Found downstate – watch for


An invasive wood boring insect introduced from Asia that feeds on a variety of hardwoods including maple, birch, elm, ash poplar and willow plus others. The loss of many landscape and urban forest trees, along with the ecological services that these trees provide, would be a devastating loss to New York State’s forestry sector and hardwood timber industry. Additionally, New York State’s maple industry, which produced 800,000 gallons of maple syrup in 2019, is at risk from ALB as maples are the preferred host. 

How to identify

Beetles are 3/4 to 1.5 inch long, have long black & white antennae & shiny white spots on their wings. They have been found in NYC, LI, Mass. & Ohio. Signs of infestation are 3/8 to 1/2 in.  round 1 in. deep exit holes from adults emerging from trees in late July and round ½ depression (egg-laying sites) in the outer bark.  Sawdust-like material will collect on branches & around the base of the tree. Females often chew depressions in the bark where they deposit one to two eggs at a time. After the hatch the larvae bore into the tree and begin feeding on the living tissue underneath the bark which disrupts the nutrient and water flow within the treeThe invasive species has a native lookalike, the white spotted pine sawyer, but there are a few key differences. The Asian Longhorn Beetle is shinier than the native white spotted pine sawyer.  While both insects are dark in color with white spots, the white spotted pine sawyer has a distinctive white spot between the tops of its wing covers. 

Left: Native Pine Sawyer  Right: Invasive Asian Longhorn  


NYS DEC has identified locations and so far, successfully guarantied most infestations.   Do not move infected firewood. Take pictures of the infestation signs as described above (include something for scale such as a coin or ruler).  Note the location (intersecting roads, landmarks or GPS coordinates); then Email DEC Forest Health at  or Call the ALB tip line at 1-866-702-9938.  The NYS Dept. of Ag & Markets has taken the lead on surveying for infested trees.  See

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Left: Round depressions where eggs are laid  Right: Round exit holes are up to size of a dime 

Adhere to NYS firewood regulations, currently firewood cannot be moved more than 50 miles.

Threatening, Found downstate, central & western NYS


Affects and kills both native and ornamental beech tree species. Beech trees are a significant % of our watershed.   It can kill mature beech trees in 6-10 years and some cases have shown saplings killed in one year.  First discovered in 2012 in Ohio, the disease has now been located as far east as Massachusetts. Has been found in western and downstate NY counties.  

What is Beach Leaf Disease

It is associated with a nematode. Nematode feeding can begin at bud break causing dark banding between the veins of tender foliage. As the season progresses and damage worsens the leaves become leathery in texture and dark banding can turn yellow and kill affected branch tips.

How to identify

Symptoms are seen in the leaves including striping, curling and/or leathery texture.  These symptoms may be visible from leaf out in May until the leave fall in Fall.  In early infestations, only a few leaves may be affected.  A single tree can contain both heavily infected and unaffected branches.  The backlighting seen when looking up into the forest canopy can help you spot the leaf striping associated with BLD.

Left: Curling Right: Striping


This disease has only been discovered in recent years and much about it including the full cause and how it spreads is still unknown. Currently there is no known way to control or manage this disease.   DEC is collecting information on symptomatic beech disease across New York State in the hopes of learning more about the disease. Take photos of symptoms, as well as the tree’s leaves, bark, and the entire tree if possible and email to DEC at or call 1-866-640-0652.   

Follow NYS firewood regulations to help prevent the spread – Do Not move firewood more than possible and not more than 50 miles (NYS law).Note- there are other beech diseases, see for pictures and descriptions for more info.


This woody shrub forms dense thickets crowding out native plants inhibiting forest regeneration. Spreads long distances into forests by birds dispersing fruit & seeds.  It grows well in full /partial sun and was planted as an ornamental.  Once established, bush honeysuckles form dense thickets There are four similar species that are invasive and native to Asia and Western Europe (Amur, Morrows’s, Tartarian and Belle are referred to as Bush Honeysuckles).

How to Identify

This shrub grows 6-15 ft tall and wide 20+ ft. Leaves are oval, opposite with smooth edges. Grey Stems are hollow. It flowers in May / June with pink, white or yellow blooms followed by clusters of red, pink or orange berries in late summer. They are the first woody shrub to produce leaves in the spring. 



If you like honeysuckles, remove the above invasives and replace with  natives- (Canadian, Trumpet, Limber and Northern variety). Larger plants require foliar herbicide treatment- Glyphosate or Triclopyrs throughout the season. Treat cut stems with same.   Smaller plants can be dug but leave dug plants on site following removal and do not let roots contact soil.  Mowing with a brush cutter can be used as a suppression technique.  Burn removed plants.


