Prioritizing your invasive work helps one focus for allotted resources. Look for vines choking native trees. Invasive vines like Oriental Bittersweet are easily tackled in the colder months. This time of year, bittersweet may still have a few red and orange berries and its bright orange roots are a dead giveaway. English Ivy, an evergreen, is very noticeable now. Aerial rootlets along the vine hold fast to bark. Removing at least a one-foot section of this vine is necessary to ensure that rootlets cannot re-attach to the trunk.

A good technique for managing vines is to remove a section with a cut about 12 inches off the ground and as far up as you can safely reach. Resist the urge to pull remaining vines out of the tree for your safety and to prevent tree damage. As long as temperatures are above 45 degrees and the ground is not frozen, you can paint the remaining stump with an herbicide. Painting must be done within minutes or the cut will seal over and prevent absorption of the herbicide. Re-cutting the stump later to apply herbicide is another option. 

If the ground is not frozen, invasive shrubs can be dug out. Shrubs like Japanese Barberry can be cut back now so there is less to do in spring and summer.  Accessing invasive shrubs now is so much easier than in the growing season. Barberry is a very thorny shrub with red elongated berries. Cut stems reveal bright yellow color. Multiflora Rose has downward curved thorns like a cat's claws and may still contain a rose hip or two. Burning Bush is easily identified by winged stems and red berries and this shrub can grow to 15 feet. This time of year, shrubs can be cut to 6 inches above the ground and the stumps immediately painted with herbicide as long as temps are above 45 degrees.

Basal bark painting is another option for invasive shrubs. The herbicide is mixed with an oil carrier to penetrate the bark. The trunk is painted at ground level to 12-24 inches. This method uses less herbicide compared to foliar spraying which uses much more herbicide and is very harmful to beneficial insects.

Invasive trees can be addressed this time of year as well. Invasive Tree of Heaven can be treated with herbicide using basal bark or hack and squirt methods. Once again, temperatures need to be above 45 degrees and the ground unfrozen. If you are unsure about the identification of a tree, you can always tag it with colored tape until definitive identification can be done in spring. Plant identification apps like LeafSnap or Seek by iNaturalist can be helpful. Tagging a treated tree will remind you to circle back in the spring to see if a second treatment is needed. 

Disposal
Never dispose of invasive plants with berries in compost or yard waste. Branches with berries should be bagged and disposed of in the trash. Or, you can also designate an area for a “die-and-dry” pile. Simply construct a sturdy base with your thickest branches, layering more branches on top. Be careful not to allow the root balls to touch the soil. Your invasive pile(s) should be monitored for any regrowth. Placing invasives on a tarp is another option.

Take before-and-after pictures. Doing so will help motivate you and allow you to measure your progress. Even if you don’t have a lot of extra time, tackling one tree or shrub on a weekend day or committing just a few minutes each week will lead to tangible progress. So, grab your coat and get outside to turn the tide against invasive plants in your yard.

The Newtown Conservation Commission is actively working to encourage healthy habitats and increase the diversity of our native wildlife and vegetation. www.newtownconservation.org

Invasive species are harmful in a number of ways. Many invasive plants change soil chemistry making it unsuitable for other plants. Invasive vines smother and strangle important trees and shrubs. Still others are aggressive spreaders that create monocultures in our woodlands and wild places, outcompeting native flora. These are the ways invasives disrupt healthy ecosystems and displace plants essential for providing food and habitat for birds and other wildlife.

Some invasives are extremely harmful to humans. The sap of giant hogweed, for example, contains toxic chemicals that can cause severe burns and risk permanent eye damage if precautions are not taken. Japanese barberry has not only escaped our landscapes to invade woodlands, but it is preferred by white-footed mice seeking shelter in the warmth and moisture of this thorny shrub. White-footed mice are responsible for spreading Lyme disease in North America. The mice infect ticks with the Borrelia burgdorferi bacteria, passed to humans with a bite. According to the CT Agricultural Experiment Station, removing invasive barberry from your property can reduce your risk of tick related illness by as much as 60%.

