FALMOUTH — Bob Shafto grins with satisfaction as he drives down Blackstrap Road, past tangles of dead, brown plants along the roadside.

Until last year, the plants, foreign multiflora rose bushes and stands of bamboo-like Japanese knotweed, were growing strong, spreading and choking out native species. That was before the town started a targeted herbicide program to stop the invaders.

Invasive species watch list

The state considers 19 terrestrial and aquatic plants to be invasive. Here are some of the most problematic:

Multiflora rose

Multiflora rose/rambler rose

Appearance: thorny arching stems with white and pink flowers blooming in June and July

Native to: eastern Asia

Asiatic bittersweet

Appearance: climbing vine with oval leaves and brown branches

Native to: eastern Asia

Japanese barberry

Japanese barberry

Appearance: dense, woody shrub with spiny branches and red berries, turns red and orange in the fall

Native to: Asia

Autumn olive

Appearance: large shrub that can grow up to 20 feet tall, silvery leaves, yellow tubular flowers, abundant pink berries.

Native to: eastern Asia

Japanese knotweed/Mexican bamboo

Appearance: thick stands of 3- to 6-foot-tall plants with broad oval leaves and tiny greenish-white flowers

Native to: eastern Asia

Common buckthorn

Common buckthorn/glossy buckthorn

Appearance: large shrub that grows as tall as 20 feet, oval leaves with fine teeth, twigs with sharp thorns, small clusters of greenish-yellow flowers and berries

Native to: Europe, west Asia, Africa

Morrow honeysuckle

Tartarian, Morrow, Belle’s honeysuckle

Appearance: shrub can grow up to 16 feet tall, wide branches with oval and oblong leaves and tubular flowers sprouting in pairs.

Native to: Russia, Japan

Source: University of Maine Cooperative Extension

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“This is an invasive species war zone,” said Shafto, the town’s open space ombudsman and one of a handful of town volunteers licensed to use pesticides against invasive plants.

Falmouth is at the forefront of efforts to reverse the spread of invasive plants in Maine. In the past five years the town has beaten back infestations on public land, and it is now in the second year of a program to kill roadside invasives by spraying them with a 2 percent glyphosate solution. Glyphosate is a common herbicide that is sold under the brand name Roundup.

The town also is targeting invasives growing on private property. In addition to workshops to educate residents about invasive plants, Falmouth’s conservation commission is considering ordinances that would prohibit the sale and distribution of invasive species and require that new developments and subdivision roads remove unwanted plants in order to be certified as invasive-free.

Falmouth officials hope to blaze a trail for other communities, land trusts and property managers by bringing attention to threats from land-based invasive plants, which have received less attention than invasive aquatic plants such as milfoil.

“People are less aware of the impact they are having on our natural ecosystems, which are profound,” Shafto said.

A CREEPING PROBLEM

There are 19 plant species in Maine considered invasive and almost 30 others that are probably invasive, according to the Maine Natural Areas Program, a branch of the Department of Agriculture, Conservation and Forestry. Invasives include Japanese barberry, autumn olive, buckthorn, bittersweet, and two varieties of honeysuckle.

Some non-native plants have been in Maine for more than a century. Many were imported for ornamental gardens and spread from the original planting. Through the mid-20th century, the U.S. Department of Agriculture even recommended planting some species for erosion control.

But without native competitors or diseases to keep them in check, invasive plants thrive and spread aggressively, choking out native species and harming sensitive ecosystems.

Road construction and development disturb the soil and open up virgin territory, aiding the spread of invasives. The sides of highways and other major roads are loaded with non-native plants, some creeping onto guardrails and overgrowing full-size trees.

“When they take hold, there is nothing that is keeping them at bay. That is one of the competitive advantages that make it so easy to spread,” said Kristen Puryear, a state ecologist.

