Yellow flag iris AKA Iris pseudacorus

Yellow flag iris is native to Europe, Western Asia and Northwest Africa.  It was brought to the United States, as an ornamental plant, during the second half of the 1800's. Soon after its introduction the plant began to escape cultivation.  It was a desirable ornamental loaded with cheery bright yellow flowers that that unfurl in late spring. It is also a very hardy plant with a tough fibrous almost woody rhizomatous root system. The plant spreads vigorously from the root as well as from the multitudes of disk-shaped seeds contained within its numerous seed pods.  In the right conditions, especially in a wet bog like setting, the plant can reach a height of four to five feet.  

When I first saw this plant on the Connecticut Invasive plant list, I was in denial.  I maintain an island of flowers along a roadside.  When I began planting the island with flowers some 20 years ago, I wanted to plant a variety of hardy perennial plants that I thought would be impervious to salt, sand, full sun, and capable of survival being watered solely by rainfall, rather harsh growing conditions.  This pretty flowering plant was already growing and thriving on my property, and it seemed to fit the bill, so it is one that I choose to plant in that garden.  Fortunately, perhaps due to the fact the irises are growing in an island surrounded by asphalt, they do not appear to have escaped.  I will mention here that it is not legal to sell this plant in Connecticut, however this plant is still available for purchase online.  There are many other options.  Do not add this plant to your landscape!

Yellow flag iris can often be found naturalized growing in wetland settings, along brooks and streams or in marshes.  In a brook setting you can easily imagine the numerous seeds and seed pods floating down stream where they eventually germinate and create more colonies. Colonies of this plant can alter the flow of water and cause flooding.  In addition, invasive non-native plants have the ability to crowd out native plants that wildlife depends upon to thrive.  In the case of yellow flag iris, the entire plant is poisonous as a food source for animals. Perhaps another reason it remains presently contained within my island of flowers. Soon I will be attempting its removal from that garden, though I will miss its bright sunny presence next spring. I am certain I can find other non-invasive irises to plant in its place. 

HOW TO REMOVE 

For small infestations hand digging with a good strong sharp shovel is best.  The fibrous roots need to be removed in their entirety to prevent regrowth.  Gloves are recommended for handling the roots as resin contained within them can cause skin irritation.  Do NOT use livestock to graze on this plant as it is poisonous for them as a food source.  

If the plant is growing in a pond, First remove and bag any seed pods, then cut the plants at their base below the water line.  Do not compost the seed pods!  That will just spread the plant!  Another method is to cover the colony with a PVC pond liner or heavy tarp being sure to eliminate any air pockets.  Extend the cover a foot beyond the colony.  Bury the edges of the covering and weigh it down securely. It is said that the PVC pond liner can inhibit gas exchange and kill the colony in as little as four to six months.  You will need to monitor the area afterward to be certain there is no post emergence.  

If the plant is growing on dry land, and you want to try an herbicide, a novel method for application on this plant is called wick wiping.  It involves securing a sponge with an elastic band to each end of a pair of kitchen tongs.  Since iris is a monocot like grass is, you need to select a non-specific herbicide that kills grasses as well as broad leaved plants.  Glyphosate is one that is recommended.  You then dip the sponges in the diluted herbicide and wipe the leaves with the sponges on the tongs.  This method cleverly prevents any overspray.

If there is a large colony growing in a wetland or pond setting, there are several water specific herbicides available that are said not to harm wildlife.  You will first need to check to see if a permit is required for their application.

                                   Wineberry AKA Rubus phoenicolasius 

Wineberry is a plant native to China, Japan and Korea.  It was introduced to the U.S. in the 1890's as a breeding stock for raspberries. It is still being used in the United States for that purpose today, though great care is now taken to contain it.  Since its introduction it has spread vigorously throughout the U.S. beginning its spread in the Appalachian Mountains and continuing to spread from there.  At this point wineberry is considered invasive in many states including Connecticut.  The plant grows rapidly forming dense thickets, crowding out native species and filling disturbed areas, preventing other native plants and trees from gaining a foothold. So many ash and oak and hemlock trees have died and fallen throughout our forests in the last several years.  Their loss has left areas of the forest floor open to the sun. Wineberry, barberry, winged euonymus and other invasive shrubs and plants are more than happy to fill those sunny vacancies.  Once they do, the dense shady areas they create can deter those trees from germinating and repopulating our forests. 

