Newtown Knotweed Initiative

10/16/2026

A BIG thank you to Newtown PW for not mowing the treated knotweed close to the intersection of Wasserman Way and Mile Hill Rd S. Something to look forward to is a less vigorous stand next year which will keep our sight lines safe and clear!

09/12/2026

Checks and balances.

Spotted lanternflies, meet your match.

GLI reader and wildlife photographer Lesley Husband captured this remarkable image of a praying mantis making a meal out of one of these invasive insects in Neptune Township, N.J. See below for more mantis-in-action photos and videos from readers. 👇

Spotted lanternflies began arriving across Long Island in massive numbers in 2024, and we’ve already documented yellowjackets feasting on them. Now, photos of mantises devouring lanternflies are pouring in from readers across the region.

09/03/2026

Did you know that spotted lanternfly (SLF) can complete its lifecycle without tree of heaven?

And while some report that birds may eat them, research is showing that SLF that fed on tree of heaven are less palatable to birds than those who have not, due to a defensive chemical tree of heaven produces called quassinoids.

Two invasive species from China found each other in Pennsylvania 200 years apart. Tree-of-heaven arrived in the 1780s as a garden ornamental. It spread across the eastern United States unchecked, growing in vacant lots, highway medians, cracked sidewalks, and forest edges from Maine to Georgia. Cutting one down can make the problem worse by triggering new shoots from an underground root system that may send suckers up 50 feet from the original trunk. Today it occurs in more than 40 states.

Then, in 2014, Pennsylvania officials found an insect they had never recorded in the United States before. Spotted lanternflies were feeding on tree-of-heaven in Berks County. Old egg masses suggested the population had probably been there for at least a year or two before anyone noticed it, and one heavily infested property was a specialty stone business, consistent with the insect arriving as an unnoticed hitchhiker on imported goods.

Lanternflies are hardly picky. In North America they have been recorded using more than 100 plant species, including grapes, maples, walnuts and fruit trees. They can even complete their life cycle without tree-of-heaven. Given a choice, however, tree-of-heaven remains their preferred host, and removing it from their diet has been associated with reduced fitness.

The connection goes deeper than food. Tree-of-heaven produces bitter defensive chemicals called quassinoids. Lanternflies feeding on the tree can take some of those compounds into their own bodies. Researchers in Asia first showed that birds avoided lanternflies carrying those chemicals, and a 2025 Penn State study tested the same effect with American birds. House wrens ate fewer lanternfly nymphs that had fed on tree-of-heaven than nymphs raised without it. In another experiment, wild birds pecked less often at suet containing adult lanternflies that had eaten tree-of-heaven.

The insect has proved equally good at using the modern landscape. Females glue egg masses to far more than trees. Vehicles, trailers, grills, outdoor furniture, bicycles, firewood, stone and other hard surfaces can carry them. The U.S. Fish and Wildlife Service noted that the early east-to-west spread across Pennsylvania closely followed the Pennsylvania Turnpike, probably because people were unknowingly moving the insects or their eggs. By 2025, established populations had been recorded in 19 states and Washington, D.C.

Grapevines have been among the hardest-hit crops. Large lanternfly aggregations repeatedly drain sap, and poorly controlled infestations have caused serious vine decline and sometimes complete plant loss. A Penn State economic analysis estimated that spotted lanternfly was already associated with about $50 million a year in economic losses in southeastern Pennsylvania’s quarantine zone across affected agriculture and forestry industries.

Researchers are now considering an unusual way of using the relationship against one of the invaders. In 2024, Virginia Tech received nearly $900,000 to study a fungus called Verticillium nonalfalfae that can kill tree-of-heaven. Part of the experiment asks whether lanternflies feeding in groups can pick up the fungus from an infected tree and carry it to another one. The idea is still being tested, but researchers are deliberately asking whether the insect’s attraction to tree-of-heaven can help spread a disease through the invasive tree itself.

More than 230 years after tree-of-heaven was planted in Philadelphia, scientists are testing whether the Chinese insect that eventually followed it can be recruited to help spread the fungus that kills it.

Source: Penn State Extension / USDA APHIS and Agricultural Research Service / U.S. Fish and Wildlife Service / Johnson et al., Journal of Chemical Ecology, 2025 / Virginia Tech.

Photo: John A. Anderson / Shutterstock

09/02/2026

Have you seen this spiny invader along Connecticut forest edges or hiking trails? Or perhaps on your property?