Invasives may also pose a public health risk. Researchers at University of Connecticut have linked Japanese barberry to increased prevalence of Lyme disease, because the plant creates a microclimate favorable to the survival of black-legged ticks that carry the disease. Scientists in Missouri found that white-tail deer preferred areas of invasive honeysuckle, resulting in higher population of lone star ticks that can carry diseases.

TAKING ON INVASIVES

When Falmouth started its campaign five years ago, the River Point Conservation Area was overrun with multiflora rose. Touring the area this week, Shafto said that roughly 95 percent of invasives had been cleared from the property.

“This is what we want our lands to look like,” he said, pointing to areas previously choked with foreign plants.

In the nearby town forest, dozens of skeletal brown bushes are all that is left of an intense honeysuckle infestation. Over the course of the program, Shafto and two licensed master pesticide applicators have destroyed thousands of plants in town.

“I’m a herbicidal maniac,” Shafto joked.

Beginning last year, Falmouth took the program a step further, hiring a specialist to treat 200 roadside properties in West Falmouth where invasives had been identified. In the aftermath of that campaign, the town is planning another spray operation on 140 properties in middle Falmouth this year.

While the town can only spray in its right-of-way, landowners can pay extra for treatment on their property. For notoriously pernicious knotweed, however, Falmouth will pay the tab for treatment on private property. The town is continuing its outreach efforts, hosting a workshop at the Lunt Auditorium next Tuesday.

Falmouth already prohibits the planting of invasives in development landscaping, but the conservation commission is planning new ordinance language to prohibit the sale of invasive plants in town and require developers to clear land of invasives to get project approvals. Shafto said the commission hopes to bring ordinance language to the Town Council for consideration by the end of the year.

FOCUS ON PLANT CONTROL

More communities and land conservation groups also are taking aim at invasives as the plants have crept from roadsides deeper into woodlands and protected areas.

“There’s a lot more interest when it moves away from disturbed areas and into areas we would consider wild,” said Maine state horticulturist Gary Fish.

The Maine Island Trail Association is working on a control plan for the properties it manages, including Little Chebeague Island. Portland’s Cliff Island has been trying to control invasives for years. Cape Elizabeth is tackling multiple invasive species at its popular Fort Williams Park, the Harpswell Heritage Land Trust and Yarmouth Conservation Commission have invasive control plans, and the town of Cumberland plans a spraying program this year in Broad Cove Preserve and the town forest to fight a roughly-30 acre patch of invasive buckthorn.

While it may be impossible to rid an area of the plants once they take hold, the efforts can contain them.

“We’re not kidding ourselves to think we can get rid of it all,” said Cumberland Town Manager Bill Shane. “Eradication is a fairy tale.”

Erno Bonebakker, a volunteer for the Maine Island Trails Association and member of Casco Bay Invasive Species Network, said the network recently published a plant management guide to help land stewards confronting invasives.

“Land managers not familiar with plants might just throw up their hands with dismay and say it is too big of a problem,” Bonebakker said. “The thrust of the booklet is you can manage any size property at any level of infestation.”

STATE TAKES ACTION

Nearby states, including New Hampshire and Massachusetts, have banned the sale and distribution of invasive species. Maine prohibits distributing aquatic invasives, but does not have a ban on terrestrial invasive plants, although a state working group has a draft list of more than 30 species that might be subject to stronger regulation.

Chad Skillin, head of landscape design for Skillins Greenhouses in Falmouth, said most of the species of concern haven’t been available from suppliers for 10 years.

“With increasing numbers in the past 10 years, people are looking for things to be native and less invasive,” Skillin said.

But, even if local nurseries aren’t selling plants, a property owner who wants an imported plant can find whatever they want by shopping online.

“I can go on the internet, look for a minute and a half, order a plant from New Zealand and have it in my backyard in five days,” said Dale Pierson, who owns Pierson Nurseries in Biddeford.

CORRECTION: This story was updated at 11:07 a.m. on June 28 to correct the name of Dale Pierson.

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