Wineberry is related to roses, and of course raspberries.  It is in the Rosaceae family.  When you pick a raspberry or a wineberry, you may think of it as a single fruit, but it is actually a cluster of small fruits, each with its own seed inside capable of germination. The botanical term for this type of fruit is aggregate fruit.  Wineberry is capable of propagating not only by its numerous seeds, which are often distributed throughout the landscape by birds and animals. but as with many other invasive shrubs, it is also capable of spreading through vegetative propagation, when tips of canes that have fallen to the ground take root. In addition, it spreads by shoots coming up from lateral growing roots.  With all those methods of propagation, you can see how this shrub can readily form a thicket. 

Here are some distinguishing characteristics that should help to identify wineberry from native varieties of raspberries.  When you examine the cane of a wineberry, you will notice several longer stiff prickles along the cane along with multitudes of fine long red hairs that make the canes appear red from a distance.  The leaves of wineberry are white on the underside and feel a bit waxy.  They appear on the branches as three heart shaped leaflets growing in alternate fashion along the cane.  As is true of many varieties of raspberries, the first-year canes, called primocanes, grow tall and straight and do not bear flowers or fruit.  The second year those canes, now called flora-canes, form side shoots and those side shoots bear flowers followed by fruit.  The small flowers grow in clusters.  Each five petaled flower is pink to purplish red.  The fruit forms within a distinctive sticky calyx that is covered in fine hairs which exude a sticky fluid.  Because of its sticky nature, the calyx will sometimes have small insects stuck to it.  When the fruit is fully ripe, it is red and also a bit sticky.  When picked, the fruit is hollow on the underside just like a raspberry.  After the fruit is plucked from its hull, the hull left behind on the plant is yellow versus the whiter color hull on a raspberry.  The taste of the fruit is said to be similar to that of a red raspberry but with slightly tarter flavor. Wineberries are perfectly edible and fine for making pie, and jam or, as the name suggests, wine.  

I have yet to encounter this plant or taste its fruit, but I've always found that once you learn about something it is then you begin to notice it, and in some instances, it may have been right under your nose all along.  I was somewhat familiar with this plant from a Facebook post from a group covering native and non-native plant identification.  Now that I have learned even more about this plant, I will definitely be keeping an eye out for it and hope you will too. It is entirely possible that wineberry is yet another invasive plant presently growing somewhere in our town.  We do not want to encourage its growth!

HOW TO REMOVE

Small colonies can be dug out fairly easily as the root system is not terribly tenacious.  Cutting back the foliage repeatedly will also eventually deplete the root system of nutrients eventually killing the plant.  If it has already formed a large hedge or thicket, you may want to consider a foliar spray with an herbicide.  Keep in mind foliar herbicides should be applied late in the growing season when the plant is sending nutrients from its foliage back to the root system.  Though you might believe the best time to try to eradicate a plant with a foliar herbicide is in the spring, when the plant is first emerging, and still small, it is at that point that the nutrients are traveling in the opposite direction from the roots to the leaves making the herbicide relatively ineffective.  It is in the late summer when the process reverses and nutrients are being passed from the crown of the plant back to the roots for winter storage that a foliar spray should be applied because the plant is in the growing stage where it will carry the herbicide to its roots where it can effectively work to kill the plant.

                         

  Watercress AKA Nasturtium officinale  

When I first saw this plant growing along the edges of Merrick Brook years ago. I thought "Oh wow, it's watercress!"  Now that I have been researching invasive plants for a while, I have to admit I was pretty disappointed to find this plant on the list of potential outlaws. It's Latin name Nasturtium officinale makes you wonder what they were thinking when they named it. Its flowers and foliage don't resemble those of a Nasturtium in the least.  They are distant cousins though, and both plants have that pleasant peppery taste when nibbled.  You often find the word officinale incorporated into part of a Latin name for a plant. It simply means it is a plant used in medicine herbalism or cookery.  Watercress, which is native to Eurasia, is one of the oldest known leafy vegetables to have been consumed by humans.  Now found in many locations across the globe, it was introduced to America in the 18th century.  