Ash comprises up to 8 % of NY communities. Ash seeds are a food source for birds and mammals. The tree is valuable for flooring, furniture, lumber and pallet manufacture. First found in NY in 2009, it is found in almost all counties. Recently it has been found along the Schroon River in Chestertown. It has killed more than 50 million trees across the country.

ash trees before (left) and after (right)

What is EAB / How to Identify

A small beetle that attacks only ash species. Its larvae enter the tree thru crevices in the bark and then feed on the inner tissues of the tree disrupting the tree’s ability to transport nutrients and water. Four life stages; adult, egg, larva and pupa.  The adult beetle has shiny emerald bright green wing covers & a coppery red or purple abdomen.  Adults- 3/8 to 5/8-inch-long & 1/8 inch wide, emerge from May thru Sept. most commonly in June & July.  Females lay eggs 2 weeks after emergence, hatching in 1-2 weeks. Larvae 1 to 1 ¼ “long, bore into the bark leaving long serpentine tracks underneath. Feeding disrupts the ability to transport water & nutrients resulting in dieback and bark splintering.   

Signs of infestation

dieback, thinning, usually starting at canopy top, epicormic shoots from the tree base, woodpecker activity, bark splitting.   Heavily infested trees die within 2-3 years of when symptoms are observed.   On the trunk and branches, look for small (1/8 in. diameter) D-shaped holes that are left by emerging beetles.  When the bark splits or falls off, S-shaped larval galleries may be visible.  Adults feed on the ash leaves in the canopy but cause little defoliation.   Adult EAB’s typically fly less than ½ mile from their emergent tree thus it spreads by firewood movement.  

 “D” shaped exit hole 

serpentine galleries under bark

EAB Larvae


Emerald Ash Borer Look a likes

The six spotted tiger beetle (below) is often mistaken for EAB. Also, the bronze birch borer that also has D shaped holes.

Left: six spotted tiger beetle Right: Bronze birch borer (native)

How to identify ash trees

Ash trees can grow 60 to 100 ft. The leaves are pinnately compounded with 5 to 11 leaflets. Clusters of small white flowers develop on the twigs during the spring.  The fruits (winged) are light green in color changing to brownish.  Branches, leaves and buds are directly opposite from one another rather than staggered. Older tree bark has a diamond-shaped ridges. Smaller ash tree bark is often smoother. 

Ash leaf

Ash leaf and bark

Ash fruit

What to do / Help / Report

Do not move firewood. NYS law prohibits movement of firewood more than 50 miles, so buy your firewood locally.   EAB is spreading rapidly thru human transport of infested wood and ash nursery stock.  

There are a variety of treatment options that can serve as a control measure for the EAB, but no cure. While DEC is still collecting EAB location information, they are not actively managing infestations at this writing.  It is cooperating in efforts to identify potentially resistant trees, estimated at 1 % of the population. Biological efforts are underway to contain and eradicate but the success of these efforts will not be known for several years. Management and controls are constantly evolving.  Systemic Insecticides are available but are only considered viable in urban areas; Emamectin Benzoate is the most effective, also Imidacloprid (available to landowners -Bayer Advance Tree & Shrub, but only as a soil drench) and Dinotefuran.  A certified arborist is required for most treatments.    

In urban areas trees should be removed once an infestation is found to reduce further spread More info;     & the DEC webpage you confirm a tree is infested with EAB it may not have to be taken down. With treatment, trees can be saved before 30% is affected.   DEC can confirm if the signs of tree damage are from EAB and provide tree information removal.  If you suspect you have found EAB, take photos of the insect or signs of damage and email them along with location information to  &/or call 1 866-640 0652.


A noxious biennial herb averaging 3 + feet that emerges in early spring. Native to Europe, Asia & NW Africa, it invades moist forests, wooded streambanks, roadsides and trail edges where it disrupts normal plant – fungi relationships that results in elimination of native species. Its roots exude compounds that alter soil chemistry to favor its survival at the expense of other species. Each plant can produce thousands of seeds. Difficult to control once established.   

How to identify

It begins as an inconspicuous first year plant (rosette) that look similar to wild violets having triangular somewhat heart shaped leaves that have coarsely toothed margins and wrinkled leaf surfaces. 2nd year -it can send up multiple stems with a tall flower spike with four petal white flowers developing into slender pods bursting with tiny round seeds. 2nd year leaves have sharp teeth.  Leaves & single stems produce distinctive garlic odor when crushed. Seeds may be viable for 10 years.

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Garlic mustard is not browsed by herbivores and has no effective insect pests or diseases.  Small infestations can be hand pulled before seed production by late June.  All root material must be removed and bagged and solarize (left in sun for at least two weeks before disposal).  Pulling up large swaths of garlic mustard is futile.    Large infestations- use a foliar herbicide spray such as Glyphosate or Triclopyr.   Do not compost!     Monitor site in fall and pull any new plants.  It may be edible, unfortunately eating it has not worked well as a control strategy. 

There have been studies that suggest that not managing it / i.e., leaving it alone for 10 years, it becomes scarce as a species and the remaining plants greatly stunted.  Where it has been “managed”, the plants are considerably larger and cover a higher percentage of a site.

Best strategy, don’t let it get established.

