Invasive Species in Pelham

For sightings on town-owned conservation land, notify the Community Trail Coalition through the Pelham Pathways Trail Report form. This keeps local volunteers & town managers informed and lets state experts review reports as needed.

Protecting Our Forests, Meadows & Wildlife Habitat

Take a walk through Pelham. You may hear a songbird, spot a butterfly, or see a frog near a wetland. Our forests, meadows, young grasslands, shrublands, and wetlands give these animals—and many other species of conservation concern—food and shelter. They also give people of every age and ability wonderful places to explore.

But some unwelcome guests are moving in. Certain plants and insects from other parts of the world can spread quickly and harm these special places. Here is the good news: you can help! Learn what to watch for, report what you spot, and support careful efforts to protect the land. Let’s start with two visitors already seen at Pelham Veterans Memorial Park: tree-of-heaven and the spotted lanternfly.

What makes a species “invasive”?

Not every plant or insect from another country is a problem. An invasive species is a non-native living thing that causes—or is likely to cause—harm to nature, our economy, or human health. New Hampshire law defines invasive plants in RSA 430:52, VII.

Picture a patch of native wildflowers slowly disappearing beneath a thick tangle of new shrubs. That can happen when invasive plants take over. They can crowd out wildflowers and young trees, change soil conditions, slow forest regrowth, block wildlife movement, and leave fewer places for birds, bees, and other creatures to find food and shelter. Over time, the landscape itself can change.

Pelham Pathways supports education and responsible care of the land, guided by specialists at UNH Extension, New Hampshire Fish and Game, the NH Natural Heritage Bureau, and other trusted organizations.

Meet two unwelcome visitors

Tree-of-heaven: A tree that won’t give up

Tree-of-heaven (Ailanthus altissima) grows fast and spreads both by seed and through its roots. Soon, one tree can become a crowded patch that pushes out native plants. It is also a favorite feeding and host tree for spotted lanternflies, although those insects feed on many kinds of plants.

Nature detective clue: Look for very long leaves made up of many smaller leaflets. Their edges are mostly smooth, with tiny gland-like teeth near the base. Native sumac and black walnut can look similar, so check several features with a reliable guide before deciding what you have found.

This tree has been confirmed at Pelham Veterans Memorial Park. A resident reported it, and New Hampshire invasive species coordinator Douglas Cygan checked and verified the identification.

Important: Please do not simply cut it down! Cutting a mature tree-of-heaven can cause lots of new shoots to pop up from its roots. A trained invasive-plant professional can help plan the right treatment and timing. Never cut or treat a tree on public land without permission.

Spotted lanternfly: Beautiful colors, big trouble

The spotted lanternfly (Lycorma delicatula) may look striking, but it is an invasive insect that feeds on plant sap. It can feed on many plants and is a special worry for grapevines. Large numbers can weaken plants. They also leave sticky “honeydew,” which can lead to black sooty mold. The good news for people and pets: lanternflies do not bite or sting.

Nature detective clues: Adults have gray front wings with black spots. When they open their wings, you may see flashes of red, black, and white. Young insects, called nymphs, are black with white spots; older nymphs also have red. Egg masses can look like dull gray smears of dried mud stuck to trees, rocks, trailers, cars, patio furniture, or equipment. Those eggs can survive winter and hatch in spring.

Pelham update—October 2026: Two spotted lanternflies were seen at Pelham Veterans Memorial Park: one on tree-of-heaven and one on a wild grape leaf. Both sightings were reported to the state. An October 22 update from a state entomologist described sightings in Pelham and nearby towns, along with continued survey work. Seeing a lanternfly does not, by itself, mean a breeding population lives here. Visit NHBugs.org for the latest confirmed information.

Watch for hitchhikers! Lanternflies and their eggs can travel on cars, trailers, outdoor furniture, and tools. Check these items before moving them, especially after visiting an affected area. If you see a suspicious insect or egg mass, take a picture and follow NHBugs guidance for reporting and handling it.

Be a nature detective: See it? Report it!

You do not need to know every plant or insect by name. When something looks suspicious, we would much rather have you report it than stay silent because you are unsure. Experts can help check the sighting.

