Posts Tagged wetland invasive species
I know I’m not the only person out there who had a rough summer. Trials and hiccups aplenty came at me for many months. I could not wait for the autumnal equinox in September, thinking the season change would bring relief. Instead, it brought the worst drought experienced by my five acres in twenty or so years. Unrelenting heat and the absence of rain left the creek bordering our property completely dry, except for deeper pools, where great blue herons happily devoured fish trapped therein.
The contrast between this September and last year’s relentless hurricane rain flooding could not have been more stark. Climate change smacked me and my land hard two years running.
Substantial Damage to Our Protected North Slope
In June, the antique septic field associated with our 50-year-old house was replaced with a new one. The devastation to my deer-fence-enclosed north acre full of native rhododendrons, magnolias, viburnums, vacciniums, and shade-loving choice wildflowers threw me into a tailspin of depression. Wonder Spouse and I planted these beauties as tiny things – all we could afford – 20-30 years ago. As previous posts here can attest, they have flourished, blooming more wonderfully every year.
Even though we marked off our botanical treasures with flagging tape, even though Wonder Spouse took off two days of work to oversee the trenching, that once-beautiful area was significantly damaged after he returned to his office and I was away at an appointment. On top of that, we were forced to remove a mature water oak before the work began, because it had early signs of heart rot. We couldn’t risk having the tree topple and rip up the newly installed septic field.
That enclosed acre is on a slope, which is great for siting rhododendrons, but when earth is scraped, then compacted, erosion from rare-but-heavy rains quickly created myriad little gullies. Soil washed from hilltop to hill bottom, depositing more than an inch of silty mud. I am not ashamed to admit that I cried for two weeks, mourning the loss of trees and shrubs ripped away by machines, the much-missed shade of the venerable water oak, and the wildflowers obliterated by careless men oblivious to the vibrant beauty before them.
Eradication of Surrounding Forest by Bulldozers
Most of the areas near us that were forest thirty years ago have either already been erased and replaced with monotonous subdivisions, or that devastation is ongoing as I type. Every day, more displaced wildlife from those areas arrives on our land, as evidenced by what our wildlife camera beside the creek captures weekly. A considerable beaver population has been forced on top of the wetland adjacent to our property. Up to now, they had been content to maintain their growing pond on our neighbor’s land, but yet another new subdivision (housing prices starting in the mid-$600s!) has pushed them to expand their dam so that our bottomland is rapidly going under water.
Ongoing Radical Transformation of Our Two-Acre Floodplain/Wetland
That was the third strike against our floodplain this year. The first came in April when deadly Emerald Ash Borers were confirmed to be invading the 37 mature (70+ feet tall) green ash trees that dominate the canopy in that area. The second came in late summer when a plant I had never seen before that had spread over most of the floodplain finally bloomed and I was able to identify it as a non-native invasive plant from Asia that, I’m told, has already overgrown all the floodplains of the NC coast and is now moving rapidly into my Piedmont region. It is called Marsh Dayflower (Murdannia keisak), and it is a nightmare. I never thought I’d type this sentence, but Marsh Dayflower dominance makes me long for the days when Japanese stiltgrass (Microstegium vimineum) was my biggest problem. Strike three – the beavers – are actually using Marsh Dayflower to their advantage. They rip it up, mix it with mud, and pack it between the logs they cut down to build their dams, making the dams even more impervious to the force of moving water than before. This is a mutually beneficial relationship, because when stem segments of Marsh Dayflower are broken, as for example, when ripped up by beavers, every segment grows roots, thereby multiplying this invader even faster.
After two years of epic landscape destruction/alteration, any illusions I ever had about being able to control what happens on my land are entirely dispelled. I always understood that, at best, I was a design collaborator as I tried to work with the native ecosystems on our land. However, the last two years have convinced me that the native ecosystems are almost as ineffectual as I am at managing changes we were never designed to handle. Wholesale eradication of habitats by bulldozers in combination with a growing number of non-native invasive species of animals, plants, fungi, and bacteria and the overwhelming introduction of herbicides and pesticides killing wildlife by the millions if not billions, are completely disrupting the natural processes native ecosystems evolved to handle change. We can’t keep up. Species are dying at record rates. It is enough to make a lifelong gardener want to surrender – almost.