Now found at multiple Lake George locations


The EasternHemlock is a vital component of our forest system.  NY has more hemlocks than any other state in the nation and are concentrated (10 % of our forest) in the SE Adirondacks. It is the fourth most common tree in NY forests. Growing on steep terrain, they provide erosion protection along stream banks, food and shelter for deer and wildlife.  Major changes in eco-system structure, function and hydrologic processes are expected with the loss of hemlocks. The understory of a hemlock forest is characterized as dark, damp and cool and is an ideal habitat for organisms such as amphibian species, plants and maintain a suitable environment for cold-water species such as brook trout. Vulnerable animal populations are expected to diminish as a result of hemlock habitat loss.  Well suited for growing on steep slopes where not many other species can grow, hemlocks stabilize shallow soils and provide erosion control. HWA could kill most of the region’s hemlock trees within the next decade if not controlled.

Effect of HWA- Dead Hemlocks in mixed forest

What is HWA? 

This introduced tiny aphid-like insect from Asia, first observed in the eastern US and was first found in Lake George in 2017. It feeds on Eastern Hemlock of all ages causing extensive decline.  It does not affect pine, spruce, fir or other conifers. Tree injury occurs as a result of the insect sucking sap while feeding causing the needles on infested branches to dry and drop. Buds are killed so little new growth is produced on infested branches.   Mortality typically occurs within 4 to 10 years of infestation.  Trees weakened by HWA often succumb to diseases and wood boring insects.  

During March and April, adults of the overwintering generation each lay up to 300 eggs within a “woolly” covering. Crawlers hatch from April thru May settling on the twigs near the needle base where they insert their piercing and sucking mouthparts feeding through-out their development.  The spring generation matures by the middle of June with crawlers hatching in early July and settle on new growth becoming dormant till Mid October when feeding resumes and the characteristic woolly covering begins to develop. Nymphs feed during the winter and mature by spring.   It spends most of its life attached to the twig. Eggs and crawlers – the only stage that are unattached – are present from March through July and are readily spread by wind, birds and other mammals including people. HWA is only mobile from mid- April thru mid-June.

How to identify HWA

The most obvious sign of HWA is the covering of white wool-like wax filaments (egg sacs) produced as the insect matures which cling to the underside of branches.  These woolly masses generally range from 1/16” to 1/8” in diameter and can be seen where the needle attaches to the twig.  They are most visible from late fall to early summer on the undersides of the outermost branch tips of hemlocks.  The insects will have little wool in November and by March the “wool” will be well developed.   As they feed, their woolly covering expands resembling the tip of a cotton swab. This “wool” covers the insect in all but its earliest life stages. Trees that have been impacted for years will also display; 1. off color needles, often with a grayish-cast, 2. thinning crowns, 3.  premature needle loss.   In late May and early June, look for lighter green new needle growth (see Pic below).  If branches do not have this new growth, examine closer for possible HWA.                                                                                                                                                See New York State Hemlock Initiative– sacks on underside of branches (2)

Egg sacks on underside of branches

Dormant HWA, very small and wool starting to develop

New lighter green growth (late May thru early June) indicates healthy tree

HWA Life cycle

Note; HWA Imposters

You may see these look-a-likes on hemlock trees including Spittle bug (wet mass of bubbles, not harmful), Spider egg sacs (larger balls of webbing connecting needles and twigs – not harmful), Elongate Hemlock Scale- (white or brown ovals on underside of needles (invasive insect- report to DEC).        

Left: Spittlebug on pine. Right:Elongate Hemlock Scale (invasive)

How to identify hemlock trees   

Hemlocks have flat evergreen needles ranging from 1/3 to 2/3 inch long with two white parallel lines on the undersides of needles.  Cones are about ½ inch long and green when immature. Bark is gray brown with wide ridges and furrows. 

Hemlock needles, note white lines on underside

Hemlock needles/cones
Balsam fir branches and cones

HWA Management It is important to detect HWA early to maximize management options. In addition to winter when the white sacs are most visible, inspections twice a year (beginning and end of daylight savings time) of the underside of branches is the best way to tell if a hemlock is infested.   

Hemlocks growing in landscapes can be managed through an integrated approach including monitoring, practices to enhance tree vigor and pesticides.  Control of forest trees are limited except for early detection and subsequent management. NYS DEC and APIPP is aggressively addressing this threat. DEC crews are using bark applications of the chemicals imidacloprid and dinotefuran to treat infested hemlock. Direct injections are used for ecologically sensitive areas. 

Clipping heavily infested twigs from branches will reduce populations. Burn any clippings.  When a tree becomes heavily infested, the tree should be removed in the fall or winter.  

Biological controls studies are underway with beetles which feed on the adelgid are showing some promise. Two species of silver flies that feed on the eggs and are natural enemies of adelgid species are being studied by DEC and partners.

