When you’ve spent years immersed — often literally! — in invasive plant management, seasonal
changes become associated with certain species. This is particularly true of Virginia’s most
widespread forest-invading annual grass, Microstegium vimineum or Japanese stiltgrass, as it is
most commonly known. August might mean vacations or back-to-school to most, but for me it
signals a top priority: time to confront stiltgrass once again.
The reason is simple: it’s in late August and early September that stiltgrass is on the verge of
flowering and going to seed. To effectively interrupt that reproduction cycle, you have to mow,
whack, or pull stiltgrass neither too early nor too late. In Richmond, the time is NOW!. So if you
recognize this habitat destroyer from your own yard (check street edges where its abundant
seeds can hitch a ride downstream by way of stormwater runoff), please dedicate some time
this holiday weekend to cutting it off at the pass (actually, you will want to cut it right down to
I wrote about stiltgrass management a year ago in the Urban Forest Dweller feature August is
for Defeating Stiltgrass where you can find what you need for identification and control
recommendations. Whether cutting or pulling, be sure to keep an eye out for known or
suspected native plants and work around them. They are our allies, and getting rid of stiltgrass
is essential to sustaining late summer and early fall wildflowers and other native plants.
Their own fire
Are on the trees, the fireflies
Around the house with flowers.
Matsuo Basho (1644-1694)
In November, I wait and watch for the migratory buffleheads to arrive on the James, above and below the Z Dam. Usually, they’ve begun their antic foraging dives by Thanksgiving, but no later than the first week of December.
In late May I look for another there-and-gone creature: the firefly, or lightning bug if you prefer. There are 2,000 species of fireflies worldwide, including the synchronous Photinus carolinus, one of 19 species native to Great Smoky Mountains National Park. It’s Photinus pyralis, the common eastern firefly, you see in yards and parks in Richmond. Fireflies belong to the order Coleoptera and the family Lampyridae; they are beetles, not flies. Their bioluminescent communication results from a complex chemical conversion of energy into light. Firefly adulthood lasts a matter of weeks, long enough to mate and lay hundreds of eggs. But the larvae live one to two years under bark and in soil, leaf litter, and other organic rot before pupating in the warm, humid conditions of spring.
On April 29th I saw a single member of the advance guard, which is not unusual. I knew at least a month would pass before the flashes in our yard multiplied. Then came a nearly record-breaking dry May with just 0.6 inches of rain over 30 days. The month started out warm, but the second half turned much cooler. As each evening turned into a firefly no-show I began to wonder if the weather had made for a firefly bust. The beginning of June brought rain and plenty of it, but was it too late? Had the critical window for firefly pupation from larvae to adults slammed shut?
Skimming the internet suggested that yes, since firefly metamorphosis into adulthood depends on wet, warm conditions, Richmond’s weather may have impacted maturation of larvae as well as their primary food source—snails and slugs. I adjusted my expectations, and we went to Highland County for a long weekend where in the dusk the fireflies rose from the grassy fields into the tree tops to mingle with the emerging stars.
As of June 13th, my own wooded yard was hosting just a smattering of fireflies, far fewer than in past years, and I’d yet to come across any at rest on vegetation in the daytime as I usually do. I next queried Richmond’s own renowned beetle expert, entomologist Dr. Art Evans, who observed that, “the relatively cool, dry weather thus far this season might have dampened firefly activity in some areas”, but that just miles across the river on Richmond’s northside—as well as elsewhere in the state—he was experiencing greater abundance of fireflies than he had in years. So anecdotally, it seems that there can be significant local variations in firefly population size and emergence timing, perhaps a result of differences in habitat conditions.
The tide turned on June 19th. Dusk brought at least a tripling of levitating sparks, which doubled a few nights later. My son and I wandered the yard, following the fireflies’ lead, then sat and took in the hypnotic show. It seems that all I needed was the patience of fireflies.
If fireflies are an uncommon sight for you in Richmond regardless of the year, you might be wondering why. Dr. Evans further noted, “Drought, loss of good plant cover, pesticide use, and light pollution all take their toll on urban and suburban firefly populations.”
Mowing, blowing, and chemically treating a yard decimate habitat. Dusk to dawn artificial light is a habitat disruptor for all species, most dramatically for the nocturnal. In the case of fireflies, those bioluminescent signals from males to females only work in naturally falling darkness. Light pollution is a factor in overall diminishing insect diversity and abundance, and its impact on fireflies is a particular area of research.
So leave the leaves and allow for a less manicured yard favoring native plant species, including grasses. Improve your home outdoor lighting, and consider becoming an advocate for responsible lighting policies and practices that are better for our environment—natural and built—and for every living thing, including fireflies and us.
Why turn away
Kobayashi Issa (1763-1828)
English version by Lucien Stryk and Takashi Ikemoto
Firefly Conservation and Research: https://www.firefly.org/
International Dark-Sky Association: https://www.darksky.org/
The synchronous firefly species of Great Smoky Mountains National Park: https://www.nps.gov/grsm/learn/nature/fireflies.htm
In his final work, Wildwood: A Journey Through Trees, British nature writer and activist Roger Deakin overlooks the River Wye in western England and considers the influence of woodland ecology on the life history of a river. He reminds readers of the life-giving “vintage rot” of decaying trees, which while still in their healthy middle age will have dead branches, dropped or not, and as age advances, hollows expanding within their trunks. He closes his chapter with a visit to a churchyard where he squeezes inside the hollow of a 1,000-year-old yew tree, looking up into the illumined and illuminating “lantern of its twisted trunk”. The tree was nonetheless in full foliage, blackbirds feasting on its berries.
