ORIENTAL BITTERSWEET AKA Celastrus orbiculatus 

Welcome to the Scotland Invasive Plants Working Group.  If you have some time today, click on some of the other informative links. Thank you for your interest in eliminating invasive Oriental Bittersweet from our town land and your own land. 

A native of Japan, Celastrus orbiculatus was brought to the United States as seeds in 1879 by Samuel Parsons who it is believed purchased seeds from Thomas Hogg Jr who was living and working in Japan, and whose father had a horticulture business in New York. The seeds were grown at the Arnold Arboretum outside of Boston, MA. After about ten years, the plants were offered for sale by Samuel Parsons who operated Kissena Nurseries in New York. The plant appears in one of their nursery catalogs from the 1880's, where it was described as very decorative especially during the winter months with its colorful display of yellow and orange seeds extending along the entire vine.  Although it remains a very decorative vine today, its colorful and prolific yellow capsules with their orange seed containing fruits have scattered over the years and have grown into the tangled vining plants that appear just about everywhere in our landscape. At this point our fields and forest edges have become incredibly overgrown with Asian bittersweet. Its vines have climbed into the treetops killing trees by wrapping around them tightly and girdling them or with their weight downing tree branches and even toppling older growth trees.  As more Bittersweet seeds fall new plants sprout and continue forming an increasingly impenetrable tangle that shades out native plants. The reward for removal of this plant is allowing native species to return to the landscape and protecting trees at the woodland's edge. You will also realize improved esthetics given the ability to see more clearly into a woodland unencumbered with a tangled mass of invasive vines.  This will also allow for easier access for recreational activities.

HOW TO REMOVE

The good news is that with a bit of persistence, this plant is fairly easy to control.  Bittersweet can actually be eliminated from areas where it has become troublesome.  It is a matter of cutting the trunk portion of the bittersweet back repeatedly while also cutting the "tree ladder". The tree ladder being the lower branches on any trees growing near the vine that make it possible for the vine to climb into the tree canopy.  Though it can be done any time of year, it is sometimes easiest to begin the process during the winter months when the vine is most easily accessible. At this point cut the trunk of the vine and any surrounding lower tree branches.  There is no need to physically pull the vine from the tree branches.  In fact, doing so could damage the tree. The upper portion of the vine will die back and disintegrate surprisingly quickly once its connection to the roots has been severed.  If you can pull out the root after cutting the vine, that will be helpful in the plant's faster demise.  Repeating the process of cutting the bittersweet as it attempts regrowth several times during the summer months will continue to sap the plants strength.  Your persistence will eventually kill it.  If you want to ensure that this pant does not regrow from the cut stumps simply paint them with a concentrated application of herbicide.  Eventually you will be left with only young Bittersweet plants sprouting from fallen seeds, and these will be quite easy to pull out by the roots.  They have a bright orange root system easily recognized.  I often hang the young plants I remove in the branches of a nearby shrub where they will they dry out and lose their vitality.  Of course you can also collect them, bag them up and dispose of them in the landfill. 

This invasive plant has no natural predators, so it is up to us to keep it contained within our landscape! 

 

 

BUSH HONEYSUCKLE AKA Morrow's Honeysuckle, Lonicera morrowii, or Lonciera tartarica, or Lonciera bella

There are a couple of invasive or potentially invasive bush honeysuckles living among us.  Technically they are or at least were two different species Lonicera morrowii native to Japan, Korea, and Northeast China, and Lonicera tartarica native to Eurasia.  Both were imported to the United States as ornamental shrubs.  The two are related and have similar growth habits, both reaching an average of 10 feet tall with a wide upper crown. These bush form honeysuckles are not to be confused with Japanese honeysuckle, also considered invasive, but which is a vine rather than a bush or shrub. As I am researching for this blog entry, and pondering which of the bush species we have, or if we actually have both, I learned that the two have actually cross bred on their own in a method called artificial hybridization (a cross consisting of two different species). The cross bred plant is called Lonciera bella. In mid-spring, even though I know I should, it is difficult to hate these invasive family of bush honeysuckle plants.  This is the time of year, early May, when the bushes are loaded with incredibly fragrant flowers.  When in bloom, during a span of a good two weeks, you can't help but detect their powdery fragrance in the air. The flowers form in clusters starting off white and maturing to pink or yellow.  After the flowers are done blooming, the red or orange fruit forms, also in clusters.  The fruit is just as prolific as the flowers and therein lies the problem.  As the fruit falls to the ground, the seed contained within germinates.  The colorful fruits are also carried away by birds or small mammals, The seeds within the fruit pass through their digestive tract and are later deposited elsewhere amid their droppings.    As a rule, bush honeysuckle prefers to grow in open sunny fields or on the forest edge.  Birds and animals transport the seed further into the woodland where the bush will grow if there is an opening in the tree canopy that lets in the sunshine.  If growth from seed dispersal is successful bush honeysuckle will colonize that forested area too.  I have personally witnessed this plant rapidly take over former pastureland and also witnessed its creep into the adjacent forest. 

