ARMN Ozone Bio-indicator Garden: Report From the 2022 Growing Season

by Leslie Cameron

The ozone bio-indicator garden at the Walter Reed Community Center (WRCC) is concluding its second full growing season. Arlington Regional Master Naturalists installed the garden in 2020 and are collecting data on the impact of tropospheric or ground level-ozone air pollution on plants, in cooperation with NASA, the Harvard Smithsonian Center for Astrophysics Science Education, and Arlington County. The garden is part of the international Ozone Bioindicator Garden Network, organized in part by the National Center for Atmospheric Research (NCAR) in Boulder, CO. There are 17 ozone gardens across 12 states. Data on the impact of ozone on plants from this garden are uploaded and merged with data from other gardens in the network. 

After its launch into space, anticipated in January 2023, an instrument called TEMPO (Tropospheric Emissions: Monitoring Pollution) will begin taking measurements of major air pollutants, including ozone, across North America. Data from the network gardens will be coordinated with air pollution data from TEMPO. For more background on this project, see earlier blog articles about the mission and installation of the garden (February 2021), and a report on the first full growing season in 2021 (November 2021). 

In 2022, ARMN members Barbara Hoffheins, Todd Minners, Jon Bell, Anne Doll, and Ruth Lane planted, maintained, and monitored the plants for ozone damage.

Other goals were to create signs with a QR code for more information and signs in English and Spanish to educate visitors about air pollution in Arlington and how to reduce ozone levels. 

Photo of a sign that says Ozone Bioindicator Gardne with logos from the Smithsonian, NASA, and ARMN
The QR code on the garden sign links visitors to more information about the project. Photo by Leslie Cameron.

The Smithsonian Astro Observatory supplies all the seeds for this garden. The 2022 garden includes the same varieties of sensitive and tolerant snap beans, sensitive and tolerant tobacco, sensitive potato, and sensitive Common Milkweed (Asclepias syriaca) as were in the 2021 garden. Sensitive Cutleaf Coneflower (Rudbeckia lacianata) was seeded in fall 2021 and added to the garden for the 2022 growing season.

Photo of a volunteer standing to the left of the Ozone Bio
ARMN member Barbara Hoffheins takes a break from working at the garden. Photo by Jon Bell in May 2022.
Photo of a volunteer pointing to a milkweed plant in the garden bed.
This bed includes sensitive beans on the right and tolerant beans on the left in the rear, and milkweed in front. Photo by Jon Bell in May 2022.
Photo of a garden bed with a sign in front
This bed includes sensitive potatoes on the right and tolerant potatoes on the left. Photo by Jon Bell in May 2022.

Ozone causes stippling or purpling on the top sides of leaves (usually not undersides), and inside, not crossing the veins, and it usually affects older leaves (not younger).  Damage from other causes may look like ozone. The first photo (below) shows what ozone damage looks like. The second photo shows damage that is not from ozone. 

Ground-level ozone is more likely to reach unhealthy levels on hot sunny days, and ozone damage to plants is more likely in late summer. In this garden, ozone damage is likely to be more noticeable on second- and third-year perennials. 

Beginning in March, garden volunteers regularly tracked planting, watering, weeding, and other maintenance completed, as well as weather (via NOAA observations for Washington/Reagan National Airport) and ozone levels (via the Virginia Department of Environmental Quality). No damage to plants from ground-level ozone was observed in 2022. These observations were confirmed by outside experts from Howard University and NCAR. The data from these observations will be uploaded to the Ozone Bioindicator Garden Network database in the fall.

Graph which shows Ozone Expsoure Trends in Aurora Hills from M
Ozone trends between May 1, and July 20, 2022, at the Aurora Hills sensor. An NCAR expert confirmed that the levels of ozone from the Aurora Hills sensor did not appear to be high enough or of long enough duration to cause damage. Neither the air monitoring station nor the garden is located near heavy transportation exhaust, which is the leading cause of air pollution in our area.

Readings were also compared to a ground-level ozone sensor in the Arlington’s Aurora Hills neighborhood. Ozone levels vary from area to area and ozone can be blown around by the wind, so a sensor in a nearby area like Aurora Hills will not necessarily measure the same level of ozone as at the garden at the Walter Reed Community Center, about a mile away. However, a reading nearby may be a useful guide. The NCAR expert said that the reported levels of ozone from the Aurora Hills sensor did not appear to be high enough or of long enough duration to cause damage. For more on identifying ozone damage, see

Other takeaways from the garden in 2022:  Based on recommendations from a Howard University atmospheric science professor, the 2022 garden was partially replanted more sparsely to make cataloguing damage easier. The ARMN members maintaining the garden grappled with damage from the usual garden pests—rabbits and possibly other mammals. This will likely remain a challenge in 2023. Seed potatoes saved from 2021 were used to plant in 2022, and this year’s crop is large enough to share with other network gardens as this potato variety is not sold commercially and it is highly valued for ozone research. An idea for next year would be to ask the Aurora Hills community garden staff if they would be willing to plant tolerant and sensitive snap beans and potatoes in their garden to compare with the plants in the WRCC garden. These plants have been good producers, taste good, and they could serve two purposes—one for science and the other for food production.

Reducing air pollution and keeping the air cleaner will benefit all of us. For tips on steps we can take, see AirNow.  

The Ozone Bio-indicator Garden is located at the Walter Reed Community Center (2909 16th St. S., Arlington, VA), in front of the building on the west side.  Visitors are always welcome!

Arlington County Fair: Candy Worms, Native Plants, and a “Spotted Lanternfly” Make a Fun Event for Visitors and Master Naturalists Alike

Text and photos by Marj Signer 

More than two dozen ARMN members shared their love of nature with numerous visitors at the Arlington County Fair, August 19-21 at the Thomas Jefferson Community Center. The ARMN exhibit space provided an opportunity for members of the public to learn about their master naturalist neighbors’ passion about nature. While many were interested in information about the imbalance and destruction caused by deer and the pilot project to eradicate the highly invasive Japanese stiltgrass (Microstegium vimineum), the greatest interest was in native plants. Most people were well-informed about our natives, indicating perhaps that the combined outreach efforts of the environmental community are making an impact.    