I recalled Deakin’s enchanting passage as I noticed the ubiquitous signs of “vintage rot” all around me. It began while brushing my teeth one morning. My gaze through the window was level with the excavated knothole on a slender oak tree. Out popped a Carolina chickadee. My most beloved cavity dweller! “Cavity” is not a word with positive associations (particularly while brushing one’s teeth), but cavities, when in trees, are very good indeed. A few days later, over my morning coffee, I observed from our kitchen window a pair of squirrels — mouths stuffed with leaves — using both the front and back doors of their nest hidden within this white oak:
The Bufflehead diving ducks that arrive on our part of the James River around the end of November nest in cavities. So do the Wood ducks I’ve been lucky enough just twice to see high in a tree, seeking a suitable nest site near water. Prothonotary Warblers, Bluebirds, Woodpeckers, Tree Swallows, Purple Martins, Screech Owls and Barred Owls . . . All cavity-nesters.
A few months ago, arborist and Urban Forest Dweller contributor Aidan Stewart made “The Case for Keeping Your Backyard Habitat Standing”. It included this illustrative graphic that bears repeating:
A tree cavity doesn’t have to house mammals or birds to provide habitat. The decomposers that feast on the decaying wood are themselves food, and insects and insect larvae found in rotting wood (and leaf litter, my other favorite decomposing organic matter!) are essential to the survival of hatchling songbirds. Or a cavity might be the perfect water catchment system.
Some trees invite curious investigation and show no signs of weakness despite sizable hollows in their trunks.
In the opening chapter of her 1975 Pulitzer Prize winner Pilgrim at Tinker Creek–lived and written near Roanoke — Annie Dillard proclaims, “I am no scientist. I explore the neighborhood.” She finds that, as with everything “nibbled and nibbling”, “we the living are . . . pitted and scarred and broken through a frayed and beautiful land.” Just as we do, trees age, sustain damage, sustain life, carry on. Explore your neighborhood. You will not find a 1,000-year-old yew, but you will find a tree that is a doorway.
Valentine’s Day has come and gone but it’s not too late to show Richmond’s trees some love.
Since 2017, the James River Park System Invasive Plant Task Force has hosted a week of special events to observe National Invasive Species Awareness Week at the end of February. This year is, of course, different. No guided group walks, no information booth ideally situated near RVA Goats, and no crowded party to wrap up the week.
NISAW 2021 is instead an opportunity to put the park system’s (and all of Richmond’s) trees in the spotlight, offering ample opportunities to save the life of a park tree while learning how to do the same for trees in your own neighborhood. Task Force members will be leading volunteer events—with limited numbers of participants— at Belle Isle, Pony Pasture, Chapel Island, Reedy Creek, Buttermilk Trail, and Huguenot Flatwater. Find out more on the JRPS Invasive Plant Task Force website where you also can access the volunteer calendar for details and contact information.
Last weekend’s ice storm on top of Friday’s snow demonstrated the increased fall risk to when weakened and weighted by thick invasive vines and their drapery of foliage. Trees crashing down under the weight of ice and snow don’t just knock out electricity; they block roads and crush roofs and cars—and they can kill. Invasive plant control is essential tree care.
A couple of months ago I wrote here about how invasive vines—primarily English ivy and wintercreeper—add to the stressors already compromising the health and survival of trees, and last month I offered step-by-step guidance to “freeing trees”. This month my JRPS Invasive Plant Task Force colleagues and I welcome the chance to enlist more tree heroes in the fight to save Richmond’s tree canopy. Please join us at one of our JRPS project areas for a hands-on “Free-A-Tree” experience throughout the rest of February. Then bring those skills back to your neighborhood. We can save Richmond’s urban canopy, one tree at a time.
Laura Greenleaf is a Certified Virginia Master Naturalist and a founding steering committee member of the James River Park System Invasive Plant Task Force. She lives near the Pony Pasture section of the park system.
The plight of Richmond’s trees inspired the founding of the JRPS Invasive Plant Task Force exactly six years ago. In winter it’s impossible to overlook how many of our trees are in a death grip of invasive vines, and it’s the ideal time for freeing trees from invasive English ivy and wintercreeper, the two main culprits consuming so much of Richmond’s canopy. In last month’s article, I explained how invasive vine cover harms trees, encouraging Richmonders to take action to stop the destructive onslaught in their neighborhoods. Now here’s a guide for “freeing trees” so you can be a tree hero without ever leaving home.
First, a few basic principles:
Step-by-Step Instructions to Free-A-Tree
The holly and the ivy
When they are both full grown,
Of all the trees that are in the wood,
The holly bears the crown.
— traditional British folk Christmas carol
Bluebirds, Downy Woodpeckers, Carolina Wrens, Tufted Titmice, and the bossy gangs of American Robins are regular visitors in December, but none as delightful as the Chickadees that nimbly navigate the interior of the berry-laden hollies beyond my kitchen window.
The American holly (Ilex opaca) itself is a favorite of mine; a local woodland denizen I did not grow up with in the northern Blue Ridge, it is somehow forever novel to me. My son and I recently conducted an American holly survey in our yard. We counted fifteen trees taller than ourselves, a couple of them approaching their mature height of around 40 feet. They are about evenly divided among males and females, the latter having a particularly robust season of fruit production. Shrubbier versions tend to nuzzle up against the larger hardwoods, suggesting that perhaps a Chickadee forbear planted the seed from an overhead branch. Innumerable diminutive offspring are nestled in the leaf litter, thriving in the acidic soil.
But there’s no love lost between me and another evergreen Richmond resident, the one that six years ago inspired the founding of the James River Park System Invasive Plant Task Force: English Ivy (Hedera helix). This season of dormancy drops the deciduous curtain and reveals the extent to which invasive English ivy (and wintercreeper) are engulfing Richmond’s landscape.
Ivy carpets “natural” areas not already converted to lawn and, most heartbreakingly, enwraps trees until they are less trees than they are scaffolding for the ivy. Look for vine-draped trees as you travel our city and its neighbors and ivy’s threat to our tree canopy quickly becomes apparent. Planting new trees in neighborhoods bereft of tree cover is crucial for the well-being of our city, but we also must rescue our existing mature trees that are perishing under invasive vines.
Trees imprisoned by English ivy or wintercreeper are dying. The dense woven web of vines traps moisture against their bark, inviting decay and disease. The ivy and wintercreeper root systems rob a tree of soil nutrients and water. At the point where you can no longer see the tree’s own foliage for the vines, the tree can no longer effectively photosynthesize to produce its energy. And a tree so weakened — and then draped in heavy curtains of vines — is more likely to crash down in wind or under ice or snow.
