Posts Tagged Japanese Stiltgrass
A good friend of mine and her significant other recently purchased and moved into a lovely new home in an adjacent county. They invited me out earlier this week to help them understand what’s growing on their 3-acre patch of Piedmont. I confess, I was a bit envious.
Their home backs onto state park land that protects a scenic river. This land has been covered in Piedmont forest for probably about 100 years now. Most likely before that it was farms and forests, and the forests were certainly regularly logged. That’s pretty much the story of land use for all of the southeastern Piedmont.
Unlike my home, which is on an increasingly busy road (a country by-way when we first moved here), theirs is quite a ways from the nearest main thoroughfare, accessed via a maze of well-established roads filled with nothing but mostly older houses. Frequent speed bumps likely discourage any non-residents from using these roads.
The result? My friend’s new home environment is noticeably quieter than mine. And the vegetation growing on her land and the adjoining protected forest made me long for my childhood days, when all the forests around here looked like that one — mostly anyway.
Her home sits atop a Piedmont ridge. Steep slopes on two sides fall down toward intermittent drainage ways that feed the river below. Large white oaks dominate the landscape; this year’s crop of acorns littered the ground. Mixed among the oaks were tulip poplars, red maples, sweet gums, sourwoods, dogwoods, redbuds, elms, viburnums, and a few mature loblolly pines — in short, all the native species I expect in such an environment.
But in addition to this mix of obviously healthy native plants, what struck me most was what wasn’t there: invasive non-native plants. I only saw two species, and both are likely still controllable if my friends take aggressive action immediately: Japanese Stiltgrass, and Privet.
Just for comparison, in my five-acre yard, I’m fighting those two species and:
We started battling a new invader this year: Oriental Bittersweet. As is true of most of our most pernicious invaders, this non-native vine was planted in the southeastern US for the ornamental value of its abundant, colorful berries. Alas, these berries are beloved by birds. They have “deposited” the seeds all over our southeastern forests. I was horrified when I visited the North Carolina mountains a year or so ago and discovered this invasive vine was snarling vast acreages of once lovely mountain forest.
This evil vine established a beachhead on my property beneath a native dogwood adjacent to my busy road. This mature dogwood produces abundant crimson berries every autumn, and I am certain that birds dining on the dogwood berries excreted the Oriental Bittersweet seeds that took root beneath the tree. It disguised itself among a bed of poison ivy that I was ignoring, which is how it became well-established. Wonder Spouse sprayed it with herbicide last spring, which knocked it back considerably. But it’s still there, biding its time until I forget about it. But I am determined that this latest invader will not gain permanent residence on our land.
I’m also watching for what is likely the inevitable incursion of kudzu. It dominates the property directly across the street from me. It would have crossed the road to my land years ago if the state didn’t mow it off the road every growing season. I can feel it plotting its invasion, perhaps via the drainage pipes beneath the bridge on my road that permits access for the creek that adjoins our property.
I know I’m not the only Piedmont homeowner battling invasive non-native plants. My blog has recently been visited by a number of viewers searching for information on controlling invasive plants. I have reluctantly concluded that unless your invader is just establishing itself in your yard, trying to pull it up manually will not control it. Herbicides seem to be the only option that will work in most cases. In my yard, deer will nibble on English Ivy in the dead of winter, but they never touch the Japanese Stiltgrass. I’ve read that even goats — known for happily devouring ivy, kudzu, and most any other plant in their paths — will not eat Japanese Stiltgrass.
Japanese Stiltgrass is creeping up the slopes of my friend’s new yard, working its way up from the intermittent drainage way below. That’s its favorite mode of transportation — water, which is why my floodplain is so plagued by it. I’ve resisted herbicides for fear of what they will do to my abundant frogs and salamanders, and the few fish still inhabiting my creek. But the literature states that the key is to use herbicides that do not contain an ingredient called a surfactant, because this is what causes the poison to stick to wildlife and hurt it. This link suggests herbicides that will kill this grass and are supposed to be safe in wetlands.