Eliminating barberry near your home makes good sense. If mice are encouraged to dwell close by, they are likely to find cracks and openings in your home’s exterior, seeking shelter during colder months for warmth, food, and protection from predators.

Sometimes humans seek solutions that actually make things worse. Bait boxes are a perfect example. Bait is meant to be appetizing and to attract. When placed around a building, bait boxes actually bring rodents to your doorstep. And, the poisoned bait does not kill quickly so rodents keep coming back for more. When a victim eventually succumbs to the poison, the bait continues attract new occupants.

Poisons used in bait boxes are called rodenticides and they are horrible poisons that do not kill quickly or humanely.  Animals suffer terribly before succumbing to death. Rodents are not the only victims of these poisons. Many predators succumb to secondary poisoning when they eat a poisoned rodent that is sickened and easy prey. Hawks, owls, foxes, coyotes, bobcats, wolves, raccoons, skunks, opossums, deer, and squirrels have all been victims, either directly or by secondary poisoning. Dogs, cats and even young children are also at risk for rodenticide poisoning.

A Place Called Hope Rehab Center in Killingworth, reports that rodenticides are fast becoming the number one threat to predatory birds of prey (including Bald eagles) due to overuse of these toxic poisons. 80% of raptors they see test positive for second generation anticoagulant rodenticides (SGARS), including birds who were fatally injured from other conflicts, such as vehicle collisions. A bird weakened by the poison is less capable of navigating its environment, increasing the likelihood of a fatal injury. Tufts University conducted a study to determine the extent and impact of rodenticide poisoning on red-tailed hawks. Results showed 97% had been exposed to rodenticides. There is a very low survival rate among victims. Most birds must be euthanized.

Owls, hawks, falcons and eagles all have federal protection and many have been victims of rodenticides. One might ask, how can the use of these poisons be acceptable when they are killing unintended animals, including those with federal protection?

There is simply no justification for the use of rodenticides when safer alternatives exist for controlling rodents. Mice enter homes through small cracks and openings. Sanitation and exclusion are the first line of defense against these intruders. It is important to identify and seal rodent entrance points to keep them out. Additionally, snap traps, CO2 traps, repellents and noise makers are all effective for controlling mice. Fertility control products are an innovative and humane alternative to traditional poisons and effective in reducing rodent populations when used in combination with other non-poisonous methods. For more information, go to www.ctforanimals.org to view webinar videos. 

The Newtown Conservation Commission is actively working to encourage healthy habitats and increase the diversity of our native wildlife and vegetation. www.newtownconservation.org

Often one can justify a negative aspect of something because of some perceived benefit it may offer. When it comes to an invasive plant, we should never make that mistake. Invasives have been determined by scientific evaluation to be harmful in a way that is detrimental to the environment and/or detrimental to human health.

Japanese Barberry is considered by many to have desirable characteristics. After all, it is deer resistant and drought tolerant with not a single pest problem.  But it is these same attributes that makes this shrub an invasive thug. As with other invasives, it has no natural controls as it would in its own country of origin. With nothing to stop it, barberry easily invades forests and woodlands. What’s worse is that barberry creates a serious health risk to humans by harboring and attracting disease-carrying ticks.

Burning Bush is an ornamental shrub that many people choose to plant for one single attribute—fall color. It has no other attraction or benefit and is chosen despite the fact than many attractive and colorful alternatives are readily available. This is another plant that has escaped cultivation and overtaken our woodlands and wild places, displacing native plants that have value to the environment and to us.

Mugwort has been used for a variety of medicinal issues even though there is no scientific evidence of any health benefit. Most people don’t have reason to plant mugwort but are unable to recognize it as an invasive even though widespread along roadsides and fields. This aggressive forb is spread by seed and rhizomatous roots to outcompete all other vegetation. There’s no good in this plant.

It is said that Garlic Mustard makes an excellent pesto. But unless culinary garlic is in short supply, there’s no reason to allow a plant to exist that is capable of changing a soil’s composition, effectively displacing woodland natives. Similarly, Autumn Olive is a shrub that raises a soil’s pH in a way that excludes native species, thereby creating an invasive monoculture. Autumn olive berries might make good jam, but we have so many wonderful berries for jam-making--huckleberry, raspberry elderberry and blackberry to name a few. Could autumn olive jam really be so good it outweighs the bad?