Nor can such a tree serve the habitat needs of our native wildlife. And where trees are surrounded by ivy and wintercreeper groundcover, the monoculture of vines likewise smothers native plants and prevents the successive growth of tree seedlings. The result is a “dead-zone” loss of habitat, while the vertical growth —through flowering, fruiting, and seed dispersal by birds deprived of native food sources — contributes to the perpetual invasive spread that does not observe any boundary between private property and our public parks.
We can reverse this trend by being good stewards of the trees growing on our own property and at our businesses, schools, and houses of worship. It’s imperative that we prevent English ivy from overtaking trees to begin with and to intervene to save trees already suffering. This can be a DIY project for anyone with pruners, a handsaw, and good instructions, or for yard-care companies. Imagine what we could accomplish if we transferred some of the time, energy, and money spent on removing leaves to saving trees!
Winter is the time to save your trees: it isn’t hot, humid and buggy; the trees are easily accessible; and the evergreen vines are not dormant. Once treated, wintercreeper will begin drooping and browning almost immediately, while English ivy will take longer to wither.
Richmond Tree Stewards provide excellent guidance on English ivy on their website, and Arlington Regional Master Naturalists offer simple instructions on removal on their Choking Hazard page. Next month in Urban Forest Dweller I will share my own how-to guide to Free-A-Tree, so make your New Year’s resolution now: in 2021 let’s save Richmond’s trees.
Laura Greenleaf is a Certified Virginia Master Naturalist and a founding steering committee member of the James River Park System Invasive Plant Task Force. She lives near the Pony Pasture section of the James River Park.
As I write, wind lashes the bending trees and rust-golden leaves whirl past my window. Great leaf-drifts from our hickory, tulip, black gum, sweetgum, beech, and white, red and post oak trees erase yesterday’s raking and sweeping of walkway and deck. Elsewhere in the neighborhood trash bags bursting with leaves are set out for trash collection while long ridges of leaf piles await their demise by vacuum suction.
I know I’m not entirely alone in declining to wage war on leaves, but I suspect I don’t have much company in my anguish at the sight of leaves destined for landfills. Why grieve for leaves? As with all plant life, they are where the food web begins its great feast, and to borrow from Walt Whitman, they too contain multitudes (rather literally).
I also understand the appeal of some lawn, so I’m not about to suggest anyone abandon theirs. And I know that my own wooded nearly half-acre accommodates far more leaf piles than most city yards. But we all can make modest changes that work for our particular yard. We can reserve an inconspicuous corner for a leaf pile, rake lawn leaves into naturalized areas, beds, or borders, construct wire leaf composters for garden mulch, or reach first for gentler rakes and brooms rather than polluting blowers that are hard on plants, soil, and the hidden life in leaves. Consider the benefits of a different approach to autumn leaves:
Six Reasons to Leave—at least some of—the Leaves
Trees: Mother nature doesn’t make trash. She’s a repurposer and recycler. Trees are producers, making their own food with their leaves via photosynthesis. Shortening fall days and dropping temperatures shut down this production. With green chlorophyll extinguished, the leaves’ true colors emerge in a process called senescence that transfers remaining energy to the tree before the leaves drop (abscission).
But wait! The tree still isn’t done with those leaves. The layers of decomposing leaves that blanket a tree’s root system continue to nourish that tree and its neighbors, releasing nutrients into the soil and keeping it moist. Our trees are stressed enough as it is from droughts, extended record-high summer heat, invasive insects, and disease, plus the heavy invasive wintercreeper and English ivy vine cover that burdens so much of Richmond’s tree canopy. Let’s not scrape away their very own life support system. Senescence is not obsolescence.
Moving outward in the food web we’ll find other species desperate for us to loosen up and get messy with the yard, like woodland box turtles, which forage for meals in leaf litter and over-winter, buried several centimeters beneath it. Amphibians like salamanders, toads, and frogs and small mammals like chipmunks also make their homes in deep layers of leaves.
So, leave the leaves – but not in the street. My own “leaf management” includes regularly raking and sweeping the natural fall of leaves at the street edge back onto our property and relocating heaps of leaves by wheelbarrow and tarp into setback areas. Here they can do their job of absorbing rain, snow, and ice as they decompose and slowly releasing their moisture into the soil.
The noise pollution is so overwhelming that it’s easy to forget that these small single-cycle engines pack big pollution from emissions plus the airborne clouds of allergens, mold, and (how to put this politely?) animal fecal matter their powerful blasts stir up.
Leaf blowers pose significant respiratory, cardiovascular, and hearing health risks to their users and impact neighbors, pedestrians, runners, and cyclists. Everyone’s health and well-being are good reasons to at least reduce the excessive reliance on leaf blowers. You don’t have to give them up entirely, but consider limiting their use to more targeted tasks, switching to electric models, and taking it easier on the leaves.
You know the slogan “Peace begins at home”? May it begin in our yards.
Laura Greenleaf is a Certified Virginia Master Naturalist and a founding steering committee member of the James River Park System Invasive Plant Task Force. She lives near the Pony Pasture section of the park system.
Have you ever seen a Cedar Waxwing? This year-round avian resident of Virginia is one of our most striking backyard birds. Seal-sleek, mysteriously masked, and with yellow and red accents brilliant as fresh paint, it is a startling sight for bird watchers more accustomed to nuthatches and chickadees.
In the nine years I’ve lived just south of the James near the park system, I’ve seen just two Cedar Waxwings in my yard. Both were dead, less than a hundred yards from a neighboring large expanse of invasive Nandina (or Heavenly Bamboo) loaded with berries. In a criminal case, this would be circumstantial evidence, and as science, it’s merely anecdotal. But the loss of those gorgeous birds focused my attention on an invasive plant species that previously hadn’t stood out in the crowded invasives field. I soon learned that Cedar Waxwings have a habit of gorging themselves on the toxic Nandina berries.
