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Invasive “Aliens” Compendium Rick Findlay originally authored this series of articles for the Littleton Conservation Trust newsletter. They appeared in each spring and fall issue from Fall 2005 to Spring 2012 with additional coverage in Fall 2014. The articles have been lightly edited and combined in this single document for ease of access. Japanese Knotweed Fall, 2004 Japanese Knotweed is native to eastern Asia and was introduced to this country in the late 19th century. It is a bamboo-‐like plant growing in stands up to 9’ tall with unlimited potential spread. It needs full sun to thrive. Its seed is not generally viable, but once established has a good chance of a long and flourishing life. Its primary means of reproduction is through underground rhizomes, some as long as sixty feet. Gardeners frequently spread it by moving the roots while trying to eliminate it. It loves a compost pile. Transportation of contaminated soil is often responsible. Although common in New England, it is most threatening to riparian habitat where root fragment dispersal has created expansive populations. Along sections of the Connecticut River it has crowded out native flora and fisherman alike. Littleton should try to eliminate all Japanese Knotweed, but concentrate on the drainages that lead to our brooks and ponds. Stands need to be cut three or four times a year for several years for any real chance of success. Herbicides, such as Roundup, may be helpful but should not be used near water. Yearly monitoring of stands well into the future is important. There is a lot of information on the internet. We urge you to get to know the enemy and join the resistance. Although the State and Federal governments are addressing the problem, we as individuals and neighborhoods have the only real chance of significant control. Burning Bush or Winged Euonymous Spring 2005 Euonymus alatus, commonly known as Burning Bush or Winged Euonymus, is high on everyone’s list of invasive alien plants, yet only the most responsible nurseries have stopped carrying it. It arrived from central Asia more than 150 years ago, and recently has become the darling of residential builders and interstate bridge beautifiers. Burning Bush thrives in full sun where its neon red leaves excite the leaf peeper. It does almost as well in shade. Truly a wonderful plant were it not for its fibrous root mat and its seeds. The root mat excludes all other plant growth, altering natural plant communities, capable of creating a monoculture in the shrub layer. Writing from my own experience, the young plant is not bad. As it gets older and larger, however, it starts to produce seed in prodigious amounts. The birds love it and carry it afar. At first I noticed a seedling here and there. Then one day they were everywhere, sometimes growing thicker than my lawn. I cut them and mowed them but they came back stronger than ever. The venerable specimens at the head of my lawn became cordwood, but did they die? No. Did the seeds stop sprouting? No. It appears that they are viable for an indeterminate period. I bought a new and better weed whacker, and then there’s mulch . . . The real problem is the seeds. My plants (they came with the house) have spread their progeny well beyond my property. In the fall, an embarrassing hue in the landscape intensifies as I approach home. Migrating birds have taken the seed who knows how far. Mitigation methods include pulling and fall or winter cutting, when cut surfaces can be painted with an herbicide (Roundup at 30 -‐35% has been recommended). Oriental Bittersweet Fall 2005 Oriental Bittersweet (Celastrus orbiculatus) is a vine common enough that most of us have tangled with it at one time or another. It may have come into our home as a holiday arrangement (pretty orange berries) and taken over the yard via the compost pile. More likely a bird left a seed under a shrub and the emerging vine soon enveloped the shrub. Bittersweet is an extremely aggressive invader smothering all types of native vegetation much like the Kudzu of our southern states. Well-‐supported vines can reach six inches in diameter and take down full grown shade trees. On the ground, a three-‐foot high tangle can cover a field. It kills by girdling and shading, thus preventing photosynthesis of the plant it is smothering. It was introduced as an ornamental in the 1860’s and has now spread from Maine to North Carolina and Illinois. We will likely never get rid of it in Littleton, but we can manage it by destroying the largest seed baring vines. Since these are the most obvious, especially in autumn, it should be possible. Unfortunately, simply cutting the vine only stimulates regrowth. A number of conservation organizations have suggested that the only way to kill it is by painting the cut end with a concentrated solution of Glyphosate (Roundup), or Tryclopyr (Brush-‐Be-‐Gone). When using herbicides, always follow label instructions and take recommended precautions. Be certain that your chemical is labeled for your site. Visit the New England Wildflower Society web site (www.newfs.org) for additional information and links to other sites. Note that there is a native American Bittersweet (Celastrus scandens) that blooms and fruits at the tips rather