Another plant used for jam-making is Wineberry. This vine with it’s hairy stems is a very aggressive spreader that can cover everything in its path. It’s ability to outcompete native plants is another serious concern.

One of the most evil and damaging vines is Oriental Bittersweet. This vine with its decorative berries should never be used for ornamental purposes because seeds are so easily spread. As with any plant listed on the CT Invasive Plant List, and as directed by CT Gen. Stat. 22a-318d, Oriental bittersweet is illegal to import, sell, purchase, cultivate, transplant, distribute and move. Controlling Oriental bittersweet is important because it is a tree killer. The vine wraps around a tree’s trunk and covers its limbs to weaken the tree until it eventually topples over.

Invasive berries as bird food. It might be argued that birds do eat invasive berries and for that reason have value. But invasive berries lack the proper nutrition. They are high in sugar and have a very low-fat content. Native berries, high in fat, are actually preferred and absolutely essential to birds and other wildlife.

Here in Connecticut, we are so fortunate to have “inherited” so many wonderful and varied native plants, trees and shrubs. But they cannot survive this assault from invasive plants that are literally wiping them out. We are hoping that readers will see these invasive plants for their detrimental side. Clearly, the good does not outweigh the bad.

​The Newtown Conservation Commission is actively working to encourage healthy habitats and increase the diversity of our native wildlife and vegetation. www.newtownconservation.org

In autumn, we marvel at the spectacular colors provided by our native trees and shrubs. Many home landscapes also include non-native ornamental trees and shrubs. Unfortunately, some have escaped cultivation and are wreaking havoc with our environment. Burning bush is one such plant, widely planted for its bright red fall color. Burning bush, Euonymus alatus, also known as winged euonymus, is a deciduous shrub native to Eastern China. It has corky wing-like stems and can grow up to 15 feet tall. Burning bush is considered an exotic invasive plant because it has invaded wooded areas, especially hardwood forests, forming dense thickets to outcompete and displace native species, aided by its extremely dense and complex root system.

Some might argue that the burning bush in their home landscape doesn’t appear to spread.  However, you only have to look into any woodland this time of year to see the truth. Forest understories are completely covered with burning bush, a muted-pink monoculture. This is because burning bush produces hundreds of berries containing viable seeds that are wildly dispersed by birds and other wildlife. These monocultures do not support healthy ecosystems. Diversity of plant species is essential for an ecosystem to function—providing nutrient cycling, pollination, and biomass production. High plant diversity also improves soil temperature and moisture levels which can enhance resistance to environmental challenges like drought.
 
Harm to Birds
Fruit from invasive species has lower nutritional value for birds than native fruit. Research shows that birds prefer native fruits that provide needed fat and energy over invasive fruits, even when natives are few in numbers. This suggests invasive fruits will not sufficiently replace native fruits as food for migrating and wintering birds.  Therefore, we must limit the spread of invasives to ensure our native plant communities can thrive and continue to provide this vital food resource.
 
It's shocking to see that burning bush is still readily available at garden centers because its invasive threat has long been known - shown by scientific evaluation to be invasive and listed on the CT Invasive Plant List for at least a decade. Burning bush is regulated in New York, and prohibited from sale in Massachusetts.
 
UConn has developed a burning bush they say is incapable of producing viable seeds. However, it is not clear if a sufficient amount of time has passed to ensure this shrub will not revert back to fertility. Meanwhile, this shrub continues to be added to our landscapes. Perhaps the Invasive Plant Council (IPC) has reservations because this summer, they moved to phase out and ban burning bush in Connecticut but did not commit to making allowance for sterile cultivars. As of October 2028, burning bush is prohibited from importation, movement, sale, purchase, transplanting, cultivation and distribution.
 
Alternatives
Why choose a non-native shrub whose only attribute is short-season attraction—no attractive flowers, no winter interest, no ecosystem value or benefit to wildlife. When replacing or adding shrubs to your landscape for fall color and so much more, consider natives such as Highbush Blueberry, Chokeberry, Viburnums, Fragrant Sumac, Spicebush, Northern Bayberry and Witch-hazel.
 