Nandina domestica, native to Asia, was first introduced to this country as an ornamental in the 1800s and became a popular landscaping choice throughout the southeast where it has since begun invading forests from North Carolina to Texas. Its berries contain cyanide and other alkaloids that produce hydrogen cyanide, albeit at a low toxicity. Though not yet listed as invasive in Virginia, it does escape cultivation here, including into the James River Park System. But if you would like to see your Cedar Waxwings with life left in their bodies, that’s reason enough to make Nandina a priority for removal, even if you just start with the berries.
This is because Cedar Waxwings tend toward what I politely will term “particular feeding habits.” That is, they are prone to over-eating. They will stuff themselves until they just can’t fit in one more berry. Nandina’s low-toxicity berries thus deliver deadly doses in large serving sizes, particularly in late winter and early spring when more preferable food sources are scarce. There are no documented avian deaths directly linked to Nandina consumption except with Cedar Waxwings. The most well-known case occurred in Georgia in April of 2009 when Tifton Veterinary Diagnostic and Investigational Laboratory conducted a post-mortem on five individuals of many waxwings found dead in a residential yard.
Reducing Our City’s Abundant Nandina
Nandina is ubiquitous in Richmond neighborhoods both north and south of the river, whether as unruly volunteers along alleyways or as carefully manicured hedges. If you decide to curb the spread of Nandina, here is what you should know:
Replace Nandina in Your Landscape with Natives Shrubs and Trees
If fondness for Nandina’s bright evergreen foliage and holiday-decoration ready berries is making you wring your hands with reluctance, consider the many native berry-producing shrub and tree species that would be far more at home in your Richmond yard and support our indigenous songbird species, including Cedar Waxwings. Trees and shrubs native to our area include: American Holly, Eastern Redcedar, Common Hackberry, Serviceberry, multiple Viburnum species, Spicebush, Winterberry, and American Beauty-berry.
For inspiration and motivation, one more photo of a splendid Cedar Waxwing . . .
Laura Greenleaf is a Certified Virginia Master Naturalist and a founding steering committee member of the James River Park System Invasive Plant Task Force.
First it’s the crickets in early morning. Next it’s the light: the shifting, slanting gentle light of late afternoon. We are turning toward the night-day balance of the autumn equinox. The crickets and the angle of the light seem to signal that it’s a good time to be still and quiet, to pay attention. The wildflowers of waning summer are one of the rewards. In late August and early September there is much to see in bloom along the river — and hopefully in your own yard. Let’s start there.
I was busy listening to the crickets through an open window and avoiding my work when I noticed—really noticed—the seasonal profusion of Tick-trefoil accenting our walkway and paths.
If the common name doesn’t put you off, the seedpods to come will really grab you (mostly by your pantlegs). Tick-trefoil — genus Desmodium — is a perennial legume spread by its seeds. There are 20 Desmodium species native to Virginia, at least nine of which can be found in the Richmond area. I haven’t gotten a positive identification on mine, but my best guess is Desmodium glabellum. I suspect that Desmodium in yards frequently suffers the fate of native
species vulnerable to being labeled as “weeds”, but those delicate orchid-like flowers on wispy stems are a late summer joy and their seeds are a valuable wildlife food source while the foliage provides good cover.
This particular species of Desmodium likes the dry upland woods of our yard. But along the James River nearby, other native species are heralding the end of summer. What can you see while taking a walk along the river? Here are just a handful:
“Thrives in diverse environments and adapts readily to varied conditions. A prolific producer with multiple strategies to achieve success. Makes the most of opportunities.”
If invasive plants had their own LinkedIn accounts, this might be on the profile Japanese stiltgrass (Microstegium vimenium) and August is the month of its ascendency when it densely crowds roadsides, drainage ditches, utility rights of way, trail edges, stream banks, and just about any place where a little sunlight interrupts the shade, particularly where the ground has been disturbed.
Japanese stiltgrass was my “gateway invasive”—the species that introduced me to invasive plant ecology when I first became a Virginia Master Naturalist ten years ago because it had already dramatically altered the northern Blue Ridge woodlands where I’d grown up. In the invasive plant geek parlor game of “If you were a time-traveling superhero, what invasive plant species would you stop?” I
don’t waffle over my answer. In the mountains and piedmont, August is the season of stiltgrass dread while the fall and winter holidays bring the despair of the inescapable posthumous hummocks carpeting the forest floor. (It was dried-out dead stiltgrass that first invaded North America, used as packing material and loaded with seeds.)
But don’t let me bring you down, read on!
Stiltgrass is an annual grass from Asia that reproduces primarily through seed production. It’s one of the most destructive invasive plants in North America and nearly ubiquitous in eastern deciduous forests where, by late summer, it forms stiltgrass seas that turn to vast masses of dried “thatch” in winter.
No invasive plant species proves that “timing is everything” quite like stiltgrass. Manage it properly in late summer prior to flowering–every year it grows–and you can curb its spread, even eliminate incipient incursions. But misguidedly mow, weed whack, or pull it after it’s gone to seed and you’ve just been an unwitting accomplice in an ecological crime. Do the same too early, in June or July, and stiltgrass will respond with vigorous new growth.
How does stiltgrass stand out within the ranks of invasive plants that by definition dominate the environments they invade?
Each plant can produce as many as 1,000 seeds.
Those seeds can remain viable in the ground for up to five years, possibly longer (germination rates do drop off dramatically after two or three years).
Stiltgrass spreads in sun or shade, dry or moist conditions.
But it particularly loves wetlands and riparian areas (adjacent to streams, creeks, and rivers) and the flowing water carries stiltgrass seeds downstream to new outposts.
Stiltgrass also gets some help from us, animals, and the elements:
Seeds hitchhike on the bottoms of our hiking boots and the tires of vehicles and machinery.
White-tailed deer–particularly where populations are too high– heavily browse native plants, giving stiltgrass an advantage, while seeds get a ride on hooves and hides.
Off-leash (and off-trail) dogs also can transport seeds on their fur.