A month or so ago, I attended a lecture by a pair of enthusiastic master gardeners from an adjacent county. They described how they transformed their half-acre home lot into a flowering paradise, bragging that 50% of the plants they have added are native to the southeastern US. To justify planting 50% non-native plants, they quoted an “expert” gardener who states that “just because a plant is native, that does not make it better… Choose the right plant for the spot, no matter its origin.” In an exercise of enormous self-control, I did not argue with them. It was their talk, their intentions were good, and it was not the appropriate setting to object.
But I do object, and the last two years on my land are ample reason why. In North Carolina, master gardeners are trained by employees of land grant universities, mostly North Carolina State University. These are good folks with good intentions, but they serve the agriculture and horticulture businesses in the state. Their top goal is to help these businesses be successful. One way to do that is to help the horticulture industry sell plants. Pretty non-native ornamental plants not eaten by native wildlife because they don’t recognize them as food make a lot of money for the horticulture industry.
[NOTE: One of the finest agricultural extension agents I know has pointed out to me that when they work with home gardeners, their goal is only to make those home owners successful gardeners, not help the horticulture business sell plants, regardless of origin. I did not mean to imply otherwise; I think that may, however, often be an unintended consequence of not providing an ecological framework for gardeners. As I responded to her, when agents keep pushing old thinking (right plant for right place regardless of origin) about how to approach home landscapes, they are not helping to save native ecosystems. In my conversations with agents and master gardeners from other counties, it is clear that most don’t understand the role of native plants in ecosystems. They categorize natives as “thugs,” for example, if they multiply assertively, without understanding the ecological role of such plants in nature. In my opinion, such non-contextualized statements do more harm than good. ]
Fifty years ago, this may not have been a terrible thing. But oh how much our world has changed here in North Carolina in the last 50 years. Expanses of forests and fields that once provided buffers and havens for native wildlife and plants are nearly gone in much of the state. Wildlife species are disappearing. Pollinators are dying from poisons; the birds that eat them are also disappearing. Humans need those ecosystems to moderate air pollution, control erosion, pollinate and protect our crops, etc.
We also have hard data from scientists now that demonstrate that landscapes must contain 70% native plant species to adequately feed nests of baby songbirds. That’s seventy percent, not fifty.
This is not a Drill!
We need every patch of native plants we can introduce on public and private lands not covered by concrete and buildings. We no longer can afford the luxury of filling our landscapes with non-native plants that provide no ecosystem services. We can no longer indulge in 50-year-old thinking. This is not a drill, people. Native plants are our only hope of saving what’s left of our native ecosystems, especially the rapidly disappearing wildlife species.
Only a radical shift in the way we think about our public and private landscapes will serve the future now. It is past time to discard old thinking and focus on saving as much as we can. I pray every day it is not already too late. And I’m not just sitting at my computer wringing my hands in frustration. After my initial depression dissipated, I got busy. With the help of Wonder Spouse and my amazing garden helper, Beth, we have planted many new species and introduced existing natives to new sites opened up by the uninvited changes to our land. Our land had a tough summer and a hard fall, but I’m determined to do everything within my power to make next spring a much better season. I’ll describe some of what we’ve been doing in another post I hope to write soon.
In the meantime, if you care about the future of our planet, especially the rapidly urbanizing area of the southeastern US where I and most of my readers live, if you have children and/or grandchildren, I beg you to empty your brain of the old ways of tending your landscape and join me in the radical changes required to salvage as much as we can of our native ecosystems. It will be different, but more beautiful than ever. Most important, it just might help us all hold on to a healthy, balanced, vibrant world – a fitting legacy for those who follow us.
If you’ve read this blog much, you’ve read about my feelings regarding invasive exotic species. These plants/animals/diseases are not native to the region, which means they have no natural predators. They move in, spread aggressively, and permanently alter the composition and health of our native forests.
The problem is world-wide. Ecologists everywhere consider invasive species to be the second biggest threat to the remaining biodiversity on our planet. Only outright habitat destruction due to urbanization poses a greater threat to the health of our ecosystems.
