Our Publications 

Our preservation efforts on biodiversity, plant conservation, and ecological research contribute to sustaining and securing the future of plants.  

• Zale, P., Turner-Skoff, J., & Santos, K. (2025). The beauty of conservation – developing a science-based conservation horticulture programme at Longwood Gardens, Pennsylvania, USA. Sibbaldia: The International Journal of Botanic Garden Horticulture, 24(24).
  • While historically serving ornamental, medicinal and agricultural purposes, botanic gardens and arboreta have opened their doors to the public and have extended their missions to encompass the study, preservation, and support of plant diversity. This paper explores how Longwood Gardens has embarked on this journey, leveraging its scientific expertise to establish a conservation focus.
• Schmit, J. P., Johnson, L. R., Baker, M., Darling, L., Fahey, R., Locke, D. H., ... & Johnson, M. L. (2025). The influence of urban and agricultural landscape contexts on forest diversity and structure across ecoregions. Ecosphere, 16(2), e70188.
  • Urban forest patches support biodiversity and human well-being, but urbanization affects their health. This study analyzed 17 studies across four major U.S. cities to understand these impacts. Despite regional differences, urban forests shared common challenges, highlighting the need for focused conservation efforts.
• Darling, L. E., Rollinson, C. R., Fahey, R. T., Morzillo, A. T., Johnson, L. R., Baker, M., ... & Hardiman, B. S. (2025). Ecological and developmental history impacts the equitable distribution of services. Frontiers in Ecology and the Environment, e2841.
  • This is work with an environmental equity focus, looking at how history of urban land development and racial segregation affect current access to ecosystem services.
• Cano, Á., Powell, J., Aiello, A. S., Andersen, H. L., Arbour, T., Balzer, A., … Brockington, S. F. (2025). Insights from a century of data reveal global trends in ex situ living plant collections. Nature Ecology & Evolution, 1-11.   
  • A global study of botanic gardens reveals challenges in safeguarding the most threatened plants from extinction. Researchers examined records from 1921 to 2021 across fifty botanic gardens, which collectively cultivate half a million plants. The study suggests that living collections have reached their capacity, while restrictions on wild plant collecting are limiting efforts to preserve plant diversity. Ultimately, plant conservation has progressed substantially in the past decades, and this paper identifies the opportunities for continued efforts moving forward. Botanic gardens are incredibly important drivers of plant conservation.
• Johnson, L. R. (2023). Global biodiversity requires integrating social and ecological goals for urban biodiversity: Insights from ecological restoration. In Routledge Handbook of Urban Biodiversity (1st ed., pp. 346–360). New York, NY: Routledge. ISBN: 9781003016120  
  • Global biodiversity requires urban biodiversity because people living in cities will decide how much of the diversity of life on Earth today will travel with us into the future.
• Linsky, J., Bellemare, J., Berryhill, J., Conrad, K., Lobdell, M., Moon, B., de la Mota Daniel, F. J., Rahaim, K., Rounsaville, T., Sanders, A., West, T., Zale, P. J., Meyer, A., Beckman Bruns, E., & Coffey, E. E. D. (2022). Conservation Gap Analysis of Native Magnolias of the U.S. and Canada. Atlanta, GA: Atlanta Botanical Garden.
  • The report provides a comprehensive review of the ecology, distribution, vulnerability, and ex situ conservation status of eight Magnolia species native to the U.S. and Canada. It also presents findings from a conservation action questionnaire shared with a diverse group of conservation practitioners. This analysis is designed to inform organizations engaged in Magnolia conservation and inspire further collaborative efforts to protect these native species.
• ZALE, P.J., CLAYTON, A., NIX, J. & TAYLOR, M. (2022). Asymbiotic in vitro seed germination, in vitro seedling development, and ex vitro acclimatization of Spiranthes. Applications in Plant Sciences, 10: e11494
  • This paper provides reproducible seed propagation and production protocols for native orchid genus Spiranthes to facilitate ex situ conservation practices
• ZALE, P.J., MCCORMICK, M.K. & WHIGHAM, D.F. (2022). Choosing a favorable substrate to cultivate native orchids symbiotically: Examples using Goodyera tesselata and Platanthera blephariglottis. HortScience, 57: 634-642. 
  • U.S. native temperate terrestrial orchids are challenging to grow due to complex ecological needs, including a frequent reliance on mycorrhizal fungi. This study focused on Goodyera tesselata and Platanthera blephariglottis found that adding appropriate fungi improved growth and survival in most tested substrates, but success also depended on environmental and horticultural conditions.

