Looking Back, Looking Forward: Fraxinus spp. and the Emerald Ash Borer

May 27, 2020 · 4 minute read
Looking Back, Looking Forward: Fraxinus spp. and the Emerald Ash Borer

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.  

“The compoundly pinnate leaf structure of Fraxinus”

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 compoundly pinnate leaf structure of Fraxinus

The survivors

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.

Characteristic “blonding” on a green ash tree.

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.

Native Shrubs and Perennials for Your Yard or Garden

May 13, 2020 · 2 minute read
Native Shrubs and Perennials for Your Yard or Garden

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

Green and Gold (Chrysogonum virginianum)

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.

Golden-alexanders

Golden-alexanders (Zizia aurea)

Delicate and bright, Golden-alexanders prefer moist soil. Butterfly bonus: This is the host species to the Black Swallowtail.

Golden Ragwort (Packera aurea)

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.

Eastern Blue-star

Eastern Blue-star (Amsonia tabernaemontana)

Seen here just before blooming, Blue-star is truly at home in Richmond, though it occurs infrequently in its limited range.

Woodland phlox

Woodland Phlox (Phlox divaricata)

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

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.

Arrow-wood

Arrow-wood (Viburnum dentatum)

All viburnums are “wildlife powerhouses,” their flowers feed native bees and other pollinators, while their berries are forage for songbirds.

Virginia sweetspire

Virginia Sweetspire (Itea virginica)

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.

Ninebark

Ninebark (Physocarpus opulifolius)

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.  

Rosebay rhododendron

Rosebay Rhododendron (Rhododendron catawbiense roseum)  

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

May You Bloom and Grow: Native Plant Species to Notice Now

April 28, 2020 · 3 minute read
May You Bloom and Grow: Native Plant Species to Notice Now

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: 

The “apple” of the Mayapple. Credit: Catherine Farmer

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”.

The distinctive Mayapple.

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.

Cut-leaf toothwort. Credit: Catherine Farmer

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.

Sweet Cicely or Aniseroot. Credit: Catherine Farmer

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.

Rattlesnake Weed
Rattlesnake weed in bloom

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.

Jewelweed

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.

Poverty Oatgrass

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.

Striped Wintergreen.

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. 

Pinxterbloom Azalea is Forest Hill Park. Credit: Stan McCulloch

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!

Home Is Also Where the Invasives Are

April 9, 2020 · 3 minute read
Home Is Also Where the Invasives Are

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:

  • It’s a satisfying stress reliever; your brain gets a rest while your body gets a workout, and you are rewarded with measurable results.
  • Controlling invasive plants is essential for a more ecologically healthy yard; if you want your home to be habitat for more than just you and your family, this is step one.
  • You’ll earn the right to dream and plan . . . about planting locally native plants in the fall.
  • You’ll be helping out our park system even while the Task Force has to suspend public volunteer events. Making progress in the park means slowing the spread from outside of it.

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:

Perwinkle (Vinca major, minor)
  • Winter Creeper (Euonymous fortunei) hangs out with English ivy and behaves just as badly; the two dominate in the James River Park System, threatening our city’s tree canopy and carpeting once rich woodlands.  Free your trees and pull the ground cover, getting out all the roots as much as possible.
  • Japanese Honeysuckle (Lonicera japonica) is the most widespread invasive vine in the eastern United States, smothering native vegetation and girdling to death tree and shrub saplings.  Locating and pulling the rooting nodes of this invasive is uniquely satisfying.
  • And while you’re at it . . . reconsider that Periwinkle (Vinca major, minor). This still popular landscaping vine is also invasive.

Herbaceous Horrors

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.  

Garlic mustard in bloom.
  • Garlic Mustard (Alliaria petiolata), another park invader you may find at home, is easier to remove because it’s a ‘herbaceous forb’, not a vine or woody stemmed plant. Garlic Mustard displaces native spring wildflowers and is toxic to the larvae of our butterfly species whose host plants are natives in the Mustard family.
  • This biennial species takes two years to mature; first-year plants are low “rosettes” with kidney shaped, scalloped leaves that become more heart-shaped in their second year when the plant flowers and seeds. Pull these plants, getting the entire tap root, prior to flowering and setting seed. Bag and dispose of any plants that already have flowered. The ideal window for removing Garlic Mustard in our area has just closed, so use caution. For detailed identification and instructions, see this action alert from Blue Ridge PRISM.

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.

Amur honeysuckle
  • Amur Honeysuckle Don’t be lured by its fragrant blossoms and associated childhood nostalgia — Amur Honeysuckle is a habitat destroyer. Its dense thickets leaf out in February, shading out native vegetation; it is “allelopathic”, generating its own chemical that, depending on soil conditions, acts as herbicide for many native plants; and its berries are the equivalent of junk food, inadequate nourishment for songbirds in need of their native plant food sources.
  • Chinese Privet  The worst of numerous invasive privet species, Chinese Privet has a lot in common with Amur honeysuckle – a multi-strategy habitat destroyer.
  • New seedlings and smaller, young plants of both are easy to pull up with your hands. Repeatedly cutting back larger shrubs prevents their reproduction and spread. Follow the embedded links above for more control and removal guidance.
Japanese honeysuckle and winter creeper (and some determined native ferns)

Next week we’ll shift to a more upbeat topic – native flora treasures hidden in plain sight!

FOR MORE INFORMATION

Plant RVA Natives

Virginia Department of Conservation and Recreation’s Natural Heritage Program

Plant Invaders of Mid-Atlantic Natural Areas (National Park Service)

Spring’s Worst Invasive Plant Threat: Fig Buttercup

March 23, 2020 · 2 minute read
Spring’s Worst Invasive Plant Threat: Fig Buttercup

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 forms a thick mat and crowds out native species.

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.