Originally imported as an ornamental, Japanese Angelica Tree is rapidly taking over native habitats across the state. It out-competes local flora, blocks sunlight for young native saplings, and forms dense, single-species thickets. This tree features densely packed spines on both bark and stem. Summer white flowers are followed by dark purple berries.

Do not simply cut this tree down. Cutting will encourage new saplings to sprout and spread. Ask a landscaper to paint stumps with a systemic herbicide designed for woody plants with a Buckthorn Blaster. Protect Connecticut woodlands by sharing this post.

09/01/2026

Giving Our Native Trees Room to Breathe!

Newtown Knotweed Initiative volunteers Christine St. Georges, Ellen Kutner, and Jeff Kutner were out at NFA's Holcombe Hill Nature Preserve yesterday taking targeted action to protect native foliage.

The team tackled invasive Asiatic bittersweet that was wrapping around and choking a beautiful native red maple. Using a precise clip-and-paint method, they cut back the heavy vines and treated the stems to stop regrowth directly at the source—saving the tree canopy and protecting surrounding biodiversity.

The team observed that during their absence from the site this summer, porcelain berry vine moved in to create a veil that covered the tree and surrounding shrubs. In addition, the team stopped as they worked to swat and squish many spotted lantern flies that use porcelain berry as a host.

Every type of invasive vine removed gives our native trees another chance to thrive. Huge thanks to the NFA, Christine, Ellen, and Jeff for their dedicated stewardship!

Have invasive vines taken over trees in your yard? Drop a comment below or send us a message to learn effective, targeted removal strategies!

08/30/2026

Judicious, targeted, responsible use of herbicides can be a successful part of invasive plant management, and in fact, it's essential to wrestle control of some of the worst offenders like Japanese knotweed and tree of heaven.

08/19/2026

Lovely goldenrod (Solidago) is in bloom now. Delivering brilliant color in late summer and early fall, goldenrod is an ecological powerhouse, serving as a crucial, high-sugar nectar and pollen source for native bees, honeybees, butterflies and beneficial insects.

Goldenrod is a larval host plant for over 100 species of butterflies and moths, and its seeds feed songbirds long after the blooms fade.

Contrary to popular belief, goldenrod does not cause hay fever. "People often blame goldenrod for hay fever because it blooms at the exact same time as the real culprit, ragweed. It’s an easy mistake since goldenrod's bright yellow flowers are highly visible in bloom while allergy-causing ragweed flowers are inconspicuous."

We know that plants must be pollinated in order to reproduce. However, the method of pollen distribution varies depending on the plant. Each spring, we get a good idea of one method of pollen transfer...

08/11/2026

Spotted lantern fly-in-a-bottle trick. Any old beverage bottle will do, or in a pinch, a glass jar like this one.

08/11/2026

Invasive vines can be difficult to eradicate using conventional cut-stem herbicide treatment. That's because clinging vines like English ivy, winter creeper and Asian wisteria (and yes, while it is native, poison ivy) develop what are known as "adventitious roots" along their stems. They use these specialized rootlets like tiny suction cups to fuse themselves snugly to rough surfaces like tree bark, stone or masonry, and to absorb added moisture.

If you mistake adventitious roots for the primary root system and attempt to do a cut stem treatment at that juncture, your efforts will fail because adventitious roots don't transport herbicide backward into the underground root system. And if you then leave the main root system untouched, it will respond to your cut immediately by using its energy reserves to send up dozens of new, fast-growing shoots.

You must trace the climbing vines down to where the thick, woody main trunk enters the soil. Then use loppers or a hand pruner to cut the main trunk about 2-6" above the soil line. Then, within 5 minutes of your cut, paint a systemic herbicide containing triclopyr or glyphosate directly onto the freshly cut stump. (Always follow label instructions and wear protective clothing.)

If you are concerned about pollinators landing on the treated surface, you can place a small, inexpensive mesh bag with drawstring over the treated stump and tie it closed, ensuring no insect can land on it, removing it later at your convenience. (Available in bulk at major online retailers.)

Sometimes, the adventitious roots of a vine that touches the ground turn into standard underground roots in a process known as natural layering. If the vine has layered itself, it essentially creates a clone, so in this type of scenario, you have to treat it as two separate plants. Find and treat the original primary root system and then trace the vine to any secondary points where it has taken deep root in the soil and treat those cut stems as well.

How to tell the difference? Adventitious roots can usually be pulled without digging and are fully visible on the climbing stem or when clinging to a surface. Layered roots, on the other hand, are firmly anchored deep underground.

While in theory you can dig out layered roots, it's very hard to remove every single root fragment; a tiny root piece left behind will quickly sprout into an entirely new vine.