Chemical control is most effective option for managing infested hemlocks.  Infested trees usually decline rapidly in the absence of chemical control. Periodic treatments are necessary.    There are two systemic pesticides that are used to treat HWA in NY- Imidacloprid (available to landowners only as a soil drench, a certified applicator is required for other methods) and Dinotefuran.     Imidacloprid is available at garden stores and the most common name is Bayer Advance Tree & Shrub.  Treatments with one of the several formulations of Imidacloprid (active ingredient) registered in NY have been found to be effective up to 7 years with just one treatment. Imidacloprid can be applied by soil drench, soil injection, time-release soil tablets, trunk injection, or basal bark spray.  

Always read the label and follow its directions carefully for any pesticide application. For the soil drench, pull the leaves and other organic material 2 feet away from the base of the tree, then pour the correct amount onto the soil. Homeowners should be aware that a soil drench can move through porous soil into waterways; it’s best not to use a soil drench within 75 feet of any body of water. Soil drench and soil injection work best when the soil is moistened after a rainstorm, not when it is dry. Hemlocks prefer wet soils and are usually found around waterbodies, so this may not be the best option.

What to do /Help / Report

The 2017 find in Lake George was treated with an insecticide and eliminated by DEC, but it was again found in multiple location in 2020.  DEC treated 2700 trees in this outbreak.  More info-

Contact DEC- Email report and photos to DEC Forest Health at  Or call the Forest Health Information Line at 1 866-640-0652.  

Contact- APIPP (Adirondack Park Invasive Plant Program) 518 576 2082 or HTTP://  PO Box 65, Keene Valley NY 12943.


Note; there is also a Balsam Woolly Adelgid but while it has been reported in the northeast, there is not much literature on it as a threat.   The trees can be differentiated by the needles and cones which are upright while the cones of the hemlock are smaller and pendant. See pictures above.

Widespread in our watershed now


Aggressive non-native, spreads rapidly, forms dense thickets and crowds out native understory plants.  Barberry is unpalatable for local wildlife and serves as a deer tick habitat and is implicated in the spread of Lyme Disease.

What is Japanese Barberry?

A dense deciduous spiny shrub, 2-8 ft tall with small oval to spoon shaped green, yellow or purple leaves with smooth margins that turn red in fall. It has tiny pale yellow dangling flowers that hang in clusters of 2-4 nodes that bloom in April and May.  Grows well in bright sun or shade. It spreads by seed, clonal shoots below ground and by the tips of its branches where they touch the ground. Spreads long distances into forests by birds. 

How to identify

Arching branches are grey with sharp thorns.  Yellow inner wood of roots & stems. Berries-bright red oval shaped. Leaves out early and retains its leaves late into fall.  Small oval to spoon shaped leaves with smooth margins arranged in clusters around the stem.   

Control / What to do / Help

Fairly easy to control. Small plants -dig and burn before seed dispersal but entire root system must be removed as they will re-sprout.  It has shallow roots which are easy to pull but remove the root crown as well.  Wear gloves. Larger plants require foliar herbicide treatment such as Glyphosate or Triclopyr once the barberry is fully leafed out.  Be sure to read instructions.

A “non-herbicide” solution is to use a foliar 1 gal. spray mixture: 75 % of 20 to 30 % concentrated vinegar and 25 % water, 1/2 cup salt and 1/4 cup dishwasher soap is effective.  Cover all stems and leaves.  Be careful- vinegar is acidic- wear appropriate eye protection and safety clothing.  Make sure all leaves are covered but avoid overspray. High % vinegar typically is not found in grocery stores but can be purchased on line. One commercial product is Green Gobbler.  Avoid spraying during windy or damp or rainy conditions.

In our watershed


Introduced into the US from Asia as an ornamental, once sold in seed catalogs and was considered a problematic pest by the 1930’s. It is one of the most common invasive plants in the Adirondacks and spreading rapidly.  In the last 10 to 20 years, JK has entrenched itself along stream banks, roadsides and woodlands. It grows extremely fast, crowding out native vegetation and altering the landscape. Native plants are rapidly out-competed.  Without prompt and vigorous action, knotweed damages the scenic and recreational quality of our Adirondacks.

What is JK

Upright herbaceous perennial that can grow from 3 to 15 ft tall, have hollow bamboo-like stems creating monocultural stands.  It tolerates shade, and drought and is found along roads, right of ways, old farmsteads, streams and rivers.  Thriving in disturbed areas, it spreads by its extensive root system and seed dispersal.  Its shallow root system is ineffective at preventing streambank erosion or stabilizing soils.  New colonies are spread by seed and can sprout from plant fragments as small as ½ inch.  It is sometimes spread by contractors dumping contaminated fill.

How to identify

Stands are very easy to identify. Stalks are persistent through winter. Leaves grow in an alternating pattern on the stem and average 6 inches in length and 3 – 4 inches width. Leaves are heart shaped or broadly ovate (round at the base and triangular or heart shaped, pointed at the tip) to somewhat triangular.  Plants sprout early in spring quickly dwarfing surrounding plants.  The horizontal roots can reach lengths of 65 feet or more.  Colonies are dense and thrive in shade and sun.  In August, clusters of small greenish white flowers arranged in spikes near the end of the stem bloom in Aug. to Sept. turning to buckwheat-like seeds by early October.  Upon cold weather growth ceases, leaves and seeds are shed and the stems take on an auburn or rusty hue.