Our display was set in front of a three-panel backboard that told that basic facts of ARMN—we’re volunteer educators, citizen scientists, and stewards helping Virginians conserve and manage natural resources and public lands. Folks gathered in front of our table to enjoy the offerings, exchange stories, and talk about problems and tips. 

Photo of a volunteer standing in front of a display table speaking to two children.
Jack Person helps young visitors estimate the number of gummy worms in the jar.

The main attraction was a gummy worm guessing game, organized by Master Naturalist Susan Berry. The jar of candy worms attracted children of all ages and their families and friends. While kids pondered the question of “how many worms are in the jar?” we talked about the importance of caterpillars in the cycle of nature. (The gummy worms represented caterpillars.) For the record, there were 175 gummy worms in the jar. Guesses ranged from 50 to a thousand. 

The serious lesson of the game was that lots of caterpillars, characterized by these candy worms, are essential to the maturing of baby birds. The worms in the jar represented one-third of the approximate number of caterpillars that a clutch of baby chickadees needs to eat every single day to mature and be ready to fledge. Some of our younger visitors were impressed to know that the container held just lunch or breakfast for one day. A clutch of chickadees, for example, needs somewhere between 6,000 and 9,000 caterpillars to be ready to fly. Mama and papa chickadee work from about 6 am to 8 pm all day to bring three gummy worm jars’ worth of caterpillars to the nest of baby birds, and they do that every day for 16 to 18 days.

Two volunteers stand in front of a display table with plants and posters and speak to four listeners.
Fair visitors are captivated by Master Naturalist Diane Goebes’ explanation of caterpillars as bird nourishment, with fellow MNs Rebecca Halbe and Doug Brown on hand for questions.

The gummy worms were the perfect entrée for talking about native plants as the best source of food for the baby birds. Master Naturalist Stephanie Martin commented: “I think at least some of the children and most of the parents got the message that we need native plants to host all those caterpillars for the birds.” Scientific research backs that up. According to the PennStateExtension website article, “A Case for Caterpillars,” “Many butterfly and moth caterpillars have coevolved with plants. Coevolution involves reciprocity—which means that an evolutionary change occurs between pairs of species as they interact with one another. That is to say that many caterpillars have evolved to be solely dependent on certain habitats and even a genera or species of plant.” In short, native plants are basic to the natural cycle of life!

Stephanie added: “Many of the extended conversations I had were with people who were already quite well-informed about the benefits of native plants. For example, I commiserated with one lady about the need to constantly pull English ivy year after year. People were interested in learning more about native alternatives. I directed quite a few to the Plant NOVA Natives website” ( That website has a wealth of information about the importance of natives, the harm caused by exotic invasive plants like English ivy (Hedera helix), and a lot more for individuals and landscape professionals, including good choices of native plants for particular situations.

A display of native seed packets and plant cuttings was another attraction. The seeds were gathered from the pollinator garden, next to the PTA’s vegetable garden on the Thomas Jefferson Middle School grounds, literally around the corner from the fair. We had seeds from three species of native plants growing in that garden that attract pollinators: common milkweed (Asclepias syriaca), New York ironweed (Vernonia noveborecensis) and Joe-Pye weed (Eutrochium spp.). We also had cuttings of all three on the table and a map of the garden so folks could visit “the real thing” if they were interested. Master Naturalist Amy Spector chatted with a young woman and her family about the seed packets. Showing the cuttings of each specimen, she pointed out that all three common names end with weed: milkweed, ironweed, Joe-Pye weed. They considered why this was so and narrowed it down to two possibilities. Either these plants are so prolific, sprouting up in unlikely spots, that people mistake them for undesirables, or they “grow like a weed.” It’s likely that these native “weeds” are just good spreaders, and just may need a bit of thinning sometimes. 

A volunteer stands in front of a table with pamphlets. She is engaged in coversation.
Mary McCutcheon, Master Naturalist and Park Steward at Fort Bennett Park, addresses the importance of removing English ivy from trees.

We also displayed cuttings of the invasive porcelain berry plant (Ampelopsis brevipedunculata) with the note: “bad weed.” Lively conversations sprouted up about how confusing it could be to tell porcelain berry from native grapevines (Vitis spp.) and the trials and tribulations of keeping weeds under control. Mary McCutcheon, Park Steward at Fort Bennett Park, shared her experience using a small “barbie saw” to cut down English ivy. A man from a north Arlington neighborhood told another story of saving trees from the grip of ivy. He removed an ivy infestation year after year until it was gone. This, he said, was his post-retirement contribution to community well-being and his way of keeping in shape.

Several visitors who lived in apartments and condos without personal yard space were interested in ways they could garden. Master Naturalist Colt Gregory explained that they could plant natives in a pot on a balcony or other such space and he gave them some of the seeds to try it out. “I think the seed packs were a great hand-out idea,” he said. “Folks were also interested in plant lists.”  We had two brochures on easy-to-grow native plants—one on plants for sun and one on plants for shade—that were so popular that our stock was depleted well before Saturday evening. You can see these brochures and others at:

A young woman who lives in a condominium community stopped by the ARMN table for assistance in explaining the value of native plants to her neighbors. She insisted on making a donation for two copies of the beautifully illustrated booklet: “Native Plants for Northern Virginia.” She felt the booklet offered the guidance she needed to convince her community about landscaping with native plants. The excitement and appreciation she showed for native plants was a joy. 

A volunteer hands a pamphlet to a condo resident who is looking at a book.
Master Naturalist Heidi Moyer, (left) talks with Allison, a condo resident, about landscaping with natives on condo properties.

We also had a nest of a bald-faced hornet (Dolichovespula maculata) that Master Naturalist Gary Shinners brought in. Colt Gregory observed that the visitors didn’t think it was real and quickly poked their fingers through the papery material. Colt explained that each little cell inside the nest—which was now torn open—held eggs for baby hornets. “When I looked in myself, it really is amazing how many little octagon cells are inside a hornet’s nest,” he said.

A woman wearing a spotted lantern fly cosutme spreads her wings.
Kirsten Conrad, the Agricultural Natural Resources Extension Agent for Arlington County, flitted around as the destructive spotted lanternfly.