Stormwater runoff transports and deposits stiltgrass seeds.
Land management and landscaping practices in natural areas that disturb soils and cut back native species woody and herbaceous vegetation set the stage for stiltgrass colonization.
Identifying stiltgrass is easy, but there are native grasses that might become cases of mistaken identity. Here are the basics:
Stiltgrass leaves are 2 to 4 inches long and about half an inch wide,
well-spaced alternately on the stem, with smooth edges
Leaves sport a distinctive silvery, off-center mid-rib
At maturity, stiltgrass can reach a height of three feet or more
Stems often branch in multiples from the base
Seed heads extend from delicate stalks Alabama Natural Resources provides this excellent Field Guide to Identification of Japanese
Stiltgrass (with comparisons to look-a-like species).
So now that you’ve just realized you have stiltgrass on your property, what should you do about it? Here is the one nice thing I have to say about stiltgrass: it has a weak root system that pulls up easily. If you have just small patches of stiltgrass, hand pulling is the way to go. Hand pulling also allows you to carefully avoid collateral damage to native plant species, including grasses like Virginia white-grass and deer tongue grass. If you have larger expanses of stiltgrass and you’re confident that no native plants are hiding out, you can use a stringed weed trimmer to cut the stiltgrass as close to the ground as possible. I still use the (freshly sharpened) sickles and weed whips my family used to open trails and
other clearings at home in the ‘70s and ‘80s . . . . trails and clearings that were colonized by stiltgrass by the new century!
Whether manual or mechanical, you want to tackle stiltgrass soon, and since it does not uniformly go to seed at the same time in all habitats, inspect it closely to make sure seeds have not yet formed. For more detailed information on managing Japanese stiltgrass, check out this fact sheet from Blue Ridge PRISM.
Laura Greenleaf is a Certified Virginia Master Naturalist and a founding steering committee member of the James River Park System Invasive Plant Task Force. She lives near the Pony Pasture section of the JRPS.
“Invasive plant species are an underappreciated threat to our native plants and wildlife. Bradford pear is one that was introduced intentionally, but has shown to have undesirable traits horticulturally and ecologically. It should be abandoned in favor of native species.”
–Kevin Heffernan, DCR Natural Heritage Stewardship Biologist Richmond Zen Head Priest
A tree stump isn’t usually something that pleases me. The exception: the stumps of invasive trees — Tree of Heaven (Ailanthus altissima), Royal Paulownia (Paulownia tomentosa), Mimosa (Albizia julibrissin), Norway Maple (Acer platanoides), and yes, Bradford pear (Pyrus calleryana). These species impoverish our natural areas and do little to enhance the health of our built environment when compared to the native tree species they displace.
Beginning in 1909, the Bradford pear was introduced from its native China and Taiwan as an antidote to the fire blight epidemic in pear fruit trees. The Bradford pear (or Callery pear) — with its uniform shape, medium mature height, ample shade, and abundant blossoms — became a common ornamental presence in yards and parks and along streets throughout the Southeast United States. The tree produces sterile fruit, but by the turn of the 21st-century hybridization with cultivars triggered fertile seed dispersal across the Southern landscape.
Since then the Bradford pear has risen to the top of our least-wanted invasive plant lists. The Virginia Department of Conservation and Recreation’s Natural Heritage program ranks it as having medium invasiveness throughout Virginia. The South Carolina Forestry Commission and Clemson University have partnered to pioneer the “Bradford Pear Bounty Program”, motivating citizens to take down their Bradfords in exchange for native tree replacements.
In mid-March, my last trip down interstate 95 to Richmond before the pandemic lockdown displayed just how much Bradford colonization has advanced; highway edges and open areas by interchanges were dense with a monoculture of blooms that are no signifier of a Virginia spring. I took some comfort in knowing that I’d already been part of a small effort to curb the Bradford pear invasion in a Richmond city park.
The previous November members of Richmond Zen, having successfully applied for a Community Roots grant from Richmond Tree Stewards, partnered with Department of Parks and Recreation staff at Forest Hill Park and the Tree Stewards to replace the avenue of Bradford pears that previously stretched down a hill below The Stone House.
The pear replacements had to conform to the public walkway’s formal setting and purpose—a different set of goals and criteria than when planning for habitat restoration—and species selection had to further take into account the availability of saplings rather than bareroot seedlings (the go-to for habitat restoration projects). The additional goals of adding new species to Forest Hill Park’s inventory and striking a symmetrical balance to the walkway arrived at alternating lines of Valley Forge Elm (Dutch Elm Disease-resistant cultivar of Ulmus americana) and Nuttall Oak (Quercus nuttalli). One more pre-planting task remained: notifying park neighbors and visitors of what was to come and understandably registers as a shock and a loss – chainsaws leaving behind tree stumps, followed by their removal.
On the sharply cold morning of November 9th, Richmond Zen’s sangha members, family, and friends gathered with Richmond Tree Steward Jesse Wright and Forest Hill Park staff. Within a matter of hours, dormant new life was in the ground.
Seven months later, after a cool and rainy May, the time came to tend the new trees through a Richmond summer. With support from Parks and Recreation, Richmond Zen volunteers are watering the trees on a weekly basis.
Do you have a Bradford pear that you would like to replace, but need help with species selection? Look no further than the Native Plants for Virginia’s Capital Region guide. Consider Serviceberry species, Sourwood, and Sweetbay Magnolia among others.
For a deeper dive into the downsides of Pyrus calleryana check out this recorded webinar from the Virginia Association of Forest Health Professionals – Pretty But Pungent: the Curious Case of the Callery Pear.
Laura Greenleaf is a Certified Virginia Master Naturalist and a founding steering committee member of the James River Park System Invasive Plant Task Force.
Chionanthus virginicus. I type the Latin genus and species into the Digital Atlas of the Virginia Flora and am surprised by the map the entry returns: a red dot in every single Virginia county indicating that Fringetree occurs statewide, “frequent to common throughout”, from dry upland forests to streams and wetlands.