Wonder Spouse and I are planning on trying this weapon against our increasing infestation of Japanese Stiltgrass. I felt better about trying this weapon after talking with the curator of the Habitat Gardens at the NC Botanical Garden. She told me that she’s using it in her yard to battle this invader. She said the secret is to apply the herbicide consistently for five years — the amount of time the seeds of this grass remain viable in the soil.
I hate using herbicides, but there is no way Wonder Spouse and I can manually remove the invaders fast enough to prevent their spread on my land. I’m going to encourage my friend to begin using them now to prevent her from having my kind of problems. Right now, her land — the property that afflicted me with temporary forest envy — is about 20 years behind mine in invasive plant incursions. It’s been protected by the large stretch of contiguous forest it adjoins and its distance from major roads. But they must remove all the privet hedges planted by the previous owner immediately. And they must start applying wetland-safe herbicides to their Japanese Stiltgrass now — before their yard starts looking like mine.
For those of you wondering why I am so passionate on this issue, I refer you to my previous posts on this topic here and here and here. I truly believe that this is a battle we cannot afford to lose, folks.
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.
Autumn is a great time for patrolling your yard/garden. As frost kills formerly lush vegetation, areas hidden by summer are revealed. When I removed a mountain of dead Japanese Stiltgrass from a spot in my north garden yesterday, I discovered a thriving, still-green native blueberry that I planted three years ago. The hideous invasive grass had grown so fast and thickly that I forgot the little blueberry was there. I apologized for the neglect, but fortunately, I don’t think the blueberry was much hindered.
The best surprises yesterday appeared as Wonder Spouse and I walked beside our creek. We’ve been very dry here; we’ll likely be placed into the Abnormally Dry category by the meteorologists next week, unless the rain promised for tomorrow is much more bountiful than predicted. Despite the drought, our creek has more water in it than is usual for such conditions. The water itself barely flows. These signs tell me that beavers are working downstream; their dams prevent the creek water level from dropping. Local inhabitants have noticed the change.
Perched on brown leaves recently discarded by towering Sycamores, we discovered two very bright Green Treefrogs nearly side by side. In Summer’s greenness, I would certainly have passed right by them, but their color contrasted vividly with the browning landscape, making them impossible to miss.
The link above notes these are mostly inhabitants of our state’s coastal plain, but they’ve been creeping west of late. From the recording of their call and previous sightings on rainy summer nights when they climb our windows seeking insects, I know that this species has been part of our wetland for at least 20 years. The frog in the top photo was larger than its companion here:
Both frogs seemed astonished that they were spotted. Perhaps the water level in the creek and the unseasonably warm air made them think they were still camouflaged by Summer’s green cloak. We wished them well, advised them to seek warmer quarters ahead of the latest cold front due tomorrow, and continued upstream.
After only a few steps, as we passed a deeper spot in the creek, several ducks flew up and away in a whoosh of wingbeats. They departed so quickly that we didn’t get a good look, but by their size and general conformation, we suspect they were Mallards. The source I linked to says these ducks are now fairly common throughout my state, and our environment seems to be exactly what they seek this time of year. During Spring, I often see Mallards, Wood Ducks, and some years even Canada Geese. All three species have raised young ones in our wetland.
Right now, the recently arrived beavers are far enough downstream from us that we are gaining the benefits of their presence without any negative consequences. As our forest goes bare for Winter, our trusty binoculars will get much use as we observe increased numbers of wetland-loving wildlife. I confess it is possible for me to lose hours this way.
But beavers are hungry rodents, ever expanding their reach to fell trees for food and dam-building. If they approach too closely, the creek will jump its banks and create a shallow pond across our floodplain. The last time this happened, the water covered an acre and a half, trees were being felled at alarming rates, and those that still stood were dying as the water deprived their roots of oxygen. When this happened, we felt obliged to take steps we did not want to take. I hope circumstances won’t force us there this time.
We made all of these discoveries from one brief Autumn walk with eyes open and ears sharpened. I encourage all my readers to try this. Step outside, into your garden or onto a nature trail. Turn off your electronic devices, remove ear buds. Walk softly through the landscape with your senses tuned for subtle changes. When you really look, you will see.
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.