The ARMN display table was part of the Virginia Cooperative Extension Service group and placed between the Tree Stewards of Arlington and Alexandria and the Master Gardeners of Northern Virginia and near the Arlington Friends of Urban Agriculture. It was a lively section of the fair, with lots of visitors and some special and unanticipated attractions. Kirsten Conrad, the Agriculture Natural Resources Extension Agent for Arlington County and the City of Alexandria, donned a spotted lanternfly (Lycorma delicatula) costume to be sure we all remembered the danger posed by this invader. These insects, which are a federally regulated invasive pest, are spreading at an alarming rate, eating the sap of trees—including oaks and walnuts—as well as grapes, hops, vegetable plants, and herbs, among other plants in their path. Kirsten gave us a memorable performance of this destructive plant assailant, flitting throughout the area.

Susan Kalish, Director of Public Relations for the Arlington County Parks and Recreation Department, also made a definite impression on kids and at least one adult (the writer of this blog) with her handling of a black rat snake (Pantherophis obsoletus) who lives at Long Branch Nature Center.

A volunteer in a green shirt holds a black snake that is curled around her hand.
Susan Kalish, Director of Public Relations for the Arlington County Parks and Recreation Department, introduced a black rat snake, aka Eastern rat snake, to Fairgoers.

Susan Berry reported that the best comment of the weekend, in her opinion, was made by a pleasant lady who was captivated by the discussion of the reliance of one species on another. She commented: “This is the best thing I have done all day, other than that Chardonnay-Frappe thingy I had outside.”

Nature is wonderful! 

Catch that “Running Bamboo” in Fairfax County or Risk a Fine!

By Elaine Kolish

During the dog days of summer, it may be difficult to look ahead to January. But for property owners and tenants in Fairfax County with “running bamboo” in their yards, January 1, 2023, is an important date to mark now. On that date, a Fairfax County Bamboo Ordinance goes into effect to help homeowners suffering from incursions of bamboo from their neighbors’ properties. Fairfax County adopted this ordinance after the Virginia state legislature (like some other states in the North East) passed a law in 2018 designating running bamboo as a “noxious weed” and allowing localities to provide for control of it (Section 15.2-901.1 of the Code of Virginia). No other Northern Virginia jurisdictions, besides Fairfax, have such ordinances at this time. [Editor’s note:] After this piece was posted, we learned from Petra Riedel-Willems that there are two other counties in Northern Virginia—Fauquier and Stafford—with bamboo restrictions that predate the Fairfax ordinance. We appreciate the comment from Ms. Riedel-Willems that is posted below this article. And we believe that this information is valuable for others who may want to deal with running bamboo in their own yards or communities.

The Fairfax County ordinance says that bamboo owners, whether or not they planted the bamboo, must not allow bamboo to spread from their yards to any public-right-of-way or any adjoining property. While maintaining bamboo on one’s own property is legal, it is illegal to allow bamboo to spread beyond your property’s boundaries. Taking action now rather than waiting for a complaint to be filed against you is something to consider.

This ordinance was adopted because running bamboo (distinct from clumping bamboo to which the ordinance does not apply) is a destructive, fast-growing grass. Its horizontal rhizomes spread underground as much as 15 feet per year. Its roots can go through brickwork, patios, and weak spots in concrete. It also suppresses native plant species that are beneficial for our environment. 

Running bamboo’s aggressive growth habit makes it difficult to remove and a sustained, multi-year effort may be necessary. A Fairfax County publication, “Running Bamboo,” recommends three containment/control methods: root barrier, removal, and cutting and herbicide application. The containment method involves installing vertical root barriers 30 inches below ground and six inches above to deflect rhizomes so they go towards the owner’s property and making the rhizomes visible at the barrier. Strong materials, such as metal or high-density plastic, should be used for the barrier. Alternatively, a homeowner might wish to control their bamboo by removing it completely. 

A fellow ARMN member whose bamboo created a visual block between their property and a neighbor decided to encircle a section of bamboo between the properties with a cement wall one foot wide and two and a half feet deep. The wall has worked well to contain the bamboo since its installation in 2008.

Photo of a patch of bamboo growing up to a curving cement curb.
Two and a half by one foot cement bamboo barrier that has contained bamboo effectively for fourteen years. Photo courtesy of Kasha Helget.

Digging bamboo out may require heavy equipment for larger groves and in that case should be addressed under Virginia 811 rules ( See the “Running Bamboo” publication noted above for additional information.

All cut bamboo and roots must be disposed of in the TRASH, not in a compost pile or bin for lawn debris under the Fairfax County requirements. If you want to dry the culms or canes for another use, such as stakes or crafts, do not do so on top of the soil, which will risk it taking root.

The Fairfax County Department of Code Compliance is responsible for enforcing the ordinance based on complaints it receives. After a Notice of Violation has been issued, each day that running bamboo remains unconfined may result in a fine of $50, up to a maximum of $2,000 in a 12-month period. The number to file a complaint is 703-324-1300 or file online at

Don’t wait. Catch that running bamboo now. This is good advice for Fairfax County residents and anyone else who has running bamboo on their properties!

For more information visit: Fairfax County Bamboo and

Arlington’s Native Plant Nursery Restores Our Area’s Native Flora

Text and photos by Leslie Cameron. (Photos were taken on a July 12, 2022 workday unless otherwise noted.)

Historically, Arlington County is home to 28% of the native plant species in Virginia—representing substantial plant diversity in the county’s 26 square miles. Unfortunately, Arlington has lost an estimated 200 of these native plant species. Though 600 native plant species are still found here, many exist in small numbers or are considered locally rare.

Under the direction of Alonso Abugattas, Arlington’s Natural Resources Manager, and Jennifer Soles, Natural Resource Specialist, Arlington’s Native Plant Nursery helps to restore native plant species by propagating native trees, shrubs, and other plants for transplanting into Arlington’s parks and other public spaces. Since the Native Plant Nursery was established in 2014, it has enabled the installation of more than 10,000 native plants. 

Two volunteers look down at rows of plants. A third person is gesturing with hands.
Student volunteers working with Alonso Abugattas.

The Nursery propagates local-ecotype native plants and specializes in meadow species, locally rare plants, and native species that historically grew in Arlington but are no longer present. Plants from the nursery are also used in forested areas that have been cleared of non-native invasive plants.

Photo of a plant in a pot. The plant has four leaves and is a purplish green.
Starry Campion (Silene stellata) is a native wildflower no longer common in Arlington that was propagated from plants identified as local-eco-types. (Photo taken in Fall 2021.)
A volnteer
Volunteer sorting the garden gloves.

