.

“With this disturbance, there are all these open ecological niches that are there and that makes the time ripe for invasive plants to take over,” she said.

Ruiz said they cut down a plot and covered it with a thick, heavy tarp to prevent photosynthesis. The plant stores energy in the soil and can even penetrate sunlight.

“It’s not the prettiest strategy, but it’s a way to not use chemicals, prevent the spread, and as a bonus, the garter snakes seem to like living under the tarp,” Ruiz said.

Another patch of Japanese knotweed is along Muddy Pond — a healthy patch, Ruiz said, that will take longer to weaken.

“We slowly deplete these underground resources, digging up the rhizomes, starting at the outer edges of the plot, while introducing soil stabilizing plants and plants that could shade and outcompete the knotweed patch or at least control it while we work slowly. get it back,” she said.

The Mahers said Saugus officials are doing their best to combat the rapid spread of weeds, which they say were introduced in soil brought in by construction workers.

“You want to take care of your home. You want to spend time with your family and everything else,” Bob said. “Every time you go out to mow your lawn, you think, ‘It’s back.’