Of the alien plant invaders I hate the most on my five acres of North Carolina piedmont, I think the Most Evil prize must go to Japanese Stiltgrass (Microstegium vimineum). This invading grass has transformed creeks and wetlands throughout my region into big ugly messes, and the wildflowers and ferns that once flourished there are disappearing rapidly.
Number Two on my alien invader hate list is Japanese Honeysuckle (Lonicera japonica). Except during the coldest of winters, this evil vine remains green all year. Like Chinese Wisteria, Japanese Honeysuckle spreads from tree to tree in our forests, creating a dense tangle of vegetation that impairs the health of trees and provides access highways for predators of our native birds attempting to nest in the trees.
A lot of folks don’t realize that English Ivy is also invading our native forests. Like Japanese Honeysuckle, English Ivy produces berries beloved by birds. They spread the seeds through our forests, and the evergreen ivy starts its takeover. The weight of these non-native vines on our native trees causes them to be more easily pulled down by strong winds and ice storms. And from a purely aesthetic point of view, vines strangling forests are quite ugly.
My yard is also plagued by one of the invading species of Elaeagnus. More of a problem in piedmont uplands than floodplains, I’m finding it all over my yard now, thanks to bird-aided seed deposition.
Much scarier to me are invading evergreen privet shrubs on my floodplain. I see near-solid coverage of this shrub in wet woodlands throughout my region. They outcompete every native plant on the forest floor.
The newest invader on my “I hate it!” list is Asiatic Hawksbeard (Youngia japonica). This astonishingly aggressive low-growing plant is outcompeting even the crabgrass in my lawn! Wonder Spouse is planning an attack with a propane-powered weeder that burns the aggressors into cinders. I don’t want to think about what happens if that plan doesn’t work.
Under the “misery loves company” heading, I’m not alone in my battle against invading exotic species. Every government agency charged with protecting our native wild lands and animals is involved in this fight. Anyone caring for a park, farming, growing timber, or any other related activity is battling invasive species perpetually.
If you live in North Carolina and you have the time and discretionary funds to do so, you might want to attend the North Carolina Invasive Plant Council’s (NCICP) upcoming meeting on Feb. 11-12. They hold the meetings in different parts of the state each year. This year, the meeting is in Asheboro, NC at the NC Zoo. This year’s presentation topics include:
- Invasive plant control in Mecklenburg County parks
- Monitoring and mapping invasive insects and pathogens
- Weed bio-control within a regulatory agency
- Birds and invasive plant dispersal
- Invasive plant challenges facing the Uwharries
- Invasive aquatic vegetation and arteriovenous malformation disease
- Invasive plants knocking at our door
- Weed identification workshop
A field trip on the second afternoon will feature the NC Zoo’s greenhouse and composting operations, as well as demonstrations of how they handle invasive species on their grounds.
I’ve been to a number of these meetings, and I always learn much. For example, it was at one of these meetings that I learned about the Weed Wrench, still Wonder Spouse’s favorite weed eradication weapon.
I’m planning to attend this year, and I’ll report the highlights here. If you live in another southeastern state, consider contacting and joining that state’s chapter of the Southeast Exotic Pest Plant Council. I checked the links to each state, and it looks like the Alabama, Florida, and North Carolina chapters are the most active, holding annual meetings. If you live in Georgia, Kentucky, Mississippi, or South Carolina, I would encourage you to contact those chapters through the above link and ask them why their site is inactive. I can promise you it is not because they aren’t fighting invasive alien species in those states too.
If we stand any chance at all of preserving healthy native ecosystems in our parks, national forests, not to mention our own back yards, we all need to know as much as we can about invasive alien species. Forget about invaders from outer space. The invaders we need to worry about are already here.
2014 is the Year of the Lepidoptera!
To end on a happier note, I thought I’d let my fellow North Carolinians know that our state park system has decided to highlight our native butterflies and moths this year. All of our NC parks will be offering walks and family-focused events throughout the year that will educate folks about these important insects. To find a list of events near you, go here.
I’m reasonably certain that’s a Spring Beauty (Claytonia virginica). This early-blooming spring ephemeral wildflower usually starts blooming just a day or two before the American trout-lilies in a moist woodland at the NC Botanical Garden in Chapel Hill. I’ve always thought them to be exquisitely delicate and lovely, and they were on my “Add Someday” list for our five acres of Piedmont chaos. No longer.