How then did I manage to grow up and live in Virginia’s Blue Ridge, Shenandoah Valley, and northern Piedmont and not come to know this tree by name until moving within the city limits of Richmond? It can take a lifetime — and sometimes just a single tree — to cultivate attention. I’ve known just one naturally occurring Chionanthus virginicus in the city, and no sooner did I make its acquaintance than it was gone—wiped out by a clearcut for new construction. The ground where that woodland Fringetree would now be blooming is paved with concrete and planted with geometric arrangements of Crape Myrtle and other ornamental, non-native landscaping staples.
Though an understory species so modest in size as to sometimes be classified as a large shrub rather than a small tree, Fringetree is a striking attention-getter. In late spring, its frothy profusion of dangling blooms proves both its common name and the etymology of Chionanthus: snow and flower. The fragrant flowers appear on both male and female trees (most abundantly cloud-like on males), but in order to produce the early fall dark-blue fruit so beneficial to native songbirds, males and females must grow in proximity.
Like the ash trees — the species in the genus Fraxinus — that we are losing to the Emerald Ash Borer, Chionanthus virginicus is one of just a few members of the family Oleaceae native to North America. And also like the ashes, it is a host plant to the Fawn sphinx moth (Sphinx kalmiae) as well as to the Rustic sphinx moth (Manduca rustica). According to Native Plants for Virginia’s Capital Region, Fringetree hosts eight species of native caterpillars on its foliage before it even gets around to luring pollinators with its flowers and feeding songbirds with its berries. The ubiquitous non-indigenous crape myrtles that have “replaced” that wild Fringetree cannot support a single specialist insect species.
The nursery-sourced Chionanthus virginicus most commonly seen in landscape plantings are typically multi-stemmed shrubs no more than 8 to 10 feet tall. But the forest dweller I knew was at least twice that height on a single branching trunk. I was so taken by that tree that, before its demise, I purchased my own Fringetree at the annual plant sale at Blandy Farm, the State Arboretum of Virginia. Despite the species’ unfussy reputation, the planting location I chose proved to be less than ideal or perhaps I unintentionally committed a local ecotype mismatch. This year the top half of its growth has died. Prior to this reversal in health, my Chionanthus had tripled in height while its stem remained no thicker than a Sharpie. Slow growers, these Fringetrees. I wonder how many Mays the full-grown wild Chionthanus had bloomed before it caught my eye, how many years of growth ended with one thoughtless swipe of a chainsaw.
So Chionthanus virginicus asks not only for our attention but for our patience. I look now for sources of seedlings or saplings that will come closest to what nature bestows in the woods. I contemplate my yard’s more sunlit canopy openings and richer soils. Whatever this fall brings, I intend to be planting Fringetrees.
Laura Greenleaf is a Certified Virginia Master Naturalist and a founding steering committee member of the James River Park System Invasive Plant Task Force.
I knew it was coming. But that didn’t make the inevitable any less heartbreaking. Seven years ago I peeled off a loose hunk of bark from a fallen green ash tree in the northern Blue Ridge where I grew up and saw what I’d previously witnessed only on educational alerts – the serpentine “galleries” of the invasive Emerald Ash Borer (EAB) larvae.
By 2016 everywhere I looked I saw the defoliated crowns and “blonding” trunks of ash trees that were dying by the dozens (“blonding”—the shedding of bark—is the work of opportunistic woodpeckers mining the EAB larvae that are feeding on the tree’s vascular system, choking off water and nutrients). And just like back home in the mountains, a few years later I would discover I hadn’t realized how many ash trees lived in the James River Park System until they, too, started dying.
Deadly Invertebrate Invader
The aptly named Emerald Ash Borer, native to most of Asia from the Russian Far East to Japan, made its first documented appearance in North America in southeast Michigan in the summer of 2002 after most likely stowing away in cargo packing material made from wood. A year later it was detected in Fairfax County, Va. but was eradicated before its reconfirmation there in 2008. Regulatory quarantines on firewood ensued, distinctive purple monitoring traps deployed. But Emerald Ash Borer implacably spread throughout Virginia (with a 2019 Richmond region date-stamp) as well as to 35 U.S. states and the District of Columbia and five Canadian provinces, leaving tens of millions of dead ash trees in its wake. (For more on the biology and spread of EAB, visit the Virginia Department of Forestry’s EAB Story Map.)
Elegy for Fraxinus spp.
There are about 40 species of the genus Fraxinus worldwide, 16 in the United States, and of the four found in Virginia, White Ash (Fraxinus americana) and Green Ash (Fraxinus pennsylvanica) are the most common. Found throughout Virginia, White and Green Ash historically made up 2-3 percent of the forest composition and pulled duty as dependable residential and municipal shade trees.
In a dense forest environment, ash trees didn’t grab my attention. I underappreciated them. But Fraxinus is a giver—ecologically and culturally. Its wood is ideal for tool handles, furniture, veneers, and most iconically, baseball bats. Its loose clusters of pale green to nearly purple flowers fruit to flat, winged seeds that feed songbirds and mammals. According to entomologist Doug Tallamy, in Bringing Nature Home: How You Can Sustain Wildlife with Native Plants, Ash species in Eastern deciduous forests host 150 species of Lepidoptera (butterflies and moths). The National Park Service in the National Capital Region cites 27 insect species including moths, butterflies, and bees that are restricted to ash as their host plant.
Those specialized host relationships include our own native ash borers, but against the invasive Emerald Ash Borer the trees have no defenses; native trees and invasive insects did not co-evolve to develop adaptive checks and balances. The flashy invader reproduces prolifically, matures quickly, and spreads rapidly both under its own wing-power and by human actions. Where EAB has been present the longest, the mortality rate of Ash trees is nearly 100 percent. With them goes all that they gave—cooling shade, streambank stabilization, food and shelter for wildlife, and a mutually interdependent web of life whose loss is incalculable. In forests, the sunlit clearings they open in the canopy are ripe for colonization by invasive plant species (replanting hard-hit areas with a range of well-suited locally native tree species is a strategy for staving off invasives and fostering biodiversity).