The plant is in the mustard family, and like others in that family, it is considered a cruciferous vegetable because the four petals of the flowers, which form in clusters, resemble a cross or crucifix.  If you look closely at the flowers of Garlic Mustard, as well as kale, turnips, broccoli, and radishes you will see the same flower formation.  All of these are considered cruciferous vegetables, and being so, they are quite healthy veggies to consume. I am going to insert a consumption warning here.  

If you are planning to eat watercress found in the wild, first of all, as with any plant you might be foraging, be certain you have the proper identification.  Also, in the case of watercress, be certain you are harvesting from an extremely clean water source.  Otherwise, the plant could contain giardia, a parasite that beavers are notorious for carrying.  Perhaps even worse, if the water has been contaminated by manure, you may ingest a parasite called liver fluke, and that doesn't sound at all pleasant!  

The peppery flavor of the plant is actually part of the plant's defense system.  It is caused by two compounds contained within the plant that combine whenever the plant is injured.  For all its attempts at self-defense though, that zippy flavor does not stop ducks, muskrats or deer from eating the leaves.  Those particular herbivores seem to have gourmet taste, and they are one of the contributing factors to the plant's redistribution and spread along our waterways. Watercress is also a prolific producer of seed, which is another means of its spread. Portions of the plant can also be dislodged and carried downstream during heavy water flow where they can take root and form new colonies.  

I have never seen an exceptionally large colony of this plant in Merrick brook, or in the Shetucket River, but this plant does have the capacity of creating a rapid growing blanket of greenery that floats on top of the water, crowding out native vegetation and many of the things that rely on native vegetation to survive.  A large enough mat can deplete the water of oxygen. If you have a large infestation of this plant, you should make an attempt at its control.  

HOW TO REMOVE

This plant can be hand pulled very carefully so as to capture the entire root system and prevent regrowth.  After being pulled it should be bagged and removed from the site.  It is fine to just deposit it in the trash.  

When writing about various invasive plants and including a "how to remove" section I decided to include all of the recommended options provided by reputable sources, so please don't shoot the messenger! I am not a big fan of using herbicides and putting them in direct contact with a body of water seems almost unconscionable, but there are instances when their use is the lesser of two evils, and there are herbicide mixtures designed specifically for aquatic use. If you are dealing with a particularly large infestation of watercress that is crowding out other plants and depleting the water of oxygen, you may want to try one of the aquatic herbicides

     Autumn Olive AKA Elaeagnus umbellate & Russian Olive      Elaeagnus augustifolia 

Autumn olive and Russian olive are both hardy branching shrubs that grow in a form that resembles bush honeysuckle.  All of these shrubs produce a profusion of berries. Bush honeysuckle, autumn and Russian olive are all considered invasive, but should you wish to identify them, an easy way to tell the "olive" shrubs apart from bush honeysuckle is to examine a branch.  The bush honeysuckle has leaves that grow in opposite fashion, directly across from each other along the stem.  Both the Russian Olive, native to Eastern Europe and Central Asia, and Autumn Olive, native to China, Japan and Korea, have leaves that grow in alternate fashion along their stems.  If you snip a stem or branch from any honeysuckle, you will find a tiny hole in the center of the branch.  The branch of a honeysuckle shrub has a very narrow hollow portion in the center.  