Yesterday, Wonder Spouse and I stumbled across two tiny blooming specimens in the middle of our currently moist floodplain. We haven’t mowed there yet, because we’re still picking up fallen limbs from winter storms, which is probably why it managed to push out flowers in time for us to notice. The Spring Beauties at the NC Botanical Garden grow in what becomes deep shade as the floodplain canopy trees above them leaf out. Our volunteers are in a sunnier locale, near a large pine, perhaps enough to give them afternoon summer shade. From this difference, I conclude that Spring Beauties require moisture more than shade.
Our volunteers likely found their way via floodwaters from our little creek, which is only about ten feet from their growing site, in an area that overflows whenever the creek waters escape their banks. We could not be happier to have this native join us: another native to love.
Wonder Spouse and I spent several hours wandering the floodplain/wetland habitats of our yard yesterday, because this is the time of year when their health is demonstrated by the ecological diversity of the beautiful native plants that thrive in the muck. Indeed, there is much to love in a healthy native wetland. There’s also much to worry about: invaders. Non-native, alien species remain the number two threat to healthy native environments world-wide (after outright destruction), and in my yard, we battle invaders constantly.
From Beauties to Bullies
Some battles are nearly hopeless. Japanese Honeysuckle and Japanese Stiltgrass are so aggressively pervasive in our North Carolina woodlands and backyards that the best most of us can do is to try to keep them out of selected areas — a favorite flowerbed perhaps, or a beloved tree, in the case of Japanese Honeysuckle.
Battles Still Worth Fighting
In my wetland/floodplain areas, the invader we are still fighting — so far, successfully <knock wood> is Chinese privet. This evergreen, common hedge shrub of older homes produces blue-purple berries that birds adore. They distribute seeds everywhere, but the privets are most dangerous to floodplain/wetland environments. In some areas in eastern North Carolina, the understory composition of vast acres of wetlands has been completely overtaken by invading privet. Because these non-natives are evergreen, they outcompete wildflowers, shrubs, and tree seedlings for light and other resources. Eastern North Carolina wetlands are becoming biological deserts, consisting of nothing but privet beneath canopy trees. When those trees die, no seedling trees will replace them, because they can’t compete successfully with privet. Eventually, our eastern wetland landscape will consist of miles and miles of nothing but privet.
Plant invaders are overlooked by most folks, because their progress is slower than, say, invading Emerald Ash Borers or Sudden Oak Death. To the untrained eye, green is green. But native animals and plants know how critical the differences are. If you love your southeastern Piedmont landscape, you should know too.
Whenever Wonder Spouse and I walk around our yard, we keep a sharp eye out for Chinese privets (Ligustrum sinense). Seedlings appear constantly, typically beneath trees, where birds deposit the seeds after feasting on privet fruits elsewhere. Yesterday, we spotted several larger shrubs that we had somehow overlooked previously. Greens blend together, and in crowded thicket areas (left for animal nesting habitat), a privet sometimes escapes our notice — for a while. I am especially vigilant in my hunt for this species in my wetland and along the edges of my creek. These areas are most vulnerable to this devastating invader.
While hunting privet yesterday, I was disturbed to discover that some of the Autumn Olives (Elaeagnus umbellata) invading the top of our hill have made it to the floodplain and wetlands. This pernicious invader has taken over many acres of upland environments, such as ridge tops, in my part of the southeastern Piedmont. This species and its close cousins (E. angustifolia and E. pungens) are all non-native shrub species. All are very bad news for the local environment, despite the berries that birds eat with gusto.
Wonder Spouse grabbed his trusty Weed Wrench and went to work on the invading Elaeagnus shrubs, pulling out long-rooted invaders from mucky ground, accompanied by a rather satisfying sucking sound.
Note the flowers just opening on this one:
This was a larger one that put up considerable resistance before Wonder Spouse prevailed:
A New Enemy
And, there’s more bad news for my little patch of Piedmont: Asiatic Hawksbeard (Youngia japonica). This relatively recent annual invader was introduced by the nursery trade. It was probably inevitable, given the number of plants from nurseries that I’ve added over the decades, that this horrifyingly aggressive invader would appear on our property.