Left: flowers Right: Spring – early shoots

What to do / Help / ControlFirst, a disposal plan for all knotweed material is essential to prevent future colonies. Re-vegetation after treatment is necessary as bare ground allows for re-invasion of knotweed.  Regardless of methods, eradicating knotweed is typically a 3-5 year process.  Be prepared to make follow up visits. There is no insect, pest or disease that can keep it in check. Do not mow or cut with weed trimmers as the pieces of the plant will re-spout spreading rather than controlling the plant.  Do not transport knotweed fragments / cuttings. Do not take to a landfill.  Do not let sit on ground where it can resprout.  Burning is an acceptable disposal method.  

Single young plants may be pulled by hand depending on soil condition and amount of root development.  100 % of the root /rhizomes must be removed for effective management.  Not recommended for established patches.

Herbicide controls – Stem injection in May – June with glyphosate, available in garden stores as Round Up, is currently the most effective solution. Inject stems between nodes when plants are 3 ft tall with developed leaves after stems are cut to 2 inches above the ground. (See APIPP below.)   As of the plants energy is stored in the extensive rhizome system, this method is effective and results in 95 % reduction.  Follow up with foliar spray applications with glyphosate and triclopyr to the foliage and freshly cut stems can be effective but most will require multiple applications.    Do not use foliar prays when the plant is flowering to protect pollinators during treatment.  Do not use foliar sprays along stream beds, only stem injection. 

 Recent attempts to introduce biological controls, i.e., beetles that attack the plant in their native lands have been totally ineffective. Also, attempts to cut down and then cover it with tarps like-wise have been in effective.

 Contact APIPP * who has helped landowners with loaning stem injection equipment.   518 – 576 – 2082    

This is a nasty plant and a world-wide problem. Best control is not to let it get established.     Our Adirondack Kudzu!

  • Adirondack Park Invasive Plant Program   / Nature Conservancy located in Keene Valley, and a ESSLA partner.

Threatening, found downstate & Plattsburg


Native to Asia, this highly invasive herbaceous annual vine that can grow 6 ‘” a day and reach heights of 18 ft or more. It colonizes fields, streamside wetlands, upland forests and roadsides. It quickly grows over and out-competes native plant species.  It is a prolific seeder and seeds germinate in early spring.

How to identify

Its stems are covered with barbs which are also present on the undersides of its leaf blades. Seeds can remain viable for up to 6 years. Tolerates some shade but does best in full sunlight.  Vines have alternate light green triangular leaves. The vines are light green and become reddish as they mature.  Stems and undersides of leaves have recurved barbs which helps it climb. A unique feature are rounds flat leaves that circle the stems.  Ripe fruits produced mid-summer thru fall are blue. The vines are killed by Fall frost and the seeds overwinter in the soil.

“Kudzu of the north” 


Hand-pulling of vines can be effective; ideally before the barbs harden, afterwards thicker gloves are needed. Pull and bale vines and roots as early in the season as possible. Later in the season, vines must be pulled with caution as the fruit could be knocked off or spread more easily. Collected plants should be burned. Dry piles left on site should be monitored and managed a few times each year to ensure any germinating seedlings are destroyed.  Mile-a-minute weed can be controlled with commonly used herbicides in moderate doses. The challenge with herbicides is mile-a-minute’s ability to grow over the top of desirable vegetation, and spraying the foliage of the weed can be challenging. Pre-emergent (herbicides -that prevent seed germination) can be used.   When getting ride of this weed, remember an important task is to prevent the seeds from spreading.

Threatening our water shed.  Watch for! Found in Schenectady County 


A fungus that blocks water and nutrients killing all oak species but red oaks (pointed leaf tips) often die within weeks to 6 months while white oaks can take years to die. First discovered in NY in 2008, the disease can spread long distances by airborne spores in open wounds caused by wind damagepruning, or other mechanical damage. It also spreads by above ground beetles and bugs attracted to the sap and thru underground roots of nearby oaks.  Now found in Schenectady county.  DEC will conduct oak wilt management based on the site.   Oaks provide a wide range of benefits including food for wildlife such as deer, turkey, squirrels. 

How to Identify

The most common sign is brown coloration developing on leaves starting at the outer edge. Branch dieback starts at the top of trees canopy and leaves suddenly wilt in the spring and summer and may fall while there is still some green on them. Infected red oak trees will begin to lose over half of their leaves in July and August.   White oaks develop the disease much more slowly and only one or two branches may be symptomatic per year.  The fungus overwinters on dead tissue from diseased trees.  A less common symptom in both species is the formation of bark cracks which hide sweet-smelling spore mats.