Russian Olive was introduced in the early 1900's and Autumn Olive a bit earlier around 1830. Both were imported for their value as a wildlife habitat, as well as for erosion control, and their ornamental appeal.  The two "olives", which are technically not olives at all, readily escaped cultivation.  At this point they have both been declared an invasive species over most of North America and Europe. Positive identification of which "olive" species you are dealing with does not really matter because elimination strategies for either plant are similar.  In fact, the plants themselves have more similarities than differences.  For the sake of accuracy though, you can tell the two apart most easily when the shrub is in either its flowering or fruiting stage.  Autumn Olive has white or creamy yellow flowers.  When the fruit is mature it is red with silvery speckles or scales on its skin.  The Russian Olive has brighter yellow flowers and a fruit that is more yellow orange with silver speckles when mature.  Other more subtle differences are in the shape of the leaves, with the leaves of Russian Olive narrower in form than those of the Autumn Olive.  Russian Olive foliage appears more silvery due to the fine fuzz like hairs on both the top and bottom sides of the leaves whereas Autumn Olive has fuzz primarily on the underside of the leaves.  Both of the shrubs have thorns but they are fewer in number on Autumn olives.  Both bear abundant fruit which is edible and nutritious for birds, wild animals and, when the fruit is fully ripened, people as well.  The fruit of either variety is usually fully ripened by October.  Autumn Olive fruit will be bright red with silvery specks.  It usually gets sweeter after a frost and it remains on the shrub through November.  The fruit of Russian olive may not have as desirable a flavor or texture.  If you intend to eat this fruit please be certain you have made a positive identification.  Do not confuse the plant with bush honeysuckle as that fruit considered toxic for human consumption.  If these plants provide such an abundant food source, why should we attempt to eliminate them?  The thing is with their rapid growth and prolific seed production they out-compete many native plants.  They also have the ability to increase the nitrogen level in the soil in their vicinity.  The increased nitrogen level benefits autumn or Russian olive, but other plants that are native to our region may not find all that nitrogen beneficial.  

HOW TO REMOVE

If you happen to have them, goats really like to forage this plant.  They also love Multiflora Rose, and a variety of other invasive species.  If you allow goats to consume Autumn or Russian Olive plants while adding other non-invasive forage options, eventually the alternative forage options will crowd out the Autumn or Russian Olive eliminating those invasive plants.  If you are not fortunate enough to own goats, hand pulling of small plants is recommended.  This is best done after a good soaking rain which softens the soil allowing the roots to be pulled more easily.  Try to remove the entire root system as this plant may regrow from fragments left behind.   Repeated cutting of shrubs will eventually deplete the root system, but you need to be vigilant, continually cutting back regrowth.

During their active growing season, especially during the later part of their growing season when the crown of the plant is passing nutrients back down to the roots, the shrub should be cut as low to the ground as possible.  Follow up with an herbicide application to the cut stump to prevent regrowth.  Triclopyr is the preferred herbicide to use to eliminate this plant.  It should be used in its undiluted form for the cut stump treatment.  Another method for herbicide application is to prune the shrub back to a lower level and use triclopyr as a foliar spray when the plant resprouts and has fully formed leaves.  The leaves are what take in the poison.  Cutting the plant back first allows for the use of less herbicide during foliar application and it also makes it easier to reach all parts of the plant with the spray.  Be sure to follow the dilution instructions and all other instructions on the product's container.  Always wear protective clothing, and spray herbicide on a calm day.  

 Invasive Plant Walk Talk & Cut at the Scotland Public Library

On August 30, 2025, our group of twelve or so joined up with Rose Hiskes and Dr. Charlotte Pyle of The Connecticut Invasive Plant Working Group to learn more about invasive plants and native plants as well.  The day was clear and absolutely perfect. As we hiked along the trail, I came to realize how enjoyable it was to meet with like-minded people all of whom were well informed about the impact invasive plants are having on our landscape.  Rose and Charlotte were especially knowledgeable, providing us with botanical terminology and various ways to detect some of the invasive species no matter the season.  In addition to the invasive plants, they pointed out some exceptional native specimens growing along the trail.  

The trail along the boardwalk at the library is a soothing and peaceful spot.  The boardwalk itself is truly special, definitely worthy of preservation, as the boards used in its construction were purchased years ago by town residents and inscribed with their names or names of their loved ones, past and present residents of our town.  Unfortunately, over the years, the entrance to the boardwalk became so overgrown that you might not even realize the trail existed. 

After our informative walk with Rose and Charlotte, and a wonderful lunch which included a variety of delicious pizzas, a generous donation from our town's nip fund, we returned to the trail armed with energy, clippers, and various brush cutting tools.  About two hours later our group amassed a huge pile of invasive bittersweet, multiflora rose, and burning bush branches. I am excited to report that the opening to the trail is now once again visible!