To the casual eye, the basal rosette of jagged leaves of Youngia looks quite like that of a Dandelion. But if you look a little more closely, the dangerous differences become evident. It sends up clusters of small yellow flowers on bloom stalks. Dandelions only produce one, much larger yellow flower per stalk. Seeds of Asiatic Hawksbeard look somewhat like those of a Dandelion; they are both attached to white tufts that allow them to float far on breezes. But Hawskbeard seed tufts, like its flowers, are much smaller — and uglier — than those of Dandelions.
I know you’re thinking this is just one more lawn weed, right? Not really. Unlike our common non-native weeds — Dandelion, Henbit, Chickweed, Lambs Quarters — Asiatic Hawksbeard spreads much, much more aggressively. Its basal rosettes are dangerously easy to overlook, and now the experts tell me that they are moving into our dwindling natural areas. In these diminishing patches of native forest, Asiastic Hawksbeard is joining Japanese Stiltgrass, Japanese Honeysuckle, and larger invaders in displacing native wildflowers and other small native plants. Every new invading plant means more competition for food, light, and water for our natives. With no natural predators to slow them down here, their eventual takeover seems a near certainty.
Asiatic Hawksbeard has a taproot similar to that of a Dandelion, and if you don’t get it all when you pull it, the plant will regenerate. Also, you can’t just toss pulled Hawksbeards onto your compost pile. Flowers and even nearly-open flower buds finish their cycle and release seeds into the environment even after they’re pulled. Knowing this, I spent many, many hours last year carefully digging out this new invader from my yard wherever I found it. Every plant went immediately into a trash bag, which I tied and left in the hot sun to fry before adding it to my trash can. Despite my efforts, the Youngia is much more pervasive now that it was last year. And I’m seeing it in all parts of my yard now, whereas, last year, it was confined to only certain areas. The basal rosettes have a distinctive yellow cast, and the leaves are slightly fuzzy. I’ve become quite adept at spotting them. Next winter, whenever we spot one, Wonder Spouse and I are planning to resort to treating them with Round-up. Wonder Spouse and I are ridiculously outnumbered, and this is a war we don’t want to lose.
Reasons to Keep Fighting
And there is so very much to lose. On this Earth Day, let me leave you with a few positive images from our still-healthy wetland, where the wildflowers and other plants are wakening to warming weather with enthusiasm for another growing season.
On this Earth Day — and every day — I will continue to love the diverse and beautiful native species that bless my property. And I will battle non-native invaders as long as I can breathe. Clean water and air can’t exist without the help of healthy native environments — especially wetlands. Do your part today and every day by eradicating invaders in your yard. To learn more about invaders in Southeastern North America, start here.
If you live in the Southeastern United States, you know this shrub even if you don’t think you do. When I was a child in the 1960s, it was the go-to landscaping choice for quick, easy hedges — evergreen, amenable to severe trimming, and impervious to predators and diseases.
Some people claim to enjoy the fragrance of the white clusters of flowers. Frankly, I’ve always thought they stink — and they make me sneeze like I’ve inhaled a snootful of pepper. I hated them even before I knew what they do to our native forests.
Those white clusters of flowers produce big clusters of purple fruits that birds find irresistible. The berries are this invader’s secret weapon. The birds unwittingly spread Ligustrum seeds everywhere, and this shade-tolerant non-native species quickly grows to enormous size, multiplying its numbers as it outcompetes our native forest understory species.
How bad is the problem? Chinese Privet (Ligustrum sinense) is especially aggressive in our wetlands. A wooded creek near a shopping mall I pass often is completely overgrown with Chinese Privet. In winter, the evergreen invaders are especially visible. They outcompete native wildflowers, ferns, and smaller shrubs and trees for light and nutrients, because their evergreen leaves are working year-round. The natives never see the light of day after these bullies move in.
In North Carolina’s Coastal Plain region, many thousands of acres of swamp forest are now dominated by an understory of privet. Biologists note the quantum drop in species diversity — plant and animal — in areas where Ligustrum rules — a biological desert compared to the days before this invader took over. Nothing eats the leaves, and few natives plants can survive where it dominates.