HOW TO REMOVE

The plant has a relatively shallow root system, making smaller examples fairly easy to pull especially after a good saturating rainfall.  If there is not an overabundance of bush honeysuckle to tax your strength, larger plants can be removed by cutting the plant's branches back and using a pickaxe or similar tool to undermine the root collar.  Sounds fun huh?  If you can get under it, you can remove the shrub with the root collar attached leaving the remaining roots behind.  After all that work it is good to know that at least this plant will not grow back from the long trailing parts of the roots that remain in the ground.  

If the infestation is larger, there are several solutions you might consider.  During the plants summer growing season, cut back all of the branches as low to the ground as possible.  This can be done with loping shears, or with a battery or gas-powered brush cutter, the gas version is cleverly nick named a gas goat! After cutting back the shrub, it is essential that you treat the remaining cut portion of the branches with an herbicide such as glyphosate, otherwise the shrub will aggressively grow back, and all of your hard work in cutting will be for naught.  The herbicide will prevent regrowth of the branches.  If an infestation is especially heavy an autumn foliar application of herbicide is recommended.  The plant keeps its foliage after any native plants or trees have died back so a late in the season treatment will more specifically target bush honeysuckle and spare any native species.  You will need to keep an eye on the area and perhaps treat a second time, but rest assured, you will gradually win the fight.  I don't want to leave out goats as another possibility here.  Provided bush honeysuckle has not been chemically treated prior it is safe for most goats to consume this plant in addition to other foods that generally in their diet.  

JAPANESE KNOTWEED AKA  Reynoutria Japonica, Fallopia Japonica

Almost every time I search for or take a photograph of the "invasive plant of the week" I am surprised by the plant's decorative potential!  The first photo is a good depiction of what the plant looks like at its present stage of its growth.  The second photo shows the mature plant in flower.  Although commonly called Japanese knotweed this plant is native to all of Eastern Asia. When in bloom the plant is positively loaded with gorgeous foamy white flower spikes that are attractive to pollinators.  An interesting note is that the young shoots and leaves of this plant are edible.  The shoots have a tart flavor similar to rhubarb and can be used as its substitution in recipes.  Should you be interested, recipes for knotweed, including knotweed wine, sorbet, and chutney can be found on the internet.  If you are choosing to harvest this plant for consumption, be certain you are harvesting the correct plant and that it is not from an area that has been treated with chemicals!

How did this plant arrive on our shores?  Female plants, thought to be sterile, were first introduced in the prestigious Kew Botanical Gardens in England in 1850. During the 1880's it became a desirable exotic plant for inclusion on the property of several expansive Long Island, NY estates.  It appeared as an ornamental plant in nursery catalogs until the latter 1930's.  Even then it was under watchful surveillance as a suspected outlaw and garden escapee.  