• Take a clear photo. For a plant, include the whole plant plus close-ups of leaves and stems. For an insect, try to capture its markings or egg mass.
• Write down when and where you saw it. Include the date, trail or conservation area, a nearby landmark or GPS location, and how many you saw.
• Report suspected invasive insects, including spotted lanternflies, through NHBugs: https://www.nhbugs.org/reporting-form
• Report suspected invasive plants through EDDMapS: https://www.eddmaps.org
• If you found it on public land, also let the responsible land manager know when appropriate. A report helps guide an assessment, but it does not promise immediate removal or treatment.

Please leave suspected invasive plants where they are. Pulling, digging, cutting, or moving them without a plan can spread seeds or pieces of roots and stems. When in doubt, photograph and report!

Invasive plants to know: Meet the usual suspects

These are useful plants to recognize. Do not assume one is established at a specific Pelham site until its identity and location have been checked. Some native plants look surprisingly similar, so compare good identification guides—and report a suspected sighting even if you are uncertain.

• Japanese barberry (Berberis thunbergii): A thorny shrub with small oval leaves and red berries. It can grow into thick patches that crowd out native plants.
• Oriental bittersweet (Celastrus orbiculatus): A climbing vine that wraps around trees and shrubs and can damage them. Its colorful berries spread seeds, so do not use berry-covered vines for holiday decorations.
• Japanese knotweed (Reynoutria japonica): A tall plant with hollow, jointed stems. It can form large patches, and even small pieces of stems or roots may grow into new plants. Handle it with great care.
• Multiflora rose (Rosa multiflora): A thorny shrub with long, arching branches that can make thick, hard-to-cross tangles.
• Glossy buckthorn (Frangula alnus) and common buckthorn (Rhamnus cathartica): Shrubs or small trees that can crowd out native growth. Check carefully for native look-alikes.
• Burning bush (Euonymus alatus): A landscaping shrub famous for its bright red fall leaves. It can escape yards and spread into natural areas.
• Tree-of-heaven (Ailanthus altissima): The fast-spreading tree described above—and a favored host for spotted lanternflies.

How do we manage invasive plants without harming what we love?

There is no one-size-fits-all answer. The best plan depends on the plant, where it grows, the time of year, how large the patch is, and the wildlife and native plants nearby. First identify the plant. Next set a goal, figure out safe disposal, and plan how to check for new growth afterward. Often, success takes more than one method and several follow-up visits.

On public land, never pull, cut, mow, dig, or use herbicides without permission from the land manager. Special rules or permits may apply near water and wetlands.

Pulling and digging

Some small barberry, buckthorn, or bittersweet seedlings can sometimes be removed by hand or dug up when the ground is moist. The goal is to remove roots while disturbing as little soil as possible. Identify the plant first and ask how to handle and dispose of it; some seeds, roots, and stems can spread or regrow. Follow current UNH Extension advice and the landowner’s instructions.

Cutting and covering

For some woody shrubs, cutting close to the ground and covering the stump may be part of a carefully planned project. Buckthorn, multiflora rose, and burning bush may each need different treatment. Covers must stay secured and be checked for regrowth for as long as a specialist recommends—sometimes a year or more. This is NOT a general solution for tree-of-heaven.

Smothering stubborn knotweed

Sometimes a strong, UV-resistant cover can block light and help control an invasive patch. But it can also kill native plants underneath. Japanese knotweed is especially stubborn: some projects need five full years of carefully maintained covering, followed by more checks. Smothering is one possible tool, not a quick fix or something every site needs. Do not mow, rototill, or move knotweed pieces without a specialist-approved plan.

Carefully targeted herbicides

Sometimes a targeted herbicide can be one part of a larger plan, particularly for difficult knotweed or bittersweet patches. The decision must consider the plant, season, water nearby, and risks to people, pollinators, and wildlife. Professionals must follow product labels, New Hampshire rules, and any needed licenses or permits. Work on public land requires the land manager’s approval. Broad or unnecessary spraying should be avoided.

What about mowing?

Mowing can keep trails open and, in selected places, help manage certain invasive plants over time. But mowing by itself usually will not get rid of an established patch: buckthorn, bittersweet, and knotweed may grow right back. Timing matters!

Mowing without a plan can also remove native flowers, grasses, and shrubs that birds and pollinators need, take away shelter for frogs and small mammals, and harm meadows used by sensitive wildlife. Mowers can carry seeds and plant fragments to new places. Before mowing, identify what is growing, consider a habitat assessment, avoid needless off-trail cutting, and clean tools, shoes, and equipment between sites—especially near wetlands.

Keep watching: Prevention and monitoring

A good report today can prevent a much bigger problem tomorrow. Observations from Pelham’s protected land—including Merriam Farm Conservation Area, home of Virginia’s All Persons Trail—can help managers decide which places need attention first.