Control
If you have burning bush, there are options for removing it. Young plants can be pulled or dug. For larger plants in low-density invasions, a root-wrenching tool can be useful. Cutting large plants at ground level will cause burning bush to resprout shoots from the base, making it more difficult to treat later on. Foliar herbicide treatments are an option from mid-May through October. Basal bark and stump treatment (on fresh cut) can be done all year as weather permits. Always a good idea to consult a licensed pesticide applicator. More information can be found at the Penn State Extension website.

The Newtown Conservation Commission is actively working to encourage healthy habitats and increase the diversity of our native wildlife and vegetation. www.newtownconservation.org

Spotted lanternfly (SLF for short) is a destructive sap-feeding planthopper. SLF is a relatively new plant pest to the United States. While just two small populations were verified in Fairfield County in 2020, it is now found across CT and widespread in Fairfield and New Haven counties.
​
A pretty distinctive insect, adults are about one inch long and a half inch wide. Their forewings are tan with black spots. Hindwings, noticeable when wings are spread, are colorful red and black patches separated by a white patch. Adults are active from July to November and will crawl, jump, or fly short distances. ​

Invasive Tree of Heaven (Ailanthus altissima) is the preferred food source (host plant) for the spotted lanternfly. This rapidly growing deciduous tree has become a widespread invasive species across North America. Also known as stinking sumac or Chinese sumac, it was introduced to the U.S. as a horticultural specimen and shade tree. Rapid growth and abundant seeds allow it to spread aggressively to create dense thickets that displace native vegetation. It also secretes a chemical into the soil that is toxic to surrounding plants.

While spotted lanternfly is attracted to tree of heaven, it also feeds on economically important plants including grapevines, ornamentals, and native trees such maple, black walnut, birch and willow. Feeding damage significantly stresses plants, impacting health with potential for causing death. For additional information, go to the Connecticut Agricultural Experiment Station and search: spotted lanternfly.

Protect your property and trees. The CT Agricultural Experiment Station says the best thing a homeowner can do is rid your property of Tree of Heaven, so not to attract spotted lanternfly. Local arborist, Mike Switser of North Country LLC, is fully licensed with expertise in proper management.

How to Identify Tree of Heaven
It is important to correctly identify the tree of heaven. On first glance, it appears similar to some native trees and shrubs that also have leaves arranged in pairs along a plant’s stem (staghorn sumac, hickory and black walnut). TOH is distinguished by a notch at the base of each leaf, fuzzy, reddish-brown twigs, and clusters of light green seed pods. If all else fails, there is the unmistakably strong, offensive smell to its flowers, leaves and stems when crushed, resembling burnt peanut butter.

A multiple threat. If displacing native vegetation, threatening natural ecosystems, and attracting a destructive pest isn’t harmful enough, tree of heaven with its aggressive root system can also damage pavement, sewers and wells, and building foundations. 

Controlling Tree of Heaven
According to the Penn State Extension, cutting alone will not reduce tree of heaven’s ability to spread, in fact, it could make it worse. Pulling TOH out can also activate the root system, causing it to send up more shoots to create new trees. The best method is to target the roots with a systemic herbicide applied mid-to-late summer until onset of fall color when the tree is moving carbohydrates to the roots. Herbicides can be applied to foliage, bark, or cuts on the stem, also known as hack and squirt. However, cut stump herbicide applications do not prevent root suckering and should not be utilized. Herbicide applications made outside this late growing season window will only injure above ground growth. As always, employing the help of a professional licensed pesticide applicator is recommended. For more information, watch Penn State Extension's guide for controlling Tree of Heaven.

The Newtown Conservation Commission is actively working to encourage healthy habitats and increase the diversity of our native wildlife and vegetation. www.newtownconservation.org

We asked Hannah Hudson, founder of the Worldwide Japanese Knotweed Support Group to answer
commonly asked questions for battling Japanese Knotweed. Hannah started the Support Group in 2015, after
discovering that accurate data and up-to-date guidance was lacking in the U.S. compared with the United
Kingdom.