After posting various "Wanted Reward for Outlaw Plant Posters" for invasive plants linking to articles this website, I was asked "What exactly is the reward?"  I can now affirm there are numerous rewards.  The camaraderie of working together with people is probably the most important one.  There is also the reward of accomplishment you feel when you step back and see the impact your work has made.  Then there is the reward of acquired knowledge.  In addition, a little bit of exercise can also be kind of rewarding.  Depending on which side of 60 you fall on, you might feel a tad achy the following morning from stretching to cut vines and from pulling out roots, but even that actually feels pretty good.

We will be meeting again in the not-too-distant future.  Feel free to join us next time if you missed the opportunity the first time.  I will keep you posted as to the date on the Scotland Residents FB page.  At the next meeting there will be no limit to the number of participants.  Stay as long as you can.  You don't need arrive at the beginning or to stay to the end of the work period.  Any help you can offer will be greatly appreciated.  Let's work together and get this trail back into shape!

Come Join Horticulturists Rose Hiskes and Dr. Charlotte Pyle at the Scotland Library!  Take A Walk and Learn More About Invasive Plants.  The program is free of charge, and lunch will be provided. 

On August 30th, 2025 from 10 AM to 1 PM rain or shine you are welcome to join The Scotland Invasive Plant Working Group, and our guests Rose Hiskes and Dr. Charlotte Pyle at the Scotland Library to learn about invasive plants. This program is limited to 12 participants.  Registration needs to be made by August 8th.  If you would like to attend, contact Rose.Hiskes@ct.gov to register.

Take a walk with us along the boardwalk trail through the woods at the Scotland Library.  We will be accompanied by horticulturists Rose Hiskes of the Connecticut Invasive Plant Working group and the Connecticut Agricultural Experiment Station and Dr. Charlotte Pyle a forest and landscape ecologist, and co-chair of the Connecticut Invasive Plant Working Group.  

The first part of the event will be an interesting learning opportunity with Rose pointing out both native and invasive plants along the way.  She will explain various methods of identification methods observing foliage, bark, flowers, and various other growing characteristics. She will make recommendations on how the invasives can best be eliminated or at least controlled.  Dr. Pyle will suggest alternative native plantings that we could add that would be adaptable to the environment along the trail once the invasives are removed.  

Our town is providing lunch at no cost to attendees.  After lunch, we hope to begin removal of some of the invasive plants.  If you have never walked here, I would describe it as a beautiful little trail, actually an elevated boardwalk, that begins in front of the Scotland Public Library and connects via town land to the fire station.  The trail is definitely worthy of some cleanup and landscaping. Attendees should wear appropriate footwear, as we will be working in the wooded areas alongside the boardwalk.  Prepare for ticks by tucking pants into socks.  Bring a pruner and gloves.  This is a rain or shine event, so hopefully the weather will cooperate!   

 

                                                            Callery Pear in Bloom

                                     Sharp thorn-like growths

                                           The Round Fruit

Callery Pear AKA Pyrus calleryana

This spring, for the first time, I noticed a small attractive tree with showy white flowers growing near the border of a state-owned field across from our house.  It being something new to me, I snapped a picture of it and asked my smart phone for an ID.  The phone readily complied suggesting the tree was a wild Callery pear tree.  In searching for more information, I found first of all that The Id. provided by my phone was correct, and secondly that these trees are yet another invasive plant. 