Because my yard is adjacent to a creek and wetlands, I am constantly on the lookout for this invader. I am determined that my wetland will not look like the one near the shopping mall a few miles from my house. Winter is the best time to spot them in the landscape. When a glint of shiny green catches my eye in February, I know it’s either a holly or a privet.
I can pull small privets out of the ground roots and all in moist soil. Bigger specimens (yes, they occasionally manage to hide from me on my five acres) require Wonder Spouse and his mighty Weed Wrench. Don’t even think about cutting them off at the ground; they come right back, sprouting into even bushier specimens than the originals.
I hate them because of what they are doing to the health and biodiversity of my native woodlands. I hate them because they smell bad. I hate them because they are ugly. I hate them!
Plant nurseries still sell privets today. A fancy variegated form is often touted as an elegant landscape addition. Don’t be fooled. There is no such thing as a noninvasive privet. None is native to North America. Infinitely better native hedge shrub options are available. So, please, just say no to Ligustrum, and do your best to eradicate any loitering invaders in your yard.
For more information on this malicious invader, try here.
And if you live anywhere near the North Carolina Botanical Garden in Chapel Hill, NC, you’ll want to stop by beginning on February 25 to see:
“Plant This, Not That—Alternatives to Invasives,” an educational exhibit at the North Carolina Botanical Garden, opens on Saturday, February 25. The public is invited to attend an opening celebration in the gardens’ Education Center at 1 pm. Associate Director for Natural Areas and Conservation Programs Dr. Johnny Randall opens the event with a short program about invasive plants. The presentation will be followed by a reception, during which six artists who created the exhibit will be on hand to discuss their work. The event is free, though an RSVP is encouraged: call 919-962-0522.
“Plant This, Not That” consists of a series of panels discussing invasive plant issues and showing examples of ornamental native plants that can be used instead of invasives in gardens and landscapes. The artists who created the accompanying illustrations are graduates of the Botanical Garden’s Certificate in Botanical Illustration Program: Irena Brubacker, Betsy Lowry Donovan, Glenda Parker Jones, Joanne Phillips Lott, Julia Shields and M.P. Wilson. Their original paintings will be on display during the reception.
The event launches National Invasive Species Awareness Week, February 26 – March 3, the purpose of which is to bring attention to the impacts, prevention, and management of invasive species and to organizations who are working toward healthy, biodiverse ecosystems.
The North Carolina Botanical Garden is located off Fordham Boulevard at Old Mason Farm Road in Chapel Hill. A unit of The University of North Carolina, it has been a leader in native plant conservation and education in the southeastern United States for more than 40 years. The Botanical Garden is open 7 days a week and admission is free.
Minor News Flash:
On the right side of my blog page, you’ll see a new addition — an image that links to the Nature Blog Network. I’m proud to say my blog is now a member of this group, where you will find fascinating nature-related blogs from writers all over the world. Click on the link and check out this site; I think you’ll like what you find.
What’s the old saying? Insanity is repeating the same act over and over and expecting different results? Or is that stupidity? Either way, on my five acres of North Carolina Piedmont, my greatest exercise in futility is probably attempting to remove/control Japanese Stiltgrass (Microstegium vimineum). Oh, how I despise this invasive exotic plant species. Let me count the ways.
1. It is ugly and covers everything. As you can see from the above photo, it grows tall and droops over everything, living and inanimate. Even when this annual grass dies with the frost, its straw-like dead remnants bury my landscape in destructive brown yuck. That’s a little pond that fluctuates with the level of the perched water table on my floodplain. I’ve surrounded it with myriad well-adapted wildflowers and native shrubs. But you’d never know it by that photo. It’s one of the areas that I didn’t weed this year. Now my pond environment pays the price.
2. It creates rodent habitat that thwarts predators. As these evil invaders create grassy hummocks over logs, shrubs, and small trees, they create excellent cover for field rats, deer mice, and voles. It’s a tunnel-filled grass metropolis in there. You’d think a rodent population boom would benefit my native predators, especially the Barred Owls and Red-Shouldered Hawks. Alas, no. The grass is so thick and covers so much territory that the rodents can largely conduct their business without ever coming into the open and risking capture.