Do not move infected firewood or any firewood more than 50 miles (NYS law). There is no way to save an infected oak tree; the only way to deal with oak wilt is prevention.    Since the fungus enters the tree through wounds, avoid injuring oaks between April and August. That means no pruning during those months, and careful maneuvering around oak trees with your lawnmower and other power tools.   If an oak gets cut down or injured during that time period, cover the stump or spot with a special tree wound dressing or latex paint to seal it off. And do it immediately, as it takes sap beetles as little as half an hour to find the new spot and start feeding on it.   Oak wilt spores can be spread by beetles when they land on open tree wounds so sealing wounds and stumps with paint can help prevent infection.   Action- E mail NYS DEC.  with location and pics to;  or call the Forest Health Info Line at 1-866-640-0652.  NYS will quarantine the area and monitor it for 5 years to prevent the spread.


An aggressive perennial woody vine with elliptic alternating leaves spiraling around stem.  Competes for sunlight growing to 60 ft., spreads through many methods including seed dispersal, above and below ground stems. Prefers open sun along forest edges. 

How to Identify

Flowers May – early June with bright reddish-orange fruit in fall.  Elliptic to ovate leaves are alternate and spiral evenly around the stem and have a serrated edge. Stems vary in diameter and can be up to 6+ inches.  Bark is striated and dark brown covered with lenticels. Causes damage to native trees & plants by girdling. Can be distinguished from native American bittersweet which has flowers and fruit at the end of its branches.


Small infestations can be managed by pulling or digging. Entire root must be removed to prevent re-sprouting.  Use of a leverage tool may be needed for larger plants.  Cut vines by hand prior to seed development and monitor site in fall. Do not compost. Spot treat cut stems with a foliar herbicide such as Glyphosate or triclopyr.  Has been found in S. L. region.

Scattered around our watershed


Spreads quickly by seeds and crowds out native wetland vegetations such as cattails, grasses, sedges and rushes. Older plants can produce up to 2 million seeds.  Impact on native wetland has been disastrous with PL stands virtually eliminating all other plants affecting the entire ecosystem.  

What is Purple Loostrife

An erect, hardy invasive herbaceous biennial averaging 3 + feet preferring open sun and moist soil conditions.  Grows along roadside ditches, marshes, river banks, edges of ponds.  Spreads by seeds.     

How to identify

It is typically found along roadside ditches or marshy areas and can grow 3 to 7 ft. tall. It has five or six petaled magenta flowers arranged close to the stem emerging in July and remain thru Sept.  Leaves are lance-shaped, typically opposite or whorled with smooth edge.  Stems are square / four sided and rigid.  As many as 30-40 stiff 4 to 6 sided stems may arise from one root system forming a large bushy cluster of stems.



Small infestations can be managed by hand-pulling. All root material must be removed, bagged and solarized* for two weeks before disposal in waste stream. Treatment should be before seed production which is in July.

Foliar sprays such as 1 to 3 % Glyphosate or Triclopyr for larger or dense infestations but not near wetlands and before seed production & before September. 

Manual and chemical means of removal are costly in terms of time and manpower and further disturb the environment.

ESSLA began a program to remove that continues today. Loostrife Beetles which can be purchased on-line (Galerucella) come from the natural range of purple loosestrife and feed solely on PL.    WCS&W also has a management program.

  * solarize-bag in plastic bags and leave in sun for two weeks. and burn or dispose in sanitary landfill. Contact ESSLA.  We have active program for releasing beetles on affected areas.

Expanding from Pa., downstate and Mass.   A threat- watch for!


Native to Asia and first appeared in the US in 2014, a highly destructive pest now in NYC, Conn. Southern Tier and in Hudson Valley. Feeds on wide variety of plants and crops such as grapes, hops (O NO!), apple trees, maple, walnut, and more than 70 plant species critical to NY’s agricultural economy.   SLF feedings stress plants making them vulnerable to diseases and attacks from other insects.  SLF also excretes large amounts of sticky “honeydew” which attracts sooty molds that interfere with plant photosynthesis negatively affecting the growth and fruit yields.   SLF travels easily and can hitchhike on any stationary object.  It can reproduce prolifically.

How to identify

Nymphs are black with white spots and turn red before transitioning to adults (active July to Dec.) Adults are approx. 1 1/2 in wide at rest with eye catching wings and lay eggs in Sept.  Eggs are laid in groups and each mass usually contains 30-50 eggs. Egg masses are brownish-gray, waxy and mud like when new.  Old egg masses are brown and scaly. Sap oozing or weeping from open wounds on tree trunk which appear wet and give off fermented odors are signs. SLF hatch in the spring as wingless nymphs feed and molt several times before finally turning into flying adults typically in July.   Spreads primarily through human activity. One inch egg masses may be anything from tree trunks, rocks to vehicles.   Freezing temperatures kill the adult, however egg masses may survive the winter. A preferred host is Tree of Heaven* and grape vines.


In addition to looking for the adults, look for egg masses.  NYS is implementing quarantines that restrict the movements of goods into NY from quarantined areas including nursery stock, firewood, stone shipments, etc.   If you think you found these, take pictures and contact DEC at   & NYS Dept of Ag. at- .  NYS has initiated an active tracking program to prevent establishment.  In addition to insecticides, a simple solution of ¼ cup liquid dish detergent and one gallon of water sprayed on heavy enough to coat them may be effective. 