than along the stem. Japanese Barberry Spring 2006 Effective January 1, 2006, more than 140 invasive plant species , including Japanese Barberry cultivar ‘Rosy Glow”, are on a list of prohibited plants in Massachusetts. Most cannot be imported or propagated in the state from that date forward. A few of the more popular ornamentals such as Japanese Barberry, Norway Maple, Burning Bush and the shrub Honeysuckles have been given a 6 month importation extension, and propagators have been given 3 years to sell plants they have in production. By 2009, all will be out of commerce. (See the Massachusetts Nursery and Landscape Association web site for additional information: www.mnla.com) These plants are out of commerce, but certainly still with us, thanks to their tenacious nature. Japanese Barberry (Berberis thunbergii) and European Barberry (Berberis vulgaris) are available in an array of colors and sizes. Comely hybrids, such as Crimson Pygmy, Bagatelle, and Helmund Pillar produce thousands of little red drupes that grow up into homely little pricker bushes. Birds spread the seed far and wide and plants can soon dominate the forest understory to the exclusion of native wildflowers and shrubs. Japanese Barberry (mounding with single thorns in the leaf axils) and European Barberry (upright with 3 thorns in the axils) grow throughout Littleton, but fortunately not in the alarming concentrations found in the Berkshires, Connecticut , and southern Maine. We can prevent that from happening here by pulling (with heavy gloves) or grubbing out plants when we see them. Care should be taken to remove all roots because fragments have been known to re-‐sprout. Herbicides, such as Roundup and Brush-‐Be-‐Gone, are effective as foliar sprays or in cut stem applications. Follow the label instructions. Glossy and Common Buckthorn Fall 2006 Glossy and Common Buckthorn are becoming problems throughout Littleton. They were brought to this country in the 18th century as ornamentals. They have naturalized and have now been banned in Massachusetts because of their aggressive nature. We will never get rid of them, but their success at displacing local native vegetation will depend on our efforts to limit their expansion. Courtney Gilbert and TJ Gill, also LHS students, spent Spring, 2006, learning how to identify invasive plants as part of an AP Biology Independent Study. They then conducted an inventory of invasives in Bumblebee Park. Their map and display were in the Library that Summer. The dominant invasive was again Glossy Buckthorn. Art Lazarus and his stewards have been working with their plan to restore Bumblebee Park. For Park neighbors, Glossy Buckthorn will be a growing problem. Buckthorns are easily spotted in the landscape, and their seedlings easily pulled. The dark bark of Glossy Buckthorn is flecked with white. Bark of Common Buckhorn often has a distinctive pewter or lead color. For those looking for more information, the internet is an excellent source of both pictures and control measures. A Google of “Invasive plants” will yield almost 2 million sites. Some of the better ones include: • www.ontariotrees.com/index.php • www.na.fs.fed.us/fhp/invasive_plants/index.shtm • www.nps.gov/plants/alien/index.htm Learning to identify the top ten invasive plants is very easy. Pulling them up when you see them is a noble act. Multiflora Rose Spring 2007 Multiflora Rose is an oriental species with a long history of use as a rootstock for ornamental roses. Over the years it has been promoted as wildlife food and cover, erosion control, highway planting and as ‘a living fence’ to contain cattle. It was so highly thought of that State agencies gave away cuttings to encourage its use. Today we recognize it as a threat to open woods and fields, and have banned its importation and sale in Massachusetts. Nevertheless, with each plant capable of producing half a million seeds and a host of birds anxious to plant and fertilize them, we have a problem that will not go away. My gardening reference Bible puts it this way: “LANDSCAPE VALUE: None in the residential landscape; has received a lot of attention for conservation purposes; makes a good place for the ‘critters’ to hide, yet can be a real nuisance, for the birds deposit the seeds in fence rows and open areas, and soon one has a jungle; use this species with the knowledge that none of your gardening friends in the immediate vicinity will ever speak to you again” (source: Manual of Woody Landscape Plants by Michael A. Dirr). It is hard to find a property in Littleton that does not have at least one Multiflora Rose growing somewhere. Plants can be grubbed out or repeatedly cut back to the ground. It is particularly sensitive to Roundup, and a dilute 1-‐2% foliar spray has been reported effective. Mid-‐June is a good time to spot flowering plants in the landscape. Norway Maple Fall 2007 The Norway Maple has long been a staple for street tree planting throughout the United States and Europe. Unfortunately, today in this country, it is a threat to forests of all sizes thanks to its ability to out-‐compete other trees and suppress native vegetation. This maple’s dense canopy, fibrous surface roots, prodigious seed production, and extended growing season make it a threat to all plant forms (and a lousy lawn