Here is a tad of history about how they arrived on our shores and how they became invasive should you be interested.  The trees were brought here from China, along with many other plants, during the early 1900's.  It is during this time period that ranching in the Pacific Northwest began to transition to farming. Many trees and plants likely to survive in that climate were transported from not only various parts of the United States, but from other countries as well.  Great emphasis was placed on exploring China for potential imports as the climate in parts of China was similar to that of the Pacific Northwest. It was believed plants from those areas in China would likely survive and thrive here.  Previously, in the Pacific Northwest, orchards had been planted with numerous French pear trees. Sadly, multitudes of these trees were succumbing to a disease called fire blight.  A diseased tree would exhibit branches and leaves that appeared shriveled, looking exactly as though they had been through a fire.  Just in the nick of time plant explorers in China discovered the extremely hardy Callery pear tree.  The trees were so self-preserving they even had spiny thornlike growths along their branches which deterred wildlife from grazing on them.  Grafting the French pear trees to Callery pear rootstalk seemed like the perfect solution for the survival of the diseased French pear trees.  Callery pear seeds were imported from China by the thousands and from them thousands of trees were successfully grown, and varieties of the less hardy pear trees were then grafted to them.  Problem solved?  Well yes and no. The fire blight issue was resolved, but let's fast forward to the year 1952.  This is when John Creech from the USDA happened to observe one of the older remaining Callery pear trees that was being grown as potential rootstalk.  The glossy leaves, the globular form, and tree's showy bloom struck him as very appealing.  Additionally, this particular Callery pear tree did not exhibit the usual sharp thorn like spurs on its branches.  Seeing its potential as a landscape tree, he started several scions, essentially clones, from cuttings of the tree's branches and named the resultant trees Bradford pear trees. The USDA continued to grow more and more of these clones. During the housing boom in the 1960's, the Bradford pear trees were heavily marketed.  After the successful marketing campaign, the trees were found just about everywhere.  Bradford pear trees are not self-fertile.  Even if you plant two Bradford pear trees near each other they are essentially sterile. Therefore, Bradford pear trees could safely be grown as ornamental trees without danger of overpopulating the environment. 

By the 1980's, as the trees matured, problems with branch breakage, sometimes resulting in total tree breakage, began to occur. Since the tree was such a popular ornamental, alternative cultivars were developed, each, on its own, essentially sterile.  This is where the invasive outlaw problem began.  Unfortunately, the several different cultivars of Callery pear trees developed and marketed in the 1980's, though sterile individually, were able to cross pollinate with each other. They could also cross pollinate with the Bradford pear.  In addition, the new cultivars were capable of cross pollination with cultivated orchard varieties of fruit bearing pear trees.  The seeds and resultant trees from cross pollinated ornamental pear trees reverted to the original imported Callery pear trees with all of their wild traits, including the trait of those tough sharp 4" thorn like spines!  The wild Callery pear trees are no longer sterile.  They bear numerous small round fruit each containing several seeds within.  As some of that fruit is consumed by birds, the seeds pass through their digestive tracts and are scattered through the landscape while the birds are on their travels.  Eventually these seeds germinate creating a new colony of wild thorny pear trees also capable of reproducing.  Any fruit not consumed drops close to the original tree and germinates in place beginning the creation of a thicket of these invasive trees.  As if that is not enough, the trees send out lateral roots occasionally sending up shoots forming yet more trees. Dense thickets of these thorny trees can prevent wildlife from passing through and birds from nesting.  Woodland areas infested with these invasive trees become unpassable for human recreational activities as well.

So, how exactly did that tree get in the field across from our house?  I believe the Bosc and Bartlett pear trees growing in our orchard somehow became cross pollinated with a Callery pear tree, either a wild one or somebody's ornamental.  Several years ago, a gang of criminal squirrels harvested our entire crop of perfectly ripened pears for themselves. They are the likely culprits responsible for planting the Callery pear tree I observed in that field, and I fear there will be more!  

You can readily identify a wild Callery pear tree.  Its leaves look glossy and similar in form to that of a regular pear tree.  The wild Callery pear has the numerous sharp woody thorns that grow along its branches.  Another identifying characteristic of either wild or cultivated Callery and Bradford pear trees is the abundant showy white flowers which are said to smell like rotting fish or urine.  The odor attracts flies which are the trees primary pollinators. I have to say I did not notice that odor when I photographed the wild pear in the field for smart phone identification, but I did not get all that close to the tree either. Callery pears are considered invasive in many states including Connecticut.  According the UCONN invasive plant list, Callery pear cultivars will be banned for sale in Connecticut beginning in 2027.  Beware! as of 2025 Bradford pear and Callery pear cultivars are still being sold in Connecticut!!  There are many attractive native alternatives that bear flowers that don't smell like urine or rotting fish! Select one of those instead.