With permission and training, volunteers may record the plant species, location, how much is growing, how sensitive the habitat is, and what action might be needed. The land manager can then review the information. Everyone can help prevent spread by cleaning tools and equipment and avoiding the movement of seeds, plant pieces, or contaminated soil.

Why Pelham needs an Invasive Species Management Plan

Imagine noticing an unfamiliar vine beside your favorite trail. A year later, it has climbed nearby shrubs and young trees. Who should be notified? Which areas need attention first? How can we help without accidentally making the problem worse?

An Invasive Species Management Plan would help Pelham answer those questions—and turn individual observations into coordinated action.

Our parks, trails, forests, meadows, and wetlands are connected. Invasive plants can spread across property boundaries, and seeds or plant fragments can travel on footwear, tools, and equipment. Caring for these places takes shared information, clear responsibilities, and a commitment to follow-up.

The identification of tree-of-heaven at Pelham Veterans Memorial Park offers a local example of why planning matters. Different species need different approaches, and an action that seems helpful—such as cutting a tree—can sometimes encourage more growth.

A practical plan would help Pelham:

• Know what is growing where. Identify and map invasive species, with expert help to verify uncertain findings.
• Choose priorities wisely. Address emerging problems and protect valuable habitat while making thoughtful use of available funding and volunteer time.
• Coordinate the work. Clarify roles for town boards, departments, land managers, specialists, community organizations, and volunteers.
• Match the response to the site. Choose appropriate methods, obtain permissions, and use qualified professionals when needed.
• Keep checking. Plan for regrowth, evaluate results, and restore native vegetation where appropriate.
• Help residents take part. Offer clear guidance on identification, reporting, preventing spread, and approved volunteer opportunities.

In 2027, Pelham Pathways’ Community Trail Coalition will advocate for a town-wide Invasive Species Management Plan. We hope to encourage collaboration among the people and organizations caring for Pelham’s land, with guidance from knowledgeable specialists.

A plan would give our community a practical way to begin, set achievable goals, and sustain progress over time. Together, we can help protect the living landscape around the trails we love.

Need photo of a beautiful local landscape photo: it would connect the planning goal to a place residents recognize and care about.

Learn, volunteer, and make a difference

Imagine joining a guided walk where someone shows you how to spot bittersweet, or helping care for a trail you love. Pelham Pathways and its Community Trail Coalition support education and are exploring identification walks, trailhead and kiosk displays, volunteer training, small targeted workdays, and helpful online and printed materials for homeowners. An invasive-species learning and removal day, as well as trail or meadow care projects, may also be considered.

These are ideas being explored, not events already on the calendar. Activities will be announced when plans are ready and coordinated with landowners and managers. Look at the Pelham Pathways Events Calendar or email PelhamPathways@gmail.com to learn about opportunities.

Six easy ways to help Pelham

• Learn to recognize just one invasive plant or insect, then share what you learned with a neighbor.
• Report what you see, and join an announced, approved workday or identification walk if you can.
• Ask how you might help care for or monitor a trail section or meadow.
• Choose native trees, shrubs, and flowers at home to feed and shelter wildlife.
• Avoid unnecessary mowing off trails. Check outdoor items for hitchhiking insects, and clean your equipment after use.
• Support careful, plant-by-plant decisions and teamwork among the groups caring for Pelham’s land.

Working together for Pelham

Protecting nature is a team effort. Pelham Pathways values working with land managers and partners, including the Forestry Committee and Conservation Commission. As we learn more, our methods can improve, too. We share the same hopes: healthy forests and meadows, safe trails for everyone, fewer invasive species over time, and decisions based on the best available science.

Learn more and report sightings

• NHBugs.org — spotted lanternfly identification and current updates
• NHBugs.org/reporting-form — reporting suspected invasive insects
• EDDMapS.org — reporting suspected invasive plants
• Penn State Extension — tree-of-heaven identification and management
• UNH Extension — mechanical control of invasive plants
• Picking Our Battles: A Guide to Planning Successful Invasive Plant Management Projects
• UNH Extension, Nature in Your Backyard — including Matt Tarr’s herbicide-free knotweed case study
• Nature Groupie — stewardship tool libraries
• UNH Extension — invasive species information and resources

Last reviewed: October 2026. Local reports and official status can change. Check NHBugs.org for the latest confirmed insect information.

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