How did this plant arrive in Scotland, CT?  One of its adapted uses was for erosion control.  Stands of it were installed on highways and state roads.  This is likely the cause of its present bounty along some of our roadsides in town.  When traveling through Scotland on our town and state roads, you can't help but notice vast colonies of knotweed so dense that nothing else grows among it.  The reason for that is that it, like some other invasive plants, it has an allelopathic superpower.  The plant's roots and other decaying plant parts exude chemical compounds that prevent other plants from growing in its midst.  The plant also has dense lush upper leaf growth, keeping any brave potential competitors from finding the sunlight they require to grow.  This is how Japanese knotweed quickly creates a monoculture.  It crowds out native species that many of our native insects and animals require to thrive. You may wonder, how did only female plants reproduce so prolifically?  There are a couple of answers to that question.  One is that are other several species of knotweed and if one of these happens to be located nearby, there is a potential for cross pollination, which would create viable seed.  This plant, however, spreads primarily through its root system, technically called a rhizome system.  Rhizomes are roots that grow horizontally periodically sending up new growth. In the case of knotweed, these rhizomes are hardy enough to penetrate through any small cracks in a house foundation or any pavement potentially causing severe damage.  In some areas, the presence of this invasive plant is actually having a detrimental effect on real estate values.  Although the plant goes dormant in the winter months and temporarily dies back when there is a spring freeze, the rhizomes remain viable underground.  Even if plant growth is suppressed and no additional nutrients are added, it is said that the rhizomes are capable of remaining viable for up to 20 years!  Any small bits of this powerful rhizome system accidentally transported by a snowplow, brush cutter or unintentionally by a garden shovel will readily form a new ever-increasing colony.  If this plant colonizes along our waterways, the diverted water flow caused by dense stands of Japanese knotweed can cause flooding and potential bank erosion.  As riverbanks erode, segments of the plant's rhizomes could be transported downstream.  Rivers brooks and streams are a virtual highway for the plant to follow. Elimination of this plant should definitely be a priority!

HOW TO REMOVE

Take a deep breath!  This is going to be a difficult but not impossible task.  It is one that will likely involve a combination of techniques possibly including the use of herbicides.

If you want to try a method that does not use herbicides the present recommended method is to cut the plant back three times during its growing period.  Once in June, again in July, and last in late August.  The repeated cuttings are meant to keep the plant from flowering.  Cut as low to the ground as possible.  The stem has what look like joints or notches which are called nodes.  You want to cut the plant beneath the plant's lowest node.  Cutting the plant numerous times also helps to reduce the plants energy transfer to its rhizomes.  After cutting, the knotweed patch can be covered with black plastic carefully weighted around the edges.  The cut stems should be placed in contractor bags and disposed of in regular trash.  Do not compost them, as any pieces of attached rhizome could sprout in your compost pile! This method of removal will need to be repeated for at least three years.  Continue to monitor the area as this plant can be very persistent. 

If you are comfortable using herbicides, The recommended method is to cut the plant back to 2 to 3" in late May or June, and then let it grow until August.  Spray before the plant flowers using glyphosate with an added surfactant or with triclopyr.  Many pollinators feed on this plant so spraying either before flowers form or after the flowering stage is complete is essential so as not to harm them. Cutting the plant back in the spring reduces the height of the plant, therefore the amount of chemical needed for coverage.  The same protocol will need to be repeated the following year.  After the second year of treatment, plant the area with some native species such as Joe Pye weed to reduce the growth of Knotweed.  You will likely need to continue treatment every two years following the second treatment.

Biological Control:  An insect called Japanese Knotweed Psyllid or Aphalora itadori was introduced in 2020 as a possible biological control method.  The insect is host specific to Invasive knotweed.  During all of its life stages, the insect consumes the sap from the leaves and stem.  This in theory weakens the plant.  In the United States in 2020, several releases were done in areas including Rhode Island and Massachusetts.  Other releases in the UK and Canada done back in 2010 have resulted in populations of the Knotweed Psyllid having established a presence in that area. It remains to be determined how successful the release of this insect in the United States will be.

JAPANESE BARBERRY AKA Berberis thunbergii

 Welcome to the Scotland Invasive Plants Working Group website!  Earlier posts explain the different types of herbicides and other general information on invasive plants.  There are also links that provide native plant substitutions.  Visit the links on the sidebar to the right for even more information.

The wanted poster you clicked on brought you here because you expressed an interest in eliminating invasive Barberry from your land. First a bit of its history, as it is always best to know your enemy!

