Renovating the Glenstone Museum Arrival Hall Landscape

Guest Blogger Calvin Perry

June 2nd, 2023

 

The outdoors have always been a place of comfort and respite throughout my life. Growing up, there was a Forsythia bush in front of my parents’ house that I would crawl into and hide among the flowers and leaves. There, I was as happy as could be. Some of my earliest memories are sitting inside that shrub. I also joined Scouts and gained my Eagle Scout rank in 2013, finding myself deeply connected to the natural environments I experienced throughout the program. After a brief time doing production work for local radio stations, I knew that a career in the outdoors was the calling for me.

 

I began working at Glenstone in 2019 as a general Grounds member and moved on the next year to an Area Horticulturist position at the museum. This put me into the primary role of overseeing approximately 27.5 acres of the campus, based around the Environmental Center and Arrival Hall buildings. The campus is broken up into 4 general areas and an Area Horticulturalist oversees each of these, guiding the landscape to its intended aesthetic and function within each area.  The landscape in my zone of management is a mix of open meadow, re-forested areas, riparian buffers, and stream zones.    

 

Located in Potomac, MD, Glenstone is a museum which focuses on seamlessly integrating art, architecture, and nature into a serene and contemplative environment. The name “Glenstone” derives from two local sources: Glen Road, where the property line begins, and a type of Carderock stone indigenous to the area, which is still extracted from several nearby quarries. Glenstone offers nearly 300 acres of landscape, which is fully integrated with the site’s architecture and art. The landscape includes paths, trails, streams, meadows, forests, and outdoor sculptures throughout the grounds. Glenstone has followed an organic approach to landscaping since 2010, so mechanical removal of unwanted plants plays a large part in how the campus is maintained. 

 

 

The first planting around the Arrival Hall occurred in 2018, and there was initial success in maintaining the bed as was designed. The 2018 planting design at the central Arrival Hall bed had a green and gold (Chrysogonum virginianum) groundcover that would slowly grow to form larger masses in the area. Downy skullcap (Scutullaria Incana), large-leaved aster (Eurybia macrophylla), heart-leaved aster (Aster cordifolius) and Pennsylvania sedge (Carex pensylvanica) were then plugged along the pathway edge and throughout the bed to then self-spread. These plantings did well for several years, but as the canopy began to mature and the growing conditions changed, the green and gold was outcompeted by mouse-ear chickweed (Cerastium fontanum) in the winter and Japanese stiltgrass (Microstegium vimineum) in the summer. The green and gold did not have enough height and aggressive growth to push out unwanted plants, leading to more work having to be done each year to maintain the desired look. A better solution was needed; therefore, a plan was set out to replace large portions of green and gold and incorporate a more diverse mix of shade loving plants. One section of downy skullcap was left along the perimeter as it was aggressive enough to hold its own throughout the growing season and provided nice overwinter interest with its dried seed heads.  This project was done in conjunction with my certification from the Chesapeake Bay Landscaping Professional (CBLP) program and served as the first-year project for my Level 1 certification. 

 

 

Landscape Plugs (LP50) were sourced from North Creek Nurseries, and all plants were selected for their strong deer resistance. A main groundcover of golden groundsel (Packera aurea) was chosen due to the great levels of success this plant had in other areas of the campus already.  An aggressive plant that spreads by seed and stolons, golden groundsel can suppress unwanted plants from germinating much more successfully than the green and gold. This groundcover was paired with musk sedge (Carex muskingumensis) and fox sedge (Carex vulpinoidea) to add a mix of textures for our groundcover plants. Both sedges fare well in the lower light conditions this bed is shifting toward. 

 

 

When looking at the surrounding area, it was noted that there was already a large mass of short-toothed mountain mint (Pycnanthemum muticum) across the pathway in an adjacent bed to the central one. To further its spread and link this central bed to the rest of the landscape, a large mass of short-toothed mountain mint was planted where we  assumed nature would eventually blow seeds from the adjacent bed. Being a mint, this species can be incredibly aggressive when in the optimal growing conditions, but this is what we were aiming for on this site. The tougher and more aggressive a native plant is, the more the plant will be able to withstand encroachment of unwanted species.

 

 

Foxglove beardtongue (Penstemon digitalis) was incorporated due to the success it had in beds adjacent to the central one and throughout the campus. Foxglove beardtongue was one of the species in our initial 2017 foundation meadow seeding and has proved to be a very active self-seeder, spreading very well in preferred conditions. This plant prefers full sun, but can grow well still in part shade; therefore, the plugs were positioned in locations that would provide the most sun in the bed.

 

 

Blue cardinal flower (Lobelia siphilitica) was mixed into the plant choices as well, a new choice for the area. We had prior success with red cardinal flower (Lobelia cardinalis) because the plant added a late season pop of color on tall stems, but it tends to prefer locations that receive more sunlight. With blue cardinal flower, deeper shade is preferred; therefore, we felt the same positive results could be achieved in this bed as were achieved with red cardinal flower in full sun areas. 

 

 

Because this is one of the first beds visitors see when approaching the museum from their vehicles, all work had to be completed within the 3 days we are closed to the public. A team of 6 worked on the first day to remove the green and gold in the bed and take it off site. On the second day, a team of 7, including myself, worked on planting the newly selected material. A grid pattern of 1’ intervals was marked on the ground after the original plant material had been removed to act as a guide when planting the mix of plugs. Behind the worker marking, another worker followed with an auger, making holes at least 5” deep for the plugs to be placed in. Excluding the mass planting of mountain mint, the plugs were then randomly placed into these predrilled holes in order to create a good mixture within the bed. 

 

 

Watering of these plugs occurred periodically after the replanting to ensure their good establishment. Mechanical removal of the undesirable plants that germinated in the bed was actively done throughout the year to ensure the plants had as little competition as possible during establishment. After this first year of establishment, watering was stopped and weeding continued. Leaf mulch was also added to the bed by removing fallen leaves and mowing them on the adjacent path and blowing them back into the bed.

 

 

By listening to and watching the 300+ acres of landscape around us at Glenstone, we have been able to identify native plants that show their resilience in the field. We then continue to encourage their spread by plugging more into the landscape in areas that favor their growth.  We hope that by giving visitors to the museum the opportunity to experience what a native Maryland landscape looks like at their own pace, this will encourage them to bring these land management practices back home with them. I hope the same impact is felt from this write up. I’ll see you in the field! 

 

 

 

Calvin Perry works as an Area Horticulturist at Glenstone Museum in Potomac, MD. He is a certified Level 1 Chesapeake Bay Landscape Professional and uses habitat restoration and renewal as the driving force behind his work. Having graduated from UMBC with a BA in American Studies, he is currently pursuing a Masters of Science in Environmental Management through the University of Maryland, Global Campus, while working at the museum.

 

All Level 1, Chesapeake Bay Landscape Professionals are asked to submit one hands on project during the first year they are certified. These projects are measured and documented by us to demonstrate to positive impacts of our professionals. This blog post is the third in a three part series featuring hands on projects. Interested in seeing more projects? Join us for a  “Today’s Menu” July 21st.