ARMN members regularly volunteer at the Native Plant Nursery, along with other community volunteers, working to contribute to Arlington’s restoration efforts. 

Volunteers mix and move soil and pot up seedlings. They add rice hulls, which are organic and sustainable, to pots as a mulch to retain moisture and also weed the potted plants on the ground.

Two people crouch in front of rows of plants.
Alonso Abugattas working with one of the volunteers.
A photo showing the native plant nursery. Rows of plants are beneath a shade screen.
Overview of the Native Plant Nursery.

An irrigation system keeps growing plants watered, and an overhead screen protects young plants during the hottest days. Plants spend an additional growing season in the nursery before being transplanted. 

On this workday in July, volunteers helped to pot seedlings and label plants. It turns out the crows pick out the plant labels and toss them around, so volunteers are creating new labels to affix to stakes and pots more securely. 

Volunteer wor
Volunteer creating new plant labels.
Photo of a volunteer planting grasses into pots.
Volunteer potting up Path Rush (Juncus tenuis) seedlings.

Seedlings potted up on this workday include White Cut Grass (Leersia virginica), a native grass that tolerates shade, and Path Rush (Juncus tenuis), which grows to around 2 feet and tolerates full sun to part shade, as well as some mowing and foot traffic. Arlington County plants Path Rush along the paths and trails through county parks where it does very well.

Later, plants will overwinter in the nursery or in the greenhouse nearby, where volunteer work continues into December.

Photo of native plants in the nursery. The leaves are starting to change into fall colors.
The row of “woodies” is changing colors. (Photo taken in Fall 2021.)

The Native Plant Nursery, located behind the ballfield at the corner of S. George Mason Drive and Four Mile Run Drive, is also where residents can pick up one of the free native trees provided by the county. Registration for a free tree opens September 6, 2022. For more information, see

For additional details about the Native Plant Nursery and volunteer to help care for it, see:

For more on the native flora in this region and many other wonders of the natural world, follow the Capital Naturalist blog by Alonso Abugattas at

Getting to Know You: Three Extraordinary Members of ARMN’s Fall 2021 Class!

By Elaine Kolish

After a bit of a hiatus in our GTKY series, we’re introducing you to three more individuals in our ARMN family. Let me present Tina Dudley, Dan Huddleston, and Elise Milstein, who completed their Master Naturalist training AND certification requirements in Fall 2021. According to Janet Siddle, ARMN Training Coordinator, “it is not unprecedented for a trainee to do both, but it is far from common!” I thought it was worth getting to know these overachieving classmates of mine a bit more, including how they managed to complete 40 service hours and eight continuing education hours while taking fourteen weekly classes, attending four day-long Saturday field trips, doing our homework, completing quizzes, and preparing and making a five-minute presentation to our class. They’re not resting either, as we’ll see from the kinds of volunteer projects on which they’re working now. 

None of us in the class can forget Tina’s presentation on the wonderful but little regarded possum, Elise’s impassioned lecture (in costume) about the dangers of ticks, and Dan’s presentation of his stunning wildlife photos. 

Although their careers have differed, nature is a common thread running through each of their lives. For a long time, they have been involved in an amazing array of outdoor volunteer activities. Besides ARMN, Tina participates in the Northern Virginia Birding Club and the Virginia Herpetological Society. She also enjoys writing a blog about animals: Dan does lots of different kinds of volunteer work, but outdoor volunteerism, such as for the C&O Canal  and blue bird monitoring programs, has become increasingly important to him and for the last ten years he has focused on being a wildlife and nature photographer. Elise is a member of the Potomac Appalachian Trail Club  and the Audubon Naturalist Society. She also is a board member with the Friends of Theodore Roosevelt Island and leads tours on the island for the National Park Service.

So how did these already busy people manage to get all their hours in while training? Tina says, “I was between jobs so had more time.” Well, other classmates and I who are retired and don’t have jobs didn’t manage this feat. So, there’s more to this story. Grit, determination, and an overwhelming passion for nature played big roles here!

Photo of a volunteer standing in front of greenery holding a snake.
Tina Dudley holding a smooth green snake (Opheodrys vernalis). Photo by Emerson Milam.

Tina, a Goucher College women’s studies major, now lives in Reston, and works at the Audubon Society of Northern Virginia. Like Dan and Elise, Tina has tried out a variety of ARMN projects (invasive plant removals and interpretive events) and found she really loves caring for the reptiles at Potomac Overlook Regional Park and talking to the nature center guests, especially kids, about them. She is looking forward to teaching people about snakes in the future.

Dan graduated from Texas A&M University with a degree in Environmental Design but has lived in Northern Virginia for 56 years. Dan, like Tina, has sought variety for his service hours but he has chosen to volunteer at several parks that either didn’t exist when he was growing up or that he never had had an opportunity to visit. He has enjoyed learning what each park has to offer with their unique histories and qualities. He finds working in the soil with plants very restorative and a pleasant change after working in a rat race. Ultimately, he decided to make the Buddie Ford Nature Center in Alexandria the focus of his activities. There is small cohesive group there and lots to do! They are lucky to have found a true buddy in him.

Photo of two volunteers. One is wat
Dan Huddleston in action during a Buddie Ford Pollinator Garden wall installation as fellow Master Naturalist Hal Cardwell looks on. Photo by Devin Reese.
Photo of a volunteer who is smiling.
Elise Milstein attending the July ARMN Chapter meeting. Photo by Elaine Kolish.

Elise grew up exploring Gulf Branch, Pimmit Run, and Great Falls, and currently lives in Arlington. With degrees in law, sociology, and public administration, her work managing legal and IT projects keeps her indoors and is often fast-paced and high-pressure. As an antidote, Elise escapes into nature for its mental health benefits. Like her colleagues, Elise has been sampling projects, like invasive plant removal, and chapter support. She enjoys birding and as an ARMN citizen science project, she has spent many hours reporting her findings on eBird. On her outings, besides noting many species of birds, she has met the Ambassador of Switzerland and one of the creators of the iNaturalist nature app that helps you identify the plants and animals around you. Ultimately, she’d like to do more education and outreach with kids to spark their curiosity and encourage their love and protection of the natural world. She posts some of her nature photos on Instagram at: sporangelise.