This plant, like many invasives, has virtually naturalized itself throughout our uncultivated landscape.  At this point it is difficult to believe it is not a native species.  Japanese Barberry was brought here in 1875 as a landscape plant.  The ornamental version, obviously from Japan, was desirable for its dark red leaves and colorful berries, it made a pretty hedgerow, and with its thorny branches a hedgerow that was virtually impenetrable, an attractive fence so to speak. By the early 1900's it had already begun to escape cultivation.  How did that happen?  The plant's pretty bright red seeds made enticing food for birds, and small animals. The seeds were carried with them in their digestive tract and eventually deposited in their droppings in forests and fields, and there the seeds germinated.  The new plants that grew from these seeds often lost their desirable colorful foliage, but they kept their thorns and many of their other characteristics, such as early foliage lasting later into the growing season, and of course the abundant colorful red berries so appealing to the birds.  Barberry's spread throughout the landscape continued, in areas not maintained regularly such as open fields, forests, and roadsides. The plant has no natural enemies.  Its thorny branches make it an unpalatable food source to grazers such as deer.  The plant grows with a branchy spreading type canopy that shades out native plants.  As its taller branches fall to the ground some eventually take root.  This is called creeping or prostrate growth and also called vegetative propagation.  When this type of propagation occurs, invasive Barberry begins to make an impenetrable wall.  The plant at any stage, but especially this one, creates a safe haven for mice and other rodents.  While that may be a good thing for the rodents.  It is not a good thing for us. Rodents are carriers of ticks, so an increase in their numbers also dramatically increases the number of disease carrying ticks in the landscape. An increased tick population escalates the number of tick-borne illnesses.  Barberry's branching habit combined with its early growth and late dieback prevents many native plants and trees from establishing themselves.  If left unchecked barberry will create an inadvertent monoculture, an area where Barberry is the only plant growing, excluding the growth of any other plants.  Thick infestations of barberry can make it difficult for a person to navigate through the forest.  One of the rewards for this plants removal is knowing that you are reducing the tick population.  You will also be helping to create a landscape that contains more native plant and animal species, and one that encourages recreational activities such as hiking.  

HOW TO REMOVE

If you are fortunate to have only several of these invasive shrubs growing on your property, the good news is that there are a couple of relatively easy solutions their removal.  If you take a steel garden rake and push the branches forward, you may be able to get a shovel under the shrub and dig it out.  Try to remove all of the roots to prevent regrowth.  very small plants can simply be hand pulled.  Another removal method that can be performed any time after early spring growth has occurred is to cut the branches as close to the main stump as possible with loping shears. An application of concentrated herbicide must be applied to the stump soon after cutting to help prevent regrowth.  If you do this too early in the spring, the plant will be sending nutrients from the roots to the leaves.  Wait until the plant is fully leafed out.  Itis at that point that flow of nutrients reverses and the herbicide will be carried to the roots.  If you have a larger infestation of Barberry, a foliar herbicide applied during the plants growing season may be the best solution.  If you are not comfortable handling herbicides, or if you have a very large infestation, it may be time to call in the professionals.  They have the capability of using a forestry mower, applying herbicide over a large area, or perhaps even performing a prescribed burn. 

Beware!  Japanese Barberry cultivars are still being sold in Connecticut.  Before considering them as an ornamental, consider planting a native shrub that does not encourage the presence of ticks!

 SOME OF THE NECESSARY TOOLS FOR THE JOB

I am hopeful, to say the least, that by now you are considering the removal of some invasive plants on your property.  Here are a few of the tools recommended for that job.  I really like Fiskars extendable power lever loping shears.  They are presently available at Ocean State Job lot at a very reasonable price too.  They are light in weight and believe me, they take a lot of abuse!  Actually, another tool manufactured by Fiskars, and also available at Job Lot is a nifty narrow trowel with a serrated edge like a knife.  It is good for digging and the durable and sharp serrated edge is also perfect for cutting roots and even semi-woody stems. A large spade form shovel is also a tool you will find useful, as it will give you more leverage for removal of larger plants and shrubs

One of the methods that I like for control of invasive shrubs is the cut stump treatment.  As much as I would like to use this method now when all the shrubs are beginning to green up, it is a method best performed in late summer and fall when the plant is transitioning its nutritive supply from the leaves back to the roots.  After cutting the stump close to the ground you apply herbicide directly to the cut edge.  You will need a good pair of chemical proof gloves, and I would recommend a mask and goggles as well. For the actual application of the herbicide, you will need at least a spray bottle for small areas or a backpack sprayer to carry ample amount of herbicide to spray on the cut stumps in larger areas of infestation.