SLf Egg Mass

Tree of Heaven

*Note- another invasive – Tree of Heaven, no angel, is the main host of spotted lantern fly.  Looks like sumac but grows to 70 ft tall.  Left- seeds, center- tree but may also grow as bush.  right- leaves and flower

Black and Pale.  Threatening our watershed, widespread thru NYS


Swallow-wort is a herbaceous plant and its vines spread quickly forming dense mats choking out large areas of favorable species interfering with forest regeneration.  There are multiple species.  Toxic chemicals in the plant make it poor forage for deer and other wildlife. It is similar to milkweed causing monarch butterflies to lay their eggs on the plant but the larvae die. Widespread thru NYS and found around Lake George.

What is swallow-wort?

Native to Europe, black and pale swallow-worts are herbaceous, perennial, twining vines. Escaped from Massachusetts Botanical Gardens, it thrives in wide range of soil moisture and light conditions and is found in many habitats including woodlands, fields and roadsides. It spreads quickly once established.

How to identify

Both species look similar when not in flower and have 3-4-inch-long by 2-3-inch-wide oval dark green leaves are opposite and glossy.   The leaves of the pale swallow-wort tend to be a lighter shade of green.  Flowers of both species are similar and star-like. Small five petaled star-like maroon to pale pink flowers are present in late May through July. Abundant seed ponds are smooth, slender and pointed in late summer and split open releasing innumerable downy seeds easily carried by wind. Milkweed like seed pods are 1 ½ to 3 inch long. Also spreads also by rhizomes.


Individual plants or small infestations can be dug by hand but only if removal is extremely thorough.   It can be difficult due to the deep fibrous root system. Remove as much of the root crown and rhizomes as possible before seeds form.  Burn all plant parts or bag and solarize* for two weeks.  When the plant is cut it resprouts vigorously making control difficult requiring herbicides for larger infestations.   Foliar herbicides can be sprayed on the vines after they begin flowering but not too early in the season as ample leaf surface is needed to absorb and effectively kill the roots.  May require repeat application   Areas that have been cleared should be planted with rapid growing native species.  Note- the seed pods can mature even after the plant has been dug up. 

  * solarize-bag in plastic bags and leave in sun for two weeks then burn or dispose of in sanitary landfill.

Observed around Schroon Lake


In 2020, we had member reports of white pines around the lake in various stages of decline. We have reported these to NYS DEC.  White pine trees are on the decline statewide, according to the state Department of Environmental Conservation.

Tall pines exhibiting decline

 DEC Scientist Response 9/2020: “DEC suspects they are victims of the white pine needle disease that is everywhere.  NYS is experiencing a landscape level white pine decline. The factors associated with the decline differ from the south to the northeast. Here, it is mostly caused by the needle disease (a complex of 4 fungal pathogens), poor site/soil conditions, wet, warm spring weather that makes disease load higher, periodic drought, and the presence of other insects and pathogens that stress the tree (Caliciopsis canker, white pine bast scale, and blister rust in some areas).

 Needle disease severity is much worse in unmanaged stands, overcrowded conditions. There’s not much to tell individual homeowners that are dealing with it. Solutions really only come from improved forest management. We are cooperating with many other states on a multi-million-dollar proposal to set up experimental treatments in state forests that show how management can mitigate the decline. It’s a massive, overarching project that also aims to do a lot of outreach and education, and assess timber market restrictions on white pine and generate new markets for it. We are also working with ESF* on this and has been scheduling regional meetings to discuss the white pine project, as well as provide other Forest Health updates. *ESF- SUNY Environmental Science and Forestry College.

With the needle disease, 2nd and 3rd year needles become infected and begin to discolor in May and June. By the end of June-July, the needles drop. The tree becomes defoliated, with only 1st year needles remaining green on the twigs. Trees eventually recover, but then experience the same defoliation the next year. Successive years of this will cause mortality. Weather patterns have changed, and are only making things worse. We have warm wet springs that favor the proliferation of the fungal spores. And then we have the periodic droughts that further stress the tree, unfortunately, we do not see that weather pattern changing any time soon.

The work we plan to do will focus on sites that are good for white pine. I think we will have to get used to just not having it as widespread as we do now. Trees on good sites with good management will probably persist, but trees on poor sites will eventually succumb to the disease.”


Report to NYS DEC

DO NOT TOUCH THIS PLANT   In our watershed!


Poses a threat to human health as the sap causes a painful rash and blistering from the sap that persists for months+. The sap contains chemicals called furanocoumarins which can make skin vulnerable to sunlight / UV radiation.   WP rash can last up to 6 months and may require medical attention. GH reaction can last years.


Wear protective clothing (PPE) – gloves, long sleeves and long pants when managing.  Treat like poison ivy!   

What is Wild Parsnip

A widespread herbaceous biennial invasive herb from Europe and Asia, it has become naturalized in North America. It thrives in full sun along roadsides & fields.  Biennial means it only lives two years.  The first year it has a rosette of compound leaves and the second year it flowers and sets seeds which is how it reproduces.