tree as well). On a practical level, isolated city or suburban trees are not a threat because seed (or samaras) are spread by wind and don’t travel far. If a tree lies within a few hundred feet of undeveloped land, however, you can count on seedlings eventually finding their way to it. The state of Massachusetts has banned the importation of Norway Maples after 2009, allowing growers to profit from existing stock. Young Norway Maples are hard to distinguish from our Sugar Maple, however a simple test works well during the growing season. If a leaf is pulled from a twig, the petiole where it was attached will exude a milky, latex like substance. The Sugar Maple’s leaf will not. Norway Maples are most easily spotted in the late Autumn landscape when their yellow leaves stand out in the otherwise bare forest . . . a good time to mark them for cordwood. Honeysuckle Spring 2008 It is difficult to stand anywhere in town and not be within sight of a shrub Honeysuckle. In some areas, they have created impenetrable thickets, but more often they team up with invasive Buckthorns, Autumn Olives, and Multi-‐flora Roses to dominate hedgerows, roadsides, abandoned fields, and young forests. There are already enough plants producing enough seed to create an instant nuisance on newly disturbed soil. If landscapes get “out of control,” mitigation efforts are costly and in themselves damaging to habitat. The best way to deal with shrub Honeysuckles is to remove them when you discover them. Spring and Fall are good times for engagement because early leaf-‐
out and late leaf-‐drop make them conspicuous in the otherwise leafless landscape. It is this same trait that helps them out-‐compete our native flora. There are native Honeysuckles in New England, but only in the northern range. If in doubt, you can identify invasive Honeysuckles by their hollow twigs. Pulling small plants requires only good gloves. Mature shrubs can be grubbed out or repeatedly cut. Applying the herbicide, Glyphosate, to cut stems is effective as well. Read the herbicide label carefully for precautions, timing, and concentrations. Autumn Olive Fall 2008 Autumn Olive is a deciduous shrub blessed with silvery leaves, sweet-‐scented flowers, and red fleshy berries. It can grow to 20 feet and establish impenetrable thickets in once open fields. It has been in this country since 1830 but has only recently established itself as the bully that it is. It has been banned from commerce here in Massachusetts, but realistically, it is with us forever. Through our efforts, we can choose to have a little, or a lot of it. Littleton has large ‘groves’ of Autumn Olive on the Cisco site and around the quarry near Spectacle Pond Road. Thanks to several bird species, plants are germinating freely all over the west side of town, and an abandoned lawn there can soon expect to be an olive grove. Autumn Olives should be pulled when young or they will soon require a chain saw. Pulling small plants requires only good gloves. Mature shrubs can be grubbed out or repeatedly cut. Cut stem applications of Glyphosate (Roundup) are effective as well. Read the herbicide label carefully for precautions, timing, and concentrations. Garlic Mustard Spring 2009 Garlic Mustard is a biennial. Its first year is spent as a rosette of green, scalloped leaves. In its second year, it flowers on two to three foot stalks, drops hundreds of small seeds, and then dies. Alas, that is not the end. One plant’s seed will soon commandeer a roadside ditch, and then the land nearby. A weed virtually unknown in Littleton a few years ago, Garlic Mustard has become a major nuisance for residents and land stewards, and a major threat to local wildflowers, insects, and forest ecosystems. As a steward of Conant Park I was surprised to see Garlic Mustard covering a large area just off White Street. I was well familiar with the plant and shocked by its stealth and/or my own inattention. After three years of pulling and Roundup applications, I believe it is gone, but with seed viable for up to five years, I may well be in for another surprise. Once established, control can be achieved by constant pulling for several years, but failure to stop a single plant from going to seed can start the process again. Rise to the challenge! Black Swallow-‐wort Fall 2009 Black Swallow-‐wort is a vining member of the Milkweed family with wind blown seed. It is native to the Mediterranean. Shiny dark green leaves attracted American gardeners as early as the mid-‐eighteenth century. Not long afterwards, botanists were noting the plants ability to move through the landscape. As with so many of the invasive plants now plaguing us, this plant seems to have behaved itself for hundreds of years, only to become very aggressive in recent decades. As a gardener and amateur botanist here in Littleton for over 35 years, I didn’t see this plant until four years ago. A patch off of Route 495, that has since grown, was followed by a plant in my own garden a couple of years later. This year, I found two patches on the Yapp Conservation Land. This plant has the ability to displace even goldenrod, itself an aggressive plant, in old fields. Should you discover this plant on your property, try not to let it go to seed. Pick ripening pods and dispose of them with your garbage. Dig