 THINGS ARE FINALLY BEGNNING TO GREEN UP, BUT...

It looks like spring has finally arrived!  As always, I have been watching the roadsides in eager anticipation.  Here's the thing though, I used to think it was a good sign when I saw early hints of green in the scrubby growth along the wood line, but as I have been learning more and more about invasive plants, I have come to realize that most of the early greening that I see is the result of invasive plants coming to life.  Their early growth is but one of their methods of gaining a foothold over native plants which are often a bit slower to awake from their winter slumber.  While you are on the road, take a glimpse into the forest.  In the understory you will see a froth of green foliage.  Much of what you see is the emergence of leaves on the Japanese barberry shrubs.  It is especially at this time of year, when they are first leafing out that you can see how they are filling in spaces between all of the trees.  You can imagine how dense, and impenetrable these shrubs will eventually become if they are allowed to continue their unbridled growth.  The multiflora rose is another equally virulent offender.  Soon I will be posting articles describing some of the most effective methods for the control of these and other plants on the invasive species list.  Stay tuned.

 STATE OF CONNECTICUT TO CONDUCT MORE CONTROLLED BURNS  

Copy and paste the link below for more info from CT DEEP

https://portal.ct.gov/deep/news-releases/news-releases---2025/deep-to-conduct-prescribed-burns-at-six-locations-this-spring

 If anyone has actually been reading this blog you may be thinking "There she goes again.  She seems somewhat obsessed with the concept of controlled burns".  Maybe I should attempt an explanation.  Shortly after we moved here, I found my first Indigenous tool while walking in one of the ploughed fields in town after a heavy rain. I felt a kind of awe at its discovery.  I never lived anywhere before where the evidence of past human occupation prior to the colonial era could be found on the surface right under my feet.  To be able to just pick it up and handle it was an extraordinary feeling.  Most often primary source material is a handwritten document. In this case the primary source material was made of stone.  Thousands of years ago a person's conceptual design and physical energy went into creating that stone tool, and thousands of years later I was holding it in my hand exactly as the day it was made. It gave me a feeling of connection to the past that I can't quite describe without sounding cheesy. I have been very interested in the life and culture of the Indigenous population that lived on these lands ever since.  Holding that tool encouraged me to take a fresh look at history. In school we were of course made aware that there were Native Americans here predating European settlement, and we learned something about how the two populations interacted, but actual Indigenous culture was a topic barely glossed over in many classrooms, at least during my years. European culture versus Indigenous culture was a clash of two very different life philosophies. In the instance of our country the primary culture ended up evolving in the European manner. Forests were clear cut and farms laid out in perfect squares.  Vast numbers of animals were killed solely for their fur.  Permanant structures were erected and then came the industrial age with its dams and mills. We can all see where it has led us today.  Nothing is perfect in any culture. I am not idolizing or elevating the Indigenous culture to any godlike status, surely it was not perfect, but it does seem obvious that Indigenous people had a way of connecting with their environment and for the most part adapting to it rather than making drastic alterations to the environment forcing the environment to adjust or adapt to their human presence. Yes, they made beneficial changes to their environment which allowed them an upper hand in hunting and growing crops, but close observation of their environment was one of their strengths.  Observing natural phenomena such as what the impact to the land was after a lightning strike and subsequent brush fire and watching closely which plants perished and which useful plants grew more with more vigor, carefully watching the ways fire improved the land that provided their sustenance.  They were then able to simulate that phenomenon using fire, a natural method borrowed from nature, to duplicate the results. It has been well documented by early European settlers upon their arrival that many old growth forests were clear of underbrush providing an almost park like setting, and that there were open grassy fields as well as agricultural fields planted with crops such as beans and corn.  Even Thoreau, in the mid 1800's, 175 years ago, after the first industrial revolution, mourned the loss of the open old growth forests and the variety of wildlife they once harbored. I encourage you to visit the areas the State of Connecticut DEEP is attempting to restore using this ancient method.  It will be interesting to observe the changes to them as they appear.