The U.S. Forest Service has dubbed surviving ash trees “lingering ash” and these apparently resistant individuals (a different kind of one percent!) are the subject of long-term genetic research, a possible key to a future for Fraxinus.
For now, frontline response to this late stage of Emerald Ash Borer’s assault continues to focus on treatment of trees that haven’t yet succumbed. The Virginia Department of Forestry operates a cost-share reimbursement program available to individual property owners and organizations. In 2019 the James River Park System applied for and received cost-share grant funding and treated thirteen trees in the Huguenot Flatwater Woods and Pony Pasture park units. Since then, the park system partnered with the Invasive Plant Task Force (and its fiscal agent, Friends of the James River Park) to successfully apply for a private foundation grant that is now funding treatment of an additional 40 trees. Volunteers are identifying good candidates that haven’t suffered more than 30 percent canopy loss. If you notice a tree with a blue ring painted on its trunk: that’s a survivor receiving treatment on a two-year cycle.
Never say die
Reckoning that the Emerald Ash Borer was inexorably advancing toward the northern Blue Ridge, the same year I first suspected their presence I planted a half dozen green ash bareroot seedlings from the Virginia Department of Forestry in the woods where I had grown up and where ill-fated mature ash trees still gave the appearance of flourishing. If they survived, I reasoned, by the time they matured the Emerald Ash Borer might just be a bad memory. I wish I had planted more. Now I keep an eye on the canopy in Richmond’s parks, hoping to spot a survivor.
In my last article I turned my attention—and hopefully readers’ attention as well!–to the naturally occurring native plants all around us that can continue to thrive if we let them. This week let’s take a peek at just a few of the most adaptable spring and early summer-flowering shrubs and perennials native to the Richmond region to consider adding to your home.
(All photos are taken within the city of Richmond at the author’s home and at the Bayscape native plant garden at Good Shepherd Episcopal School.)
Green and Gold is a favorite of mine; it isn’t fussy and it spreads by stolons and runners making it a great ground cover in tough areas. It’s shade tolerant and has a long bloom-time.
Delicate and bright, Golden-alexanders prefer moist soil. Butterfly bonus: This is the host species to the Black Swallowtail.
Remarkably adaptable to different conditions, it’s no wonder that Golden Ragwort makes its home in every county in Virginia. Attracting pollinators while repelling most herbivores, Golden Ragwort’s full-skirted foliage and abundant bright blooms make it a great choice.
Seen here just before blooming, Blue-star is truly at home in Richmond, though it occurs infrequently in its limited range.
Skip the cultivars and make way for this shady woodland sign of spring that’s a favorite of native bees and butterflies.
Lyre-leaf Sage (Salvia lyrata) A wildflower that truly doesn’t care where it grows; from roadsides to woodlands, sun to shade, it tolerates both drought and temporary flooding. Lyre-leaf sage is a somewhat deer-resistant groundcover solution with much to offer pollinators including the larvae of several species.
All viburnums are “wildlife powerhouses,” their flowers feed native bees and other pollinators, while their berries are forage for songbirds.
Although it thrives with some full sun, Sweetspire can manage well in a mostly shady spot if it isn’t too dry. Sweetspire nectar is an insect magnet and its vibrant fall color is long-lasting.
If deer-browse is a problem, this is your go-to hedge. Ninebark tolerates a range of conditions and grows rapidly in a fountain-like form.
What do all those cultivars have over this ‘straight species’? Absolutely nothing. Full disclosure: Richmond is just outside of the Rosebay’s easternmost native range, but it’s just right in a spot by this writer’s porch.
Old habits die hard– especially when non-native ornamentals dominate the aisles of garden centers and the offerings of most landscaping companies — but a little effort and a fresh outlook are all it takes to cultivate habitat at home with native plants beautiful in form and bloom, all the more so because of the life they give.
If you don’t already have a copy, Native Plants for Virginia’s Capital Region is a must that’s available for order or download on the Plant Virginia Natives website. While not intended to be an exhaustive encyclopedia of native plants of our region, this well-organized and accessible guide is an excellent planning tool.
All plants in accompanying photos sourced from Garden Gate Landscape and Design, Reedy Creek Environmental, and Hill House Native Plants. You can find a list of native plant nurseries on the Virginia Native Plant Society website.
“Once in a golden hour
there fell to earth a seed
up there grew a flower
the people said, a weed.”
I memorized this little rhyme as a child because a framed version hung on my bedroom wall. But it means more to me now, as a certified Virginia Master Naturalist delighting in every appearance of a native plant in an area so devastated by overwhelmingly extensive invasive plant infestations.
Treasures still abound — often hidden in plain sight — in Richmond’s parks, along roadsides, and in unmanicured wooded yards. What generations of homeowners often dismissed as weeds have been largely displaced by turf grass lawns, exotic ornamental landscaping, and, increasingly, complete removal of leaf litter (an ecological term – leaves are not garbage, and we need to stop treating them as such). But some native plant species are particularly adept at hanging on given the slightest chance.
Attention is all it takes (no botanical expertise necessary) to truly see and appreciate the indigenous flora of our Fall Line ecosystem. Here is just a smattering of your fellow Richmond residents you may be encountering this spring:
Mayapple (Podophyllum peltatum L.) Found in every county in Virginia, the whimsical Mayapple is a familiar sign of spring in the Commonwealth and it thrives in our local woodlands, particularly well-shaded damp spots, maturing here well before May. The leaves are deeply palmate and if there are two, a single white flower will follow (visible only if you peek beneath the umbrella-like leaves) and later, the so-called “apple”.
Cut-leaf Toothwort (Cardamine concatenata) This diminutive spring ephemeral is one of four members of the genus Cardamine in Virginia. Cut-leaf Toothwort comes and goes quickly in early spring and depends on deep leaf litter for nourishment.
Sweet Cicely or Aniseroot (Osmorhiza claytonia or Osmorhiza longistylis) These two species of the genus Osmorhiza are prolific, but don’t mistake them for the invasive and slightly similar (at a glance) Garlic Mustard.