out plants or spray with Roundup Pro after flowering, carefully following the label. The internet is a good source of more pictures and information. Porcelain Berry Spring 2010 Porcelain Berry is a perennial vine related to, and closely resembling, our native grape. Distinguished by its pale, porcelain-‐blue berry, it is not common in Littleton. I have only seen it on the NEFF property. Like Bittersweet, it has the ability to climb over and smother shrubs and trees. It can grow fifteen feet a year and the seeds can remain viable in the soil for many years. Detection and treatment of early invaders is important because of the opportunity to control or even eradicate a species in an area before it becomes established (like Bittersweet). When not in fruit, Porcelain Berry vines can be differentiated from grape vines by stem pith, which is white in the Porcelain Berry, brown in the grape. The bark on a grape vine peels off in strips, where on the Porcelain Berry, it does not. Should you discover this plant on your property, try not to let it go to seed. Pick ripening berries and dispose of them along with your garbage. Dig out plants or cut them close to the ground and paint the stump with a Roundup or Brush-‐Be-‐ Gone concentrate. Carefully follow the herbicide’s label. Mile-‐a-‐Minute Vine Fall 2010 Over the course of the past six years this column has tried to introduce readers to the dozen species that most threaten Littleton in terms of habitat destruction, diminished biodiversity, and landscape aesthetics. There is nothing more beautiful than the New England countryside and nothing sadder than the sight of it being swallowed by 60 foot waves of Bittersweet. Alas, these species are here to stay, and we can only hope to protect our own property and the open space we have invested so much in. Had we known that any one of these plants would cause pain and financial hardship, we surely would have been more vigilant from the start. There is an opportunity to show that vigilance now. Volunteers are working throughout the state in an effort to seek out and destroy a new wave of invasive plants expanding their range north with warming temperatures. Of importance to us is a plant called Mile-‐a-‐Minute Vine (also known as MAM, Polygonum perfoliatum, Devil’s Tail, and Asiatic Tearthumb). It is very aggressive, competing well with Bittersweet in its ability to envelop or cover. A couple of years ago it was thought that there were only two sites in the state. With growing awareness, it has popped up elsewhere, including here in Littleton and neighboring Westford. In September, volunteers from town stuffed garbage bags with the vine in an effort to keep birds from the ripening seed. We will be monitoring the site for the next five or six years to prevent dormant seed from reestablishing the population. MAM is an annual and requires only pulling to keep under control, however, once seed has formed, vines should be pulled, bagged and incinerated. At this time, discovery is of utmost importance. If you come across Mile-‐a-‐Minute, take a photograph, note the location and report it on line at http://massnrc.org/pest or by phone to the MDAR Plant Pest Hotline: 617-‐626-‐1779. The Littleton Conservation Trust is always ready to help. Please call Rick Findlay for assistance: 486-‐8482. Taking Stock Spring 2011 We first brought the issue of invasive plants to the attention of Littleton readers in our Spring 2005 newsletter. Over the next five years, we highlighted a dozen or so of the worst species for our location, including Japanese Knotweed, Oriental Bittersweet, Burning Bush, Buckthorns, Multiflora Rose, Norway Maple, Shrub Honeysuckles, Barberries, Autumn Olive, Garlic Mustard, Black Swallow-‐wort, Porcelain Berry, and Mile-‐a-‐Minute Vine. We have seen a growing concern at all levels of the private and public domain. In summer and early fall 2010, I heard from Girl Scouts here in Littleton, a multi-‐town group in the Adirondacks (www.noknotweed.org), and the Baystate Roads Program, a cooperative effort of the Federal Highway Administration, Massachusetts Department of Transportation and the University of Massachusetts. In 2009, Littleton and the Trust joined the SuAsCo CISMA, a watershed-‐wide group led by the U.S. Fish and Wildlife Service, the National Park Service, Mass Audubon and the New England Wild Flower Society, among others. There is no shortage of concern and ‘resistance’. A tangle of Oriental Bittersweet At the same time, I watched as roadsides and hedgerows throughout our town have slowly succumbed to the stranglehold of Bittersweet and Poison Ivy (native), energized by rising CO2 levels. I also visited homes, out of control and far beyond the energy and means of their owners. On a brighter note, LCT applied its Federal WHIP Grant to clean up a part of Sarah Doublet Forest. My own property, which triggered my mania in the first place, finally got under control. I was able to get back to gardening for fun. I am also very encouraged by a neighborhood project to reclaim town-‐owned land surrounded by Grist Mill Road. What was once a worthy entrance to our town, a view of pond and pasture, has become a tangle of dead and dying trees. There are many obstacles to a full restoration, but people are stepping forward, and I am very