Knotweed is atypical of other invasive weeds, requiring a long-term, science-based control method
as outlined in the Springer study, Jones, D., et al. "Optimizing Physiochemical Control of Invasive Japanese Knotweed." Biological Invasions, vol. 20, no. 8, 2018, pp. 2091–2105. https://doi.org/10.1007/s10530-018-1684-5

​Will regular mowing control knotweed?
Regular mowing worsens knotweed infestations by leaving the deep, extensive root systems intact  and stimulating further underground spread. Effective control requires targeted herbicide treatment during the appropriate season. Mowing alone can also unintentionally spread the plant through viable plant fragments.

Can you tarp knotweed?
Tarping is largely ineffective against knotweed because it mimics a weak barrier compared to the plant’s native volcanic environment, where it evolved to survive under lava. Knotweed will simply grow underground in search of sunlight, often emerging beyond the tarp’s edges or even through thin material.

What is the most effective way of treating knotweed?
The 2018 Springer Report recommends 41% glyphosate, diluted to a 2-4% concentration. If the herbicide is
too strong, it will burn the leaves before it can be drawn down into the root system.

When is the best time to treat knotweed?
Herbicide treatment in spring or early summer fails because knotweed is pushing energy outward, preventing
the herbicide from reaching the roots. The most effective time for treatment is during the Flower to Fall Treatment window. This is from the first flowers to 2 weeks before the first frost when the plant draws  nutrients inward, allowing glyphosate to reach and weaken the root system from within.

If I have a very tall infestation, can I cut it in early June for easier access?
Cutting knotweed in June may ease access but can disrupt its natural cycle, causing it to push energy outward
and reducing the effectiveness of fall herbicide treatment. You also have the issue of removing the plant material. Many prefer to wait and spray during the fall window without cutting, preserving the plant’s inward flow to maximize root absorption and minimize spread risk from cut material.

What is the best way to dispose of cut stalks?
Freshly cut knotweed stalks must be dried above ground or double-bagged and bagged as trash, as even small fragments can trigger new infestations; composting or improper disposal in landfill is unsafe. Herbicide-treated stalks ONLY can be safely cut in winter when brittle, but cuts should stay above the crown to avoid disturbing live roots capable of regrowth. Never pull them out of the ground.

I have concerns about using glyphosate.
While concerns about glyphosate are common, it is considered the least harmful herbicide option for treating
knotweed and is even granted exceptions in some areas where it's otherwise banned due to its effectiveness
and minimal environmental persistence. For more information, go to the Northeast Knotweed group on Facebook or the Newtown Knotweed Initiative.

The Invasive Insider is published quarterly in cooperation with The Newtown Bee by the Newtown Conservation Commission.

Invasive plants that produce fruits must be dealt with during the summer months before their fruits ripen. Otherwise, birds and other animals will spread the seeded berries into new areas, sometimes over great distances. The territory of an overwintering bird like our Northern Cardinal can be up to ten acres. Of course, birds that migrate in fall will spread seeds much farther. The issue with invasive plants is that they are displacing native vegetation essential for many wildlife species. Fruit-bearing invasives of concern include Japanese Barberry, Burning Bush, Autumn Olive, Mile-a-Minute vine, Wineberry, Porcelainberry and Oriental Bittersweet vine.

Invasive plants are very aggressive. Leafing out earlier than native species combined with prolific fruit/seed production, gives them a huge advantage for growth and reproduction. Many invasives create monocultures to crowd out other vegetation (Barberry, Burning Bush). Others cover and smother vegetation (Mile-a-Minute, Porcelainberry (pictured). And, many invasive plants also reproduce vegetatively as stems arch to the ground to produce new plants (Wineberry).

Oriental Bittersweet (Celastrus orbiculatus) is a tree killer. This invasive vine is extremely destructive. It climbs with twining stems to strangle the limbs of shrubs and trees, growing to great heights in search of more light. Vines can get huge, several inches in diameter and their weight can uproot and topple trees. Primarily spread when seeded berries are dispersed by birds, bittersweet can also reproduce by root suckering. Two native vines that climb but do not harm trees are poison ivy, “leaves of three, let it be” and Virginia creeper, “leaves of five, let it thrive.” Both these vines are immensely beneficial to wildlife. However, poison ivy is considered a “problem native” due to the allergic reaction it causes in humans.