While the whole Fall 2021 class is remarkable in many ways, I think you’d have to agree these classmates stand out and are an inspiration to us and future classes. Please give them a high five the next time you see them as they volunteer in the community!

ARMN Summer Chapter Meeting Highlights the Four Mile Run Conservancy Foundation and Mini Bioblitz

Text and photos by Rod Mackler, unless otherwise noted.

ARMN held its summer chapter meeting in Alexandria’s Four Mile Run Park.  The “Arlington Region” for the Arlington Regional Master Naturalists includes Alexandria, Falls Church City, and parts of Fairfax County, as well as Arlington County.  It was a glorious day, with temperatures in the 70s and sunny. The ARMN members were eager to learn about the Four Mile Run Conservancy Foundation and explore the park in a mini bioblitz.  

Photo of a group of volunteers listening to a speaker.
ARMN members listen to ARMN President, Phil Klingelhofer, during the summer chapter meeting. Photo by Todd Minners.

The host of the meeting was the  Four Mile Run Conservancy Foundation, headquartered in Del Ray. The Foundation focuses on the lower, tidal portion of the Four Mile Run stream on both shores, Alexandria and Arlington. 

Photo of a map of Four Mile Run watershed
Map of Four Mile Run Watershed at Four Mile Run Park.

Foundation president Kurt Moser introduced us to the Foundation’s work—restoration, advocacy, recreation, and education—then took us over to see its field station nearby. 

Photo of an office.
Four Mile Run Conservancy Foundation field station.

From the field station, the ARMN members launched a mini-bioblitz, dividing up into teams, looking for new (to us) plants and animals, and entering our finds in the iNaturalist app. iNaturalist is a network of naturalists, citizen scientists, and biologists, mapping and sharing observations of animal and plant biodiversity. iNaturalist includes millions of observations entered daily by some 350,000 users as an open-source platform and data base for scientists, land managers, naturalists, citizen scientists, and the members of the public at large.

Four Mile Run Park was a rich source of findings for the bioblitz, with its meadows, wetlands, and woods. We found and uploaded a wide range of native plants, and quite a few invasive plant species, as well. These baddies included bush honeysuckle (Lonicera spp.), tree of heaven (Ailanthus altissima), purple loosestrife (Lithium salicaria), and porcelain berry (Ampelopsis glandulosa). Observations of invasives are a particularly useful contribution of citizen scientists, giving a good indication of their range and spread. Most of our observations were the plants in the park, but also included a few local animals: fireflies (family Lampyridae), a green heron (Butorides virescens), and an osprey (Pandion haliaetus)

Anyone can download the free iNaturalist app to become a part of this worldwide citizen scientist community. Happy hunting!

Stemming Erosion and Shoring Up a Learning Space in the Jerome Buddie Ford Nature Center Pollinator Garden

Text and photos by Devin Reese 

Two volunteers work on building a brick colored wall
The nearly complete retaining wall brings a smile to the face of Master Naturalist Adam Vogel (right).

Explains Master Naturalist Valerie LaTortue who stewards the Pollinator Garden at the Jerome Buddie Ford Nature Center, “Today, we are working on a teaching area and rainwater garden. When it rains hard, water pours off the roof, and the flow moves everything downhill.” Valerie has organized a volunteer crew to work in the Pollinator Garden most Saturdays. To maintain its allure for pollinating insects, the garden requires ongoing removal of invasives to allow native species like milkweeds (Asclepias spp.) and coneflowers (Echinacea spp.) to thrive. (See July 31, 2021 blog piece, “Revitalizing the Pollinator Garden at the Buddie Ford Nature Center.”

But on this Saturday, I have joined the crew of volunteers with the task of building a short, curved retaining wall to make a barrier against erosion as well as demarcate a small area for visitors and students to stand while viewing the garden. Master Naturalist Dan Huddleston leads the project, bringing his skills as a former construction manager for the State Department to this exponentially smaller job. Dan directs us to get shovels and heavy bags of materials. And then the work begins. 

There are more volunteers than there are shovels, and one high schooler earns service hours from the City of Alexandria for the National Science Honors Society by pitching in on whatever project is going on at Buddie Ford during her volunteer days. As she digs out part of the trench for the wall and then later removes weeds from around a PawPaw (Asimina triloba) tree, she says she is considering going into ecology as a career. 

Master Naturalist trainee Jennifer Piatt (right) and Volunteer Andy work together on preparing the erosion control cloth that will serve as wall underlayer to catch any materials moving downslope.

Volunteer Andy confesses that he’s a first-time volunteer, having trailed his girlfriend—2022 Volunteer Basic Trainee, Jennifer Piatt—to the event. Andy does a lion’s share of digging despite his self-description as an “ad hoc helper.” A special agent with the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF). Andy lives in a D.C. condo and has little chance to get his hands in the dirt (at least actual dirt!) in his regular life. Andy says, chuckling, that he “heard all about the ARMN class online over dinner” during his girlfriend’s training. Whether he will one day get certified as an ARMN volunteer remains to be seen, but he’s happy to be a tagalong for now. 

Valerie LaTortue is a magnet for volunteers. Her own son, Mohammed, a mechanical engineering student at Northern Virginia Community College (NOVA), pitches in with other volunteers. Mohammed dreams of one day designing high performance cars at his own automobile company. In the meantime, it’s clearly not the first time Mohammed has lent a hand to get the Pollinator Garden in shape. He describes his weeding and planting work from previous Saturdays as ways he is “helping my Mom.”

Photo of two volunteers digging with shovels
Volunteer Mohammed (right) wields a shovel next to Master Naturalist Adam Vogel.

As the digging winds down, we line the trench with the erosion control cloth, then top it with a thin layer of drainage rocks scooped from heavy bags. Volunteer crew members check the trench with I-beam levels to make sure the wall will end up horizontal. 

Photo of a volunteer checking the ground with a level
Adam checks the trench to make sure the wall will end up horizontal.

Andy: “Mohammed, that’s right on. Yours is the only good one that’s really level.”

Mohammed: “A bee landed on you, Andy.”

Andy: “That’s OK, I’m not a flower. It won’t bother me.”