Rattlesnake Weed (Hieracium venosum) Identified in nearly every county in Virginia (including those with rattlesnakes) Rattlesnake Weed absolutely will not bite, but may surprise you with its bold leaves and spindly bright yellow flower high above. Look for it on edges that have a bit of sun.
Jewelweed (impatiens capensis) Jewelweed is in its early stages of emergence in drainages, swampy areas, and streamsides in our area; the showy, pollinator-magnet flowers that give it its common name will appear later in the season. Jewelweed has lots of fans among invasive plant warriors because of its ability to stand up to habitat destroyers like Japanese stiltgrass.
Poverty Oatgrass (Danthonia spicata) Our region is home to many native grasses, sedges, and rushes that (like all native plants) perform crucial ecosystem services where turfgrass does . . . almost nothing (when it comes to slowing and filtering stormwater runoff, a lawn performs not much better than pavement). Poverty Oatgrass prefers drier conditions, but is otherwise not picky. And Curly Grass (as it’s also called) is the host plant to the caterpillars of the Indian Skipper butterflies.
Striped wintergreen (Chimaphila maculata) Don’t be surprised if you spot this tiny evergreen in the vicinity of much taller neighbors, the American holly (Ilex Americana). Both occur in acidic soils. Bloom time is still ahead of us, so keep an eye out for the nodding, creamy white flowers late in spring and summer. Find out the meaning of its Latin name and explore the world of the very small in this blog post on The Natural Web.
Pinxterbloom Azalea (Rhododendron periclymenoides) We landscape with cultivars, but can they really hold a candle to Virginia’s native azaleas, of which Pinxterbloom is just one of seven? Certainly not when it comes to sustaining life; those seven species host the caterpillar larvae of at least 50 native butterfly species. The Virginia Native Plant Society blog currently features the Pinxterbloom for good reason.
This is just a handful of the locally native plant species you may be seeing in your neighborhood and in our parks now and year-round. If you’re lucky enough to have them right at home, keep up the good work of nurturing nature!
With Richmond, like the rest of Virginia, under a public health emergency Executive Order to “remain at their place of residence”, we’re all getting better acquainted with the places we call home. Fortunately, staying at home doesn’t mean staying inside. And tackling invasive plants is a great way to nurture nature and yourself:
Even the smallest yard likely harbors invasive plants, so read on for identification and management guidance on a few of the JRPS Invasive Plant Task Force’s “least wanted”, all Virginia state-listed invasive species:
These Vines are Not Fine
Truetimber’s own Mike Mather recently explained how to rescue your trees from the dangerous burden of English ivy, but other invasive vines may lurk in your yard:
As you may have read here, Fig Buttercup (Ficaria verna) is one of the most recent invaders of the park system threatening our indigenous spring ephemerals (wildflowers), but it isn’t spring’s only invasive target.
Don’t Hedge Your Bets – Get Rid of These Shrubs
The two most dominant invasive shrubs in the James River Park System are Amur Honeysuckle (Lonicera maackii) and Chinese Privet (Ligustrum sinense), both so abundant and successful at suppressing native flora that we see little else in the understory. They are ubiquitous in residential hedges and naturalized areas as well.
Next week we’ll shift to a more upbeat topic – native flora treasures hidden in plain sight!
FOR MORE INFORMATION
EDITOR’S NOTE: This article is the first in occasional series from members of the James River Park System Invasive Plant Task Force.
Some of the earliest signs of spring in Richmond are downright ominous for those who know how to read them. The pretty yellow flowers of Fig buttercup (Ficaria verna) are one of those unwelcome harbingers. If this early-blooming perennial has popped up in your yard, you will want to take action to prevent its spread into our urban woodlands, including the James River Park System.
Fig buttercup (also commonly known as “Lesser Celandine”) is an invasive plant introduced from Europe. The USDA ranks it as a high-risk weed and several states have banned its sale. Like all invasive plants, it is highly successful at aggressively reproducing and spreading, wiping out our diverse, indigenous native plants, particularly spring wildflowers like bloodroot, spring beauty, and trout lily. The James River Park System Invasive Plant Task Force, with grant-funded professional assistance is currently treating Fig buttercup invasions in The Wetlands section of the park and needs your help to curb the spread.
Some identifying features of Fig buttercup:
Its stems and leaves emerge as “basal rosettes” in late winter.
It resembles common buttercup and has shiny, dark green, heart-shaped leaves with netted veins on their undersides. Yellow flowers have varying numbers of petals. You can find a detailed guide to identification here.
Ficaria verna favors full sun and riparian zones (areas adjacent to rivers, streams, lakes,
and ponds) but also thrives in shady woods and lawns.
It forms vast, solid mats that choke out native flowers, grasses, and shrub and tree seedlings.
After blooming, the above-ground plants quickly disappear by late May or early June.
It reproduces and spreads through multiple means, primarily underground tubers and bulblets.
Richmonders have an opportunity with Fig buttercup that we didn’t have with many other now dominant invasive plants like English ivy: we can check its spread and protect our park system’s urban forest and the native plant communities that struggle to survive in the midst of an overwhelming abundance of invasive plants (there are approximately 50 identified invasive plant species throughout the JRPS and they are the dominant vegetation in much of it).
Ficaria verna is far trickier to manage than vines like ivy or shrubs like privet. The treatment window is short, and management must occur in late winter or early spring. Well-intentioned removal attempts can instead contribute to its spread. Hand-digging scattered, individual plants is possible, but must be done carefully to ensure removal of all underground parts of the plant.
Treat these like toxic waste: securely bag and place in the garbage. Large infestations require the judicious use of a wetlands-approved herbicide; treatment must occur soon after the plants emerge, never late in the flowering period because of risks to native plants and amphibians, and according to specific weather conditions. Only trained applicators should undertake this work and should strictly follow the prescribed treatment for Fig buttercup. The Upstate Chapter of the South Carolina Native Plant Society and Virginia’s own Blue Ridge PRISM both provide excellent guidance.
If you would like more information about the impact of invasive plants on our park system, please visit the JRPS Invasive Plant Task Force website.