How to identify Wild Parsnip

2 to 5 ft tall, has hollow grooved stems, alternate compound branched serrated leaves that look like celery leaves. Leaves are yellow-green coarsely toothed with 3-5 leaflets. Flower stalks develop the second year. Blooms in June thru August with small, five petaled yellow flowers arranged in a flat topped, 2 – 6” broad umbrella. Taproot is long cone-shaped and thick.  Note- Queens Ann Lace looks similar but has white flowers.      

WP flowers

WP leaf

WP celery like stem 

Severe rash from Wild parsnip

Wild Parsnip Look a-likes

Queens Ann lace flowers may also cause skin irritation.  Cow Parsnip also contains furanocoumarins.  Giant Hogweed (invasive) is also reported in the Adirondack and is also a dangerous plant.  

Left: Queens Ann Lace (white flower)  Right: Cow Parsnip (white flowers) 

Left: Giant Hogweed- White Flowers, do not touch! Right: wild parsnip yellow flower

What to do / Help / Controls

Wild Parsnip control is fairly easy as it is a biennial but steps should be taken before seeds develop in July.  Repeated cutting the plant may be is very effective, BUT READ CAUTION BELOW! Follow up with repeated surveys as seeds (seed bank) in the ground can last for a long time. It is important to remove infestations while they are small and not well established. If cut too early while plant is flowering, new flowers will form on lower branches.  But cut seed heads before the seed matures and becomes dry to prevent the plant from shedding seeds while you are removing the head. Monitor site each year.  

CAUTION- Wear protective clothing – gloves, boots, long sleeves and long pants, eye protection, etc. when managing.  Treat this as worse than poison ivy!         

DO NOT use power equipment which will cause sap spray. Use PPE– rubber boots, long sleeve shirts and long pants, rubber gloves, eye protection, rain suit, etc. Synthetic water-resistant materials are best as cotton and linen fibers can soak up sap and be penetrated by plant hairs.  Use long handle cutters to stay far away from the plant as possible. Do not touch your face. Have a bucket of soap and water with you to immediately wash both during management and when finished.  Use the cutter or other tool to pick up the cuttings, not your hands.  A helper to manage the cuttings when bagging is recommended. Use a garbage pail or container to hold the plastic bag to prevent accidental contact when bagging. When done, wash all tools, equipment & clothes separately. Shower when done even if you think you have not had contact with the plant or sap. If contact with the sap occurs, wash the affected areas thoroughly with soap and water, and keep covered for at least 48 hours to prevent a reaction.  The sap is very clear, almost like water, and you will not know that you have had contact.  Even brushing up against the plant will transfer the sap.  If a reaction occurs, keep the affected area out of sunlight to prevent further burning and use sunscreen on affected areas.      Serious burns- see a physician.  

Selective herbicides such as 1 to 3 % glyphosate or Triclopyr foliar spray may also be carefully applied in May & June.  

Removal of cuttings (with or without seed heads)- Solarize pieces in plastic bags (clear preferred) for two weeks and leave in sun which will destroy seed viability. Recommend double bagging as stems may puncture the bag making others at risk.  After two weeks, take to a sanitary landfill. 

Giant Hogweed

Unlike WP, hogweed is a long-lived perennial plant.    It is found in the Adirondacks and NYS is actsively managing.          

 Guidelines for Giant Hogweed-  https: //  . 

GH is more dangerous than WP

Burns from Giant Hogweed sap can cause rash for 3 years or more.   Do not try to remove by yourself.  Giant Hogweed is of so much concern that NY established a hotline 845 256 3111 to report it, or email to;    Have location information available.  Giant Hogweed is widespread throughout NY.

Tips for using herbicides & pesticides

Try mechanical removal techniques first such as cutting, pulling up by roots, etc.  Burn or solarize* for two weeks before disposing. A  herbicide alternate is a 75 % solution of 20/30 % concentration vinegar (not avail. in grocery stores but found on line), 25 % water, add ½ cup of salt and 1/4 cup dish detergent/ gal.. Use a 1 gal. pump type sprayer to cover all leaf surfaces.  Be careful- this solution is acidic – use protective eye and skin covers and be careful of overspray.   Hire an applicator if you need support.

No one likes to use herbicides but- Safety First– be sure to use protective equipment.  Do not use near water or wetlands or within 30 minutes of rainfall. Special permits & applicator certifications are needed for wetlands.   READ the label! Label information is law. Use only on your own property.   Foliar sprays are to be used evenly on the plant leaves. When you have large dense infestations, it is more efficient and uses less chemical to apply using a backpack or mist sprayer. Apply when there is no wind so as not to affect non-target plants when spray drifts.   Stem injections are used on plants in wet areas and Japanese Knotweed.  APPIP may be able to help with loaned injection equipment.

* solarize–bag in plastic bags and leave in sun for two weeks then burn or take to sanitary landfill.