Master Naturalist Hal Cardwell: “You learned that in your ARMN class, didn’t you?!”

Mohammed (top) and Dan make sure everything is level.

Once Dan gives the go ahead, the first wall blocks are laid, which creates a buzz of renewed energy for volunteers who have begun to flag in the hot sun. In pairs, we set the dense blocks into the trench, check again with the levels, and nudge them into position, watching Dan’s practiced technique. 

Once the first row gets completed, the other rows turn out to be much easier. Thunk, thunk, thunk, up goes the wall. A Common Five-lined Skink (Plestiodon fasciatus) skitters out from hiding to inspect the work but gets briefly startled when scooped up by a volunteer. I wonder whether it will take up residence in the skink-sized spaces between the bricks of the new wall. 

Photo of a volunteer holding a skink
The Five-Lined Skink looks for a quick exit from human hands.

The final step for the day is to pour white rocks on the backside of the wall for stability. The re-energized crew makes quick work of slinging the weighty bags of rocks from the shed nearby, passing them up the small slope, and filling the trench. What started the day as an amorphous dirt mound has taken shape under the hands of this group. It’s satisfying to see the wall emerge.

Valerie expresses her excitement about the project, “Usually the children are up on the deck tripping over each other. When the Nature Center teaches its pollinator class now, they can be inside the garden, not outside and just pointing.” 

As pleased as the volunteers feel, the Saturday work was just the first step. The broader project requires making the upland soil more porous for percolation of water instead of surface flow. Valerie plans to insert an extra-large flowerpot with drainage holes drilled in the bottom into the soil below the roof-pour. But she faces the challenge that “when digging, we came across an electrical ground.” To dig further could risk damaging the electrical ground, which is marked off with tape.

Photo of a volunteer holding a large pot
Master Naturalist and pollinator garden leader Valerie LaTortue discusses how to increase soil percolation with Arlington County’s Extension Agent Kirsten Conrad (right).

The high schooler offers up the creative solution of putting a rain garden on the roof to catch the flow from the rain. Apparently, it would have to be accessed through the school, however, with permission from several entities. So, that’s an idea for another day. 

(All forms of life that are wild, including plants, animals, and microorganism – Natural Resources Service)

Photo of a Common Five-lined skink
Common Five-lined Skink (Plestiodon fasciatus) with tail that has been replaced after tail autotomy. Photo by Judy Gallagher via Flickr, CC-BY.

Common Five-lined Skinks (Plestiodon fasciatus) range throughout North America. They’re also called Blue-tailed Skinks because of a bright, metallic blue tail sported by juveniles and sometimes by females. Skinks (and some other lizards) can drop their tails off if grabbed by a predator – “tail autotomy” – likely an adaptation in which the tail keeps wiggling while the skink escapes. This species seeks out damp, wooded habitats where it hides under logs and bark on the ground. Females lay their eggs in decaying logs, typically in June. Five-lined Skinks feed on a variety of small invertebrates, including insects and spiders. Their cousins the Broad-headed Skinks (P. laticeps) also live in Virginia and elsewhere in the southeastern U.S., but they reach a larger adult size and spend more time in trees.  

Learn more on the Virginia Herpetological Society website about Common Five-lined Skinks.

It Takes a Village: Native Plant Sale at Long Branch Nature Center

Customer Evelyn picking up plants from Park Naturalist Jaron Winters.

Text and Photos by Devin Reese

Lots of customers came to Long Branch Nature Center on Saturday, May 7th, to pick up plants they had pre-ordered from the biannual Arlington County Native Plant Sale. When I first arrived to volunteer, I saw several people already working behind the table and just a single customer, and I figured the event was overstaffed. I was soon proven wrong as a steady stream of cars edged in and out of the tight parking spaces of the Nature Center lot. Passengers alit eager to carry off their selection of native plants, which kept us all pleasantly busy. The rainy weather definitely didn’t dampen any spirits.

Customer Evelyn, a dual language Arlington elementary school teacher, wanted to attract butterflies to her garden. She first become familiar with the types of plants that butterflies prefer when she taught science at Escuela Key Elementary School in Arlington. As Evelyn loaded several milkweed (Ascelpias) plants into her car, she talked about the joy of raising painted lady caterpillars (Vanessa cardui) through their metamorphosis to butterfly adults. She planned to create a native butterfly garden to enjoy and share with her students. 

Michele, another customer, had found her inspiration during the pandemic. While cooped up inside for the better part of two years, she watched her redbud seedling (Cercis canadensis) grow from what looked like twig to a proper plant. After acquiring it free from an Arlington native tree program, she had “babied it” through the pandemic and enjoyed the modest but apparent results. Michele was ready to nurse more native plants into growth, tickled that the redbud had survived and would likely “outlive” her! 

Photo of a cu
Customer Michele getting her tray of native plants.
Photo of a boy in a raincoat pulling a box with plants on a wagon
Alex’s son pulling their plants to the car in a wagon.

Some customers had budding young naturalists in tow. Dad Alex, once ARMN certified and now volunteering as District Manager of the DC Area for the Potomac Appalachian Trail Club, was led in by his son. The son chatted enthusiastically while waiting for the plants, reminiscing about his recent frog-themed birthday party hosted at Long Branch. He is a fan of red-eyed tree frogs and, clearly, of nature in general. The frog pond in his own back yard was reported to be teeming with tadpoles, likely wood frogs said his dad.   

As customers kept arriving, Park Naturalist Bobbi Farley keep things organized at the sign-in table. Duplicate lists of every plant order allowed volunteers and staff to divide and conquer: Ask for the customer’s last name; find it on one of sheets and assess roughly how many plants they ordered; have them wait while you go find their plants; deliver the order in a tray or box; review the plants to make sure the order is correct; check off the name. Bobbi’s voice rattled off plant names so they could be accounted for: “1 Jacob’s ladder – check; 6 Virginia bluebells – check; 2 wild geraniums – check.” As each order wrapped up, Bobbi called out, “Want a free bag?” Going on seven years that these sales have been held at Long Branch, Bobbi said “it’s great to get the word out about native plants to the community, including the ecological benefits to migrant insects and birds.” 