hopeful. Ultimately it will be each of us, working alone and together, that save our landscape and ecosystems. Towns nearby have organized ‘Garlic Pulls’, a one day effort each year to prevent flowering Garlic Mustard from going to seed. I have considered ‘Knotweed Razings’, along the lines of ‘barn raisings’, where neighbors helped each other with a task too big for themselves alone. It will require some creative thinking. Eventually the town will have to join the effort, starting by again attempting the control of Poison Ivy. New town costs are scary, but we will eventually have to pay, now or later, and later will be that much more expensive. Weed Control Fall 2011 $50,000 for 'Weed Control'? Out of CPA funds? A recent notice in the Boston Globe that the town of Harvard was voting to use $50,000 of CPA funds for weed control caught my attention. A little research turned up 39 CPA-‐ funded invasive species control projects in towns such as Chelmsford, Sudbury, Lincoln, Concord, and Weston. There are those who might consider it a waste of money, but I am convinced that it is a “pay now or pay later” situation, with costs escalating with time. Delay will ultimately flirt with the tipping point beyond which control is unsustainable financially and the landscape, something from which to flee. At the Annual Meeting of the SUASCO CISMA, the regional group to which the Town Conservation Commission and LCT belong, we were treated to presentations of a number of community projects. One was a WHIP Grant similar to what the Trust is doing at Sarah Doublet Forest, and others were volunteer efforts. The most impressive was an Eagle Scout project designed to control Mile-‐a-‐Minute Vine in Westford. The Scout, Aziz Rangwala, organized nine teams, each with their own leader, to pull the nasty plant throughout the summer and early fall. Volunteers from other towns, including myself, helped to control a very significant infestation. Here in Littleton, five two-‐person teams worked to control a much smaller plot, one of only a few in the state. It is the fact that there are only a few locations statewide that makes early detection and eradication by citizens, such as you, so important. Sightings of Mile-‐a Minute Vine can be reported to Rick Findlay at 978-‐486-‐8482 or to the MDAR Plant Pest Hotline at 617-‐626-‐1779. These projects will need to continue for five or six years until all seed in the soil has germinated. Volunteers are always welcome. Readers can learn about the problem plants in our community by reading this column in previous newsletters available on the Trust’s website, http://littletonconservationtrust.org in the newsletter archives. Additional information will be available at www.cisma_suasco.org as that website is developed, and numerous other sites will respond to an online search for 'Invasive Plants'. Technology and Volunteer Groups to Fight Invasives Spring 2012 The ongoing battle with invasive plants is not going well but reinforcements are coming armed with the latest technology. Smart phones with specific applications (apps) will allow volunteers to identify and map invasive plants and insects, and then track removal efforts. "Outsmart Invasives" is a free app developed by UMass Amherst, Mass DCR and the University of Georgia to enlist citizens in invasive plant monitoring efforts. A visit to their site and a viewing of their creative YouTube video is entertaining and educational. The app helps with identification and streamlines reporting. In recent years there has been interest from the scouting community and school classrooms in organizing a Garlic Mustard Pull similar to what has been done in nearby communities. With the advent of this kind of technology, the time is ripe and anyone interested should contact me. At the same time, our fight with Garlic Mustard is still primarily a homeowner issue and remains the biggest threat to property values short of an oil spill. For a major infestation there is no simple solution, at any cost, and complete removal requires a multiyear commitment. At this time most homebuyers are unaware of the issue, but in time invasive plants will be a part of the home inspection process and a shock to some home sellers. Weed Wrenches (weapons) available on loan!!! Fall 2014 In support of the ongoing battle against invasive plant species, the Littleton Conservation Trust has acquired a number of devices designed to extract unwanted shrubs, vines and small trees from the ground. These “weed wrenches” were purchased for use by our small army of volunteers, but the Trust also invites homeowners to borrow them for any private invasive vendettas. We have long known that long-‐term success preserving our wonderful landscapes ultimately requires an educated and active private sector. Anyone interested in a ‘loaner’ and demonstration can contact Andrew Sammarco or Rick Findlay. We are also available to help homeowners identify invasive species on their own properties. Autumn and spring are good times for spotting species such as Burning Bush, Glossy Buckthorn, Shrub Honeysuckles and Bittersweet seedlings. Unique coloration on plants that typically hold their leaves later, and frequently emerge earlier, than natives make them more conspicuous. These are excellent times to attack with a Weed Wrench.