3. It destroys/alters native plant communities. That’s the edge of my property on the floodplain in the above photo. The green area is where we stop mowing (we mow to reduce tick and snake issues). The hummocks of straw-like material are mounds of Japanese Stiltgrass, which are growing on an area that we used to mow before we figured out it wasn’t technically our land. Behind the Stiltgrass, you can see native floodplain vegetation still trying to fight the onslaught of the invader. It was there undisturbed before the Microstegium took hold. If our floods ever return, that vegetation will likely be overwhelmed.
That’s how the Microstegium got to our property — via floodwaters. Back in the pre-drought decades (how I miss them), our creek usually flooded spectacularly 5-8 times a year. As more and more developments sprouted up nearby, removing forest cover, Japanese Stiltgrass appeared in those developments (probably from seeds off bulldozers and other heavy equipment). This annual produces a lot of seeds, and one of their favorite modes of transport is water. Rainwater runoff carried seeds from those developments into my creek, where floods deposited them on my floodplain.
4. It has killed almost all the wildflowers and ferns that grew along my creek 15 years ago. As you can see in the above photo, the nasty stuff overwhelms everything. Delicate ferns and wildflowers don’t stand a chance.
5. Every object I introduce into my garden is a potential Microstegium support, even though that is never my intention. In the above photo, Japanese Stiltgrass climbs the deer fencing on my north side. I can’t mow right up against the fence because of the way it’s installed. Weedeaters don’t work there either. Hand-pulling is the only option. That’s back-breaking, knee-creaking work. And if you don’t do it before the grass sets seed in mid-summer, what you pull returns a hundred-fold anyway. Did I mention something about an exercise in futility?
6. It wastes enormous amounts of time that Wonder Spouse and I could be using for other things. That mountain is the result of last week’s clean-up of our deer-fence-enclosed north side. It’s about eight feet high and twelve feet wide, and is a mix of fallen branches, leaves, and Japanese Stiltgrass. In areas of our yard where the grass hasn’t invaded, we rake up the leaves, shred them, and use them for vegetable garden mulch. But the leaves in that pile were too heavily tangled with the Stiltgrass to recover. A close-up of the pile demonstrates the problem:
If there’s any good news there, it’s that Mount Brushmore is excellent winter habitat for a variety of birds, raccoons, and possums. Air pockets created by piled branches are covered by the thick mass of grass and leaves, creating a thatched roof of sorts that repels rain and insulates against cold.
7-1000. Multiply the above reasons by the number of seeds one plant produces in a season. That’s right. One plant can produce up to 1000 seeds. Contemplating the math is not advised for gardeners with high blood pressure.
When I roamed North Carolina Piedmont woodlands and stream sides as a child and young adult, Japanese Stiltgrass was nowhere to be seen. This invader has transformed/destroyed Piedmont wetlands in just a few short decades.
The deer won’t eat it under any circumstances, but they do enjoy sleeping among the hummocks in winter — instant straw mattresses. I wouldn’t dream of trying to control it with herbicides — not on a wetland, and not with struggling native grasses still present.
One faint hope may be appearing. In Virginia, a fungus has been found to be infecting colonies of Microstegium. The grass seems to be severely impacted by this fungus, and scientists are studying it to determine its origin and whether it can be safely introduced elsewhere to control infestations of Microstegium. All my fingers and toes are crossed on that one. I’ll keep you posted.
Meanwhile, I’ll continue to spend my winters raking dead Japanese Stiltgrass off of plants and structures in the hopes that next growing season I’ll be able to pull the nasty stuff before it sets seed. Oh, did I mention that seeds remain viable in the soil for many years? Yes, sometimes I do wonder why I try to garden at all.
Recognize this flower? Most southerners know it well. Magnolia grandiflora — Southern Magnolia or Bull Magnolia to her friends — is a familiar symbol of the South. Technically, it wasn’t originally native to the southeastern piedmont. The species originated in coastal swamps and bay forests from NC to Mississippi. But such a beauty was, of course, cultivated by botanists and made available to those of us who dwell further inland. Until recently, all you could find were plants that would eventually become 60-foot evergreen dominatrixes of the landscape. Now, numerous cultivars are available that only grow to twenty-five feet or so — a much better fit for the postage stamp lots of many suburban neighborhoods.