We're pioneering innovative research for horticulture, propagation, and plant development.

• Aiello, A.S. (2024). Holly Society of America Journal. 42(2).
  • This article describes the past, present, and future of hollies at Longwood Gardens, highlighting a few of Aiello's favorite plants while also describing holly evaluations that are happening behind-the-scenes at the research nursery. 
• Aiello, A. S. (2024). Magnolia denudata: yulan, the grandfather of magnolia. International Dendrology Society, 2024 Yearbook, 18-36.   
  • Magnolia denudata, or Yulan, is a flowering tree native to China, valued for its pure, white blooms that appear in early spring. With deep cultural significance, it symbolizes candor and has been cultivated for centuries. Yulan also contributes to hybrid magnolias, influencing numerous modern varieties.
• Aiello, A. S. (2024) Around the World to Find the Whorled “Pine.” Arnoldia. 81(3), 16-17.
  • A recounting of a plant exploration journey in Japan’s Kii Peninsula to study Sciadopitys verticillata, the Japanese umbrella pine, detailing the challenges of field collection, the species’ horticultural significance, and efforts to document and conserve it. The author highlights the plant's rarity, historical introduction to the U.S., and its role in living collections, including at Longwood Gardens.
• Zale, P. J., & Aiello, A. S. (2023, Spring). Honeysuckles and hospitality. Arnoldia, 80(1), 13-16.   
  • Details a plant collecting trip focused on several North American azalea species Rhododendron alabamense and R. austrinum in southern Alabama and southwestern Georgia.
• Aiello, A. S., & Zale, P. J. (2022). Quest for Southern Red Oak—North of the Mason-Dixon Line. Arnoldia, 79(2), 11-13.
  • Based on biological and climatic threats to tree species traditionally grown at Longwood Gardens, this article focuses on our efforts to conduct plant exploration trips looking for native species that combine ornamental traits with disease resistance and greater heat tolerance. This project highlights efforts looking for the southern red oak (Quercus falcata) at the most northern part of its range.

We advance environmental responsibility through our work in soil health, substrate science, and material circularity. 

• Turner-Skoff, J. B., Johnson, L. R., Stefferud, E., Stratman, P., & Santos, K. (2024). Reimagining relationships with resources as a public garden: Case studies of Longwood Gardens’ sustainability and stewardship practices. Journal of Zoological and Botanical Gardens, 5(3), 481-491. 
  • Longwood Gardens is working toward a future where the beauty of nature can be enjoyed by all through its sustainability and stewardship efforts. Using case studies highlighting water quality and conservation, carbon footprint reduction, material circularity, and land stewardship, this paper examines the multifaceted approach that Longwood takes to address its environmental impact.

We illuminate the significance of plants through storytelling, feats of horticulture, and guest engagement. 

• Griffis, G. (2024). Longwood’s Orchid Chandelier: A Grand Feat with Grand Results. American Orchid Society Magazine.240-241.
  • Weighing in at more than 800 pounds (360 kg) and spanning a staggering 8 feet (2.4 m) wide, our team created an orchid chandelier as part of the 2023 A Longwood Christmas display.
• Aiello, A.S. 2023. West Mount Airy Canopy. Arnoldia 80(4): 60-63. 
  • This is a description of the remnant native tree canopy in a "suburban" type neighborhood within the City of Philadelphia. Tony discusses the natural history and the dominant species of the area. 
• Aiello, A. S. (2021). Thomas Meehan. Arnoldia, 78(5/6), 50-61. 
  • Thomas Meehan was one of the best-known American horticulturists in the late 19th century. As both a nursey owner, and as a horticultural writer and editor, he promoted a wide range of plants. This article provides insights into his history and impact.