Bittersweet vine is common an easily identifiable. Young plants send out “tentacles” that wrap around any tree, shrub or object they encounter. When pulled or dug, bittersweet reveals its distinctive bright orange roots. In late summer, fruits unlike any other, have a yellow outer shell that opens to a fleshy red seed covering.

Controlling Oriental Bittersweet – as always, early detection is important. Small sapling plants can be easily removed by pulling or digging when the ground is moist, making sure to remove the entire root. Cutting alone will not provide effective control as it stimulates resprouting, however cutting will reduce its destructive effects to trees and shrubs for the short term. Vines above the cut are best left in place since pulling will damage tree branches. Dead vines will eventually deteriorate. The CT Invasive Plant Working Group recommends cutting and painting with an herbicide during the growingseason to control Oriental Bittersweet. Penn State Extension is another excellent source for information on controlling bittersweet and other invasive plants.

Disposal of Invasive Plants – Invasives without mature berries/seeds can be placed in a brush pile. If mature berries are present, plants should be placed in a designated area where they can be monitored for reseeding or bagged for incineration. Invasives with berries or seeds should never be placed in a compost pile or in the brush area at the Town Transfer Station.

The Invasive Insider is published quarterly in cooperation with The Newtown Bee by the Newtown Conservation Commission.

​Do you know what plants are growing on your property? Chances are there are some non-native invasive
plants on borders and wooded areas. Invasive plants are aggressive exotic plants that were introduced either
intentionally for ornamental purposes, or accidentally by hitchhiking on other plants or products. Invasives
thrive in a variety of growing conditions with no natural enemies to control their rapid spread as would occur
in their own place of origin.

The environmental costs of invasives are high – they displace native vegetation and reduce biological
diversity, altering the way plants, animals, soil, and water interact within native ecosystems. And they pose a threat to endangered plant and animal species.

Invasive plants can also be a threat to human health. Japanese barberry (Berberis thunbergii) is a spiny shrub with a twiggy form. Pale yellow flower clusters bloom April-May. Bright red berries develop in late summer and persist into winter. Common in home and commercial landscapes, barberry has escaped cultivation and now grows wildly throughout Connecticut’s woodlands, creating dense thickets that prevent native trees and wild flowers from regenerating. Barberry also poses a risk to human health. A study conducted by the CT Agricultural Experiment Station - Williams, et al 2017, revealed a frightening discovery. Barberry-infested forests had a significantly higher abundance of ticks, with the causal agent responsible for Lyme disease, than in forests free of barberry. The study concluded that managing barberry can significantly reduce the abundance of ticks and the risk of tick-related illness.

The most important thing one can do to control invasives is not to plant them. While Japanese barberry
and other invasives are still sold, there are many excellent native alternatives. Second, it is important to take
action as soon as an invasive is identified in your yard. Once established, many invasives can be difficult to
remove.

The approach used for controlling invasive plants depends on the species and how large the infestation. Early detection is important. Invasive plants like barberry leaf out earlier than our native species. Barberry’s teardrop-shaped leaves are easy to spot in early spring in wooded areas and along edges. Small plants can be easily managed by pulling or digging when the ground is moist, making sure to remove the entire root. Larger plants when cut reveal its bright yellow inner stems and roots. Cut stems can be chemically treated. We refer to the Invasive Plant Management Calendar published by the CT Invasive Plant Working Group (CIPWG) for information on chemical control of barberry. This calendar, along with more information on invasives, is posted on the Newtown Conservation Commission website.

Disposal of invasive plants is an important consideration and depends on the invasive and timing of removal. Barberry, without mature berries/seeds, can be placed in a brush pile. If mature berries are present, plants should be placed in an area where they can be monitored for reseeding or bagged for incineration. Invasives with berries or seeds should never be placed in a compost or brush pile, including the Town Transfer Station.