See all the honeybees cavorting on the petals? Southern Magnolia flowers are known for their potent perfume, and the nectar is clearly irresistible to pollinators. When you multiply the power of that perfume by the hundreds of flowers adorning a mature 60-foot specimen, you have a tree that’ll smack you in the face a hundred yards away as the scent hangs in humid late May/early June air. The fragrance always seems extra potent on warm nights, because the winds are usually still, so the tree is able to surround itself with an invisible wall of perfume.
How I came to appreciate this native
For many years, I did not appreciate this tree’s assets. I’m allergic to the fragrance of the flowers. Being next to a mature magnolia in bloom sends my nose into fits of sneezing followed by congestion. And I associated it with southern plantation aristocracy. I grew up with the descendants of those folks, and well, let’s just say I wasn’t one of them and leave it at that.
But when we moved to our current home, a large tree was already here, close to the entry. It’s about 40 feet tall now, and I’m pretty sure it was just a seedling that the previous owner planted. He was not a plant cultivar kind of guy. We decided to live with it, because it was quite a specimen, and the shade it offered on the hot western side of the house was very welcome on summer afternoons. We limbed it up so that I could plant shade-tolerant beauties beneath it, and a wooden bench offers a shady respite — a favorite napping spot for cats.
A wildlife bonanza
But it was only after living with this tree for a few seasons that I began to appreciate its real beauty. In late summer/early fall, the fat “cones” begin to extrude bright red seeds that dangle on a filament, so that the seeds look like ornaments hanging on a Christmas tree. These fleshy carmine fruits must be quite tasty and nutritious, because almost every creature that lives nearby descends on my magnolia when the cones open. It sounds like a raucous party from sunrise to sunset. Woodpeckers — red-bellied, pileated, hairy, and downy — all demonstrate their acrobatic skills as they maneuver their way in to grab a seed, cussing in woodpeckerese the entire time, of course. Gangs of robins battle the woodpeckers, while polite and colorful warblers dash in and grab a fruit when they see an opening. The squirrels come too, of course. They just bite off entire cones and carry them down to the bench, where they devour seeds and cone, leaving piles of magnolia debris behind. And even two weeks ago, long after the cones had shriveled up and many had fallen to the ground, I discovered a flock of cedar waxwings fluttering and muttering high in the tree as they meticulously examined every undropped cone, extracting seeds that had never been extruded.
An emerging issue: the invasive potential of this species in the piedmont
A down side to the attractive fruit of this tree is beginning to emerge. Birds eat the fruits, fly to adjacent forests, and “deposit” their seeds on the forest floor, where the seed often germinates. When this happens in a favorable location in the southeastern piedmont, seedlings can be quite numerous. Because this species originated in swampy coastal forests, it likes our river and wetland forests. And because it is evergreen, it can outcompete and even eventually dominate the native forests of these areas. My field botanist friends tell me that there are patches of local river forests in my area that have become solid magnolia forests at the expense of the natives. That includes all the little wildflowers — spring ephemerals, they’re called — that bloom and die back before the deciduous canopy closes over them every spring. But now the magnolias are blocking out their light, and the wildflowers are disappearing.
The invasiveness of this species compared to the scourges of piedmont floodplains — Chinese and Japanese privets — is not as severe, not even close. But it is a growing concern among ecologists who monitor our remaining forests.
I do spot bird-planted seedlings in my yard and, occasionally, in the nearby woods. They pull up fairly easily. For now, I’ve decided to leave my Southern Magnolia alone. So much wildlife relies on it for food, and it’s so much fun to watch them collect it that I just can’t talk myself into cutting it down. At least not yet. As more of my woody wildlife food source plants mature and become significantly productive, I’ll revisit my decision.
Many other native magnolia options
Meanwhile, I have developed a great fondness for other members of the Magnolia genus, especially the big-leaved deciduous species native to the southeastern piedmont. I’ve planted specimens of most of them on the north side of my yard, where they are protected by a high canopy of tulip poplars, sweet gums, water oaks, and river birches. I’ll tell you all about these other trees another time.
And for now, the Southern Magnolia up front will continue to perfume and feed the neighborhood.