The system ran like clockwork, not only thanks to the multiple volunteers working alongside Nature Center staff, but also because it was well organized. Park Naturalist Jaron Winters (pictured above) did lots of the prep work. He reported that the hardest part was figuring out which species to sell and getting the complex order form together. He looked through catalogues of native plants to see what looked interesting, as well as considered what people bought in previous sales. Jaron predicted, for example, that Virginia bluebells would be a “big hit” and explained that most of the plants come from Environmental Concern’s wholesale plant nursery, and some from the Earth Sangha’s wild plant nursery. In the two years since he started at Long Branch, Jaron has gained a greater appreciation of sharing knowledge of plants with people.   

Photo of three people standing in a circle discussing plant size with hand gestures.
Master Naturalist Ginny McNair indicating the size of a mature wild ginger plant while Arlington County Conservation & Interpretation Manager Rachel Tolman looks on.
Photo of a volunteer placing a box of plants onto a wagon.
Naturalist Rita Peralta loading plants into a wagon.

Long Branch Nature Center and Outreach Manager Rita Peralta just started at the Park in February of this year. While she came with a background in wetlands, this was her first Long Branch plant sale and she was impressed with how Bobbi and Jaron successfully juggled the plants, customer orders, and volunteer signups.  But, of course, there were a few glitches, such as deer breaking into the supplier’s inventory and munching some of the plants. When something a customer had wanted wasn’t available, the Nature Center staff proposed a substitution. At pick up, each customer’s order was already compiled and labelled, including any recommended substitutions. That way, no money was returned, and in only one case did I notice a customer concerned about the substitution, because his wife had ordered the plants and was “very picky.” 


ARMN volunteers supported the Nature Center staff in keeping the day running smoothly. Ginny McNair (pictured above) completed the master naturalist training in 2010, followed by her husband Nick Nichols in 2013. Ginny has served various roles with ARMN, including leading training. Nick is a birder and capped off the day by spotting a red-shouldered hawk (Buteo lineatus) quietly presiding over the sale on a low branch. There were several scarlet tanagers flitting around too, which Ginny explained were seasonal migrants to the area. 

Red-Shouldered Hawk spotted by Master Naturalist Nick Nichols.

Find this biannual Arlington County Native Plant Sale, along with other native plant sales and additional information on natives on the ARMN website.

Wildlife (All forms of life that are wild, including plants, animals, and microorganism – Natural Resources Service).

Virginia Bluebells (Mertensia virginica) range throughout eastern North America but got their scientific name from the Colony of Virginia. Native Americans used bluebells to treat various ailments, including whooping cough and tuberculosis. Thomas Jefferson grew them at Monticello, conferred another common name of “Jefferson’s funnel flowers.” Indeed, they are funnel-shaped with a narrow tube culminating in a bell shape. Pollinators must reach for the nectar through the tube, making the flowers attractive to butterflies and hummingbirds, but only to long-tongued bees. Virginia bluebells are ephemeral, blooming for several weeks in the spring and by early summer going dormant. They die completely back to the ground but are perennials that renew the following spring. Learn more about Virginia Bluebells on the Virginia Native Plant Society website. See also: and

Virginia Bluebells (Mertensia virginica). Photo by Ryan Hodnett via Wikimedia, CC-BY-SA.

When Gardening for Wildlife, Pick Local Natives Over Cultivars Every Time

By Nancy Cleeland and Kasha Helget. Photos by Toni Genberg unless otherwise noted.

Looking to attract more insects, birds, and other wildlife to your garden by planting native species? Bravo! With only about 10 percent of our region dedicated to conservation lands, private native gardens are essential for maintaining healthy biodiversity.

But not all “native” plant species are created equal. It’s important to know the difference between true local native plants and cultivars—plants that go by variations of the same name but have been selected for size, color, bloom time, or even “pest resistance.”

According to Alonso Abugattas, Arlington-based author of the Capital Naturalist blog, research increasingly shows that the quest for prettier, smaller, longer-blooming or more vigorous varieties of popular natives is making many of them less attractive or useful to insects, birds and other wildlife. For example, bigger flower petals may come at the expense of nourishing nectar. The same chemical change that leads to redder autumn leaves might turn off an insect looking for a bite.

Not all changes introduced by cultivars appear to hurt their relationships with wildlife, but it’s still unclear what factors are at play.  Until more is known about these relationships, choosing a straight native will always be the safest choice, said Abugattas.

“Why take a chance on using a cultivar that may or may not support wildlife,” he asked, “rather than just choosing what generations of the birds and insects have already chosen through evolution?”

Instead of a cultivar, try a different local straight-species native plant

Matt Bright, who is Conservation Manager at Earth Sangha, the premier supplier of local native plants in the region, said he’s sympathetic to homeowners and landscape designers who use cultivars because they want a certain look or are bound by homeowner association rules. 

At least native cultivars are not harmful in the same way that non-native invasive species are, he said. “But I think sometimes cultivars become a crutch rather than grappling with difficult plant selection questions,” he added. “Maybe instead of dwarf hydrangea, there was the opportunity to use a straight-species Lowbush blueberry [Vaccinium pallidum] or a Mapleleaf viburnum [Viburnum acerifolium]? 

Or instead of planting a ‘gro-low’ fragrant sumac, you could try a Shrubby St. John’s Wort [Hypericum prolificum] or New Jersey tea [Ceanothus americanus]?”

Bright, who oversees seed collections and cultivation of local plants that are used in restoration projects throughout the region, said that when it comes to supporting wildlife, the more local the plant source, the more likely it will be to attract local wildlife.

That’s not to say that wildlife lovers should rip healthy cultivars out of the ground and replace them with locally sourced natives. After all, the cultivars could be providing some value.

“Like most things in nature it’s complicated and there are a lot of moving parts that we don’t understand fully,” Bright said. “That said, I think the evidence is clear that genetically diverse, locally-adapted, straight-species native plants are the gold standard for restoration and are an excellent choice for garden use.”

Looking for a place to purchase local straight species plants? This is one of the best times to find them at Spring native plant sales. 

Photo of two volunteers at a native plant sale
Joan Gottlieb from the Virginia Native Plant Society helps a customer at the 2021 Family Fall Festival at Green Spring Garden, Alexandria, VA.

And for more information on where to find locally sourced native plants, see Plant NOVA Natives and especially their page on cultivars vs. natives for landscape professionals.

Armed with the right information about particular natives and their suitability for your location, you’ll be able to choose plants that will support local native wildlife AND beautify your yard. It’s a win, win!

Photo of a monarch butterfly
Monarch butterflies (Danaus plexippus) are among the beautiful species attracted by native plants.

Transforming Upton Hill Regional Park

Text and photos by Devin Reese unless otherwise noted.

Many people know Upton Hill Regional Park for its popular recreational facilities—batting cages, mini golf, water park, and new climbing structure. The Park has its share of history, too, as a strategic vantage point used by both the Union and Confederate armies during the Civil War. But a walk with Park Steward Jill Barker, on trails that wind through about 15 acres, reveals a wild side of the park. 

Upton Hill harbors one of the few remaining forests in the Seven Corners area. With the hill standing at 402 feet, its naturally terraced layers purify the water emerging in seeps and springs at its base. Water percolates down through sieve-like layers of rocks and soils, getting naturally freer of particles as it goes. “The water originating from the Upton Hill springs has not been tested but may represent the highest quality natural water within Arlington County.” Natural Resource Specialist Greg Zell.

Photo of a stream in the park
Natural spring at the base of the park.

Every Thursday and monthly on Saturdays, Jill Barker leads groups of volunteers to remove invasive plants (RIP) from the park. 

Photo of a volunteer holding an invasive plant
Upton Hill Park Steward Jill Barker explaining which plants are invasive.

The Saturday I went, she gathered up the new people, equipped us with tools, and gave a walking orientation to the ongoing work to restore the park to native species. Jill explained how removal of the surfeit of invasives such as English ivy (Hedera helix), kudzu (Pueraria montana), and porcelain berry (Ampelopsis brevipedunculata), continue to open up space for native species to take hold. While saplings, such as oaks and elms, have been planted, she and NOVA Parks staff are also holding out hope that the seed bank in the soil will germinate to yield some long-dormant native plants. 

For example, Jill saw her first ephemeral flower in the park last year, a delicate, native bloodroot (Sanguinaria canadensis) known as a harbinger of spring. As we approached the park’s natural seeps, we found a gentle slope dotted with fan clubmoss, also called ground cedar (Diphasiastrum digitatum). Upton Hill is the only place that it grows in Arlington.

Photo of moss on the forest floor
Native Fan club moss.

Jill also pointed out the lone skunk cabbage plant (Symplocarpus foetidus)—which indicates good wetland habitat quality—peeking its first leaves up in the seep. We did not find the park’s two extremely rare flowers: Turtle Head (Chelone spp.), named for it two-lipped flowers that show up in late summer and fall; and poison sumac (Toxicodendron vernix), the rarest of the three Toxicodendron species in Virginia that is found at only two spots in Arlington.

What we did see in abundance is poison sumac’s familiar and equally-feared cousin, poison ivy (Toxicodendron radicans), snaking its way up trees.

Native to the east coast of North America, poison ivy belongs in the park, despite its toxicity to humans. And poison ivy is actually beneficial to many animals that eat the plant and use it as shelter or visit its flowers. Jill provided the volunteers with preventative skin wipes before we began immersing ourselves in invasives removal. And we discussed how it looked in vine versus leafing form, sometimes branching out onto trees in a weblike structure. 

Jill explained how, when she first started working in this park in 2019, the ground and trees were covered with invasive vines making a roof like a European Cathedral. 

Photo of trees and forest floor covered in vines
Upton Hill being overrun with invasive plants before the RIP program began.

“It was just horrible,” said Jill. Much of it was an invasive plant called five-leaf akebia (Akebia quinata). Along with Japanese bush honeysuckle (Lonicera maackii), it has been diminished through a combination of hand removal and targeted application of herbicides by NOVA Park’s invasive plant control contractors. 

Thanks to the context Jill provided, we went to work with our clippers and handsaws with a clear sense of purpose. A couple of us tackled a dense tangle of Japanese bush honeysuckle and a wickedly spiny invasive called multiflora rose (Rosa multiflora). It was prickly work, making one wish they had worn thicker pants and an impermeable jacket. But the tugging and clipping brought steady, satisfying results. Under the seemingly impenetrable mass of vines, we found native holly plants fighting for sunlight. “Free the holly!” became our mantra.

Photo of two volunteers in the woods helping each other cut down vines with a loper
Jill (left) and Volunteer Sue removing invasive honeysuckle vines.

Our several hours of work were a drop in the bucket in the hundreds of hours that staff and volunteers, including Boy Scouts of America and Mormon Missionary groups, have worked in Upton Hill Park. Invasives have been cut and pulled out. Cages have been erected around native saplings to protect their bark because deer love to scrape antlers on them. Jill is hoping that funding comes through for a 30 x 30-foot deer exclusion fence to see how a patch of soil freed from both invasive plants and deer browse responds.

Photo of a tree with damaged bark
Damage to a sapling from deer antler rubbing.

Jill Barker’s delight in the changes she has helped make to the park is palpable. And she looks forward to the long-term goal of not only restoring Upton Hill Park’s native vegetation, but also developing a wildlife corridor to the almost contiguous Powhatan Spring Park . (See related success story about work done at Powhatan.) This corridor will be a victory for those who have worked to remove the invasives, but more importantly, to the animals that depend on the native plants that can emerge!

Wildlife (All forms of life that are wild, including plants, animals, and microorganism – Natural Resources Service

Five-Leaf Akebia (Akebia quinata): 

Photo of a white flower with green leaves
Five-Leaf Akebia (Akebia quinata). Photo by Ursus sapien via Wikimedia, CC-BY-SA.

A woody, invasive plant, the five-leaf akebia can rapidly blanket an ecosystem. It’s one of about 40 species in the Lardizabalaceae family that’s native to Asia. A. quinata grows as a vine, spreading onto trees through vegetative propagation. It also spreads through sexual reproduction via pale purple to whitish clusters of flowers. A. quintana was purportedly introduced to the U.S. in 1845 by Robert Fortune, a Scottish botanist who had visited the island of Chusan in China. The 19th century witnessed its rapid spread through propagation as an ornamental for trellises and fences. Despite its deleterious impact on biodiversity, A. quinata is unfortunately still sold by U.S. plant nurseries. The flowers smell like chocolate, thus its nickname, chocolate vine. Learn more about Five-Leaved Akebia at: