Hemlock Hill

Hemlock Hill


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Hemlock Hill (22 acres/10 hectares) collections inform research and feature prominently in ecosystem studies for Boston Public School fifth grade students. Over its history, Hemlock Hill has been impacted by human, insect, and environmental events. Benchmarks include:

  • 1600s-early 1800s – Extensive removal and/or culling of trees leave the hill in a constant regenerative state.
  • ~1810 – Benjamin Bussey aquires much of what is named “Hemlock Woods.”
  • 1840s – Margaret Fuller and other members of the Trancendentalist circle frequently visit the landscape.
  • 1842 – Benjamin Bussey wills his estate to Harvard College.
  • 1872 – Harvard College accepts the James Arnold bequest, executes the indenture of the Arnold Arboretum, and agrees to locate the Arboretum on part of its Bussey estate, “Woodland Hill” in West Roxbury.
  • 1883 – Arboretum land is taken into the Boston Park System and leased ($1.00/yr.) back to Harvard College for one thousand years.
  • 1907 – The first accession of Chinese hemlock (Tsuga chinensis 6851, E.H. Wilson #952) is planted and survives until 1921.
  • 1932 – Fire, fanned by a stiff wind, runs up the southwestern face of the hill, scarring the landscape and destroying a grove of Japanese yew (Taxus cuspidata).
  • 1930s – “Indian camp relics” (e.g. projectile points) are found in the area.
  • 1938 – The Great New England Hurricane topples a significant number of eastern hemlocks, leaving a pit and mound topography along its northern slope; a combined total of 400 trees (oak, hemlock, etc.) are lost.
  • 1940 – Approximately 200 additional hemlocks, having been grown in Arboretum nurseries, are planted on Hemlock Hill in the fall.
  • 1946 – An Asa Gray collection (ca. 1843, Tennessee) of Buckleya distichophylla (piratebush) is transplanted from the Harvard Botanic Garden to Hemlock Hill and becomes the the oldest cultivated plant in the Arboretum’s collections.
  • 1997 – Hemlock Woolly Adelgid (Adelges tsugae; HWA), an exotic pest native to Asia, is found on numerous native eastern hemlocks on Hemlock Hill.
  • 1998 – Approximately 99% (1,904 plants) of the eastern hemlock population are accessioned for long-term monitoring.
  • 2004 – Collaboration begins with Harvard Forest to examine the long-term ecological impacts of eastern hemlock loss. Three of the six research plots (15x15m) established on Hemlock Hill are logged (136 hemlocks removed).
  • 2008 – Betula lenta (black birch) are found to be heavily represented in the seed bank and thickly populate the Arboretum’s logged plots (circa 2004). Since the discovery of HWA in 1997, 30% of the eastern hemlock population have died.
  • 2013 – Elongate Hemlock Scale (Fiorinia externa; EHS), an invasive scale from Japan and China, are observed for the first time on both Tsuga canadensis and T. chinensis.

Historic views of Hemlock Hill are made available by the Arnold Arboretum Horticultural Library.

Read more about the impact of Hemlock Woolly Adelgid by clicking on the Arnoldia and More » tabs above.

  • Tsuga chinensis (Chinese hemlock), a close relative of our native species (Tsuga canadensis), are fully resistant to Hemlock Woolly Adelgid (HWA). Find these young, approximately 9-foot-tall specimens growing along the wide path that leads to the summit of the hill. [pdf]
  • Buckleya distichophylla (piratebush) is oldest cultivated plant in the Arboretum and is one of many accessions with rich documented stories. Find it thriving where the wide path from Hemlock Hill Road flattens out after a moderately pitched rise; near a semi-circle of arranged white pine (Pinus strobus) logs. [pdf]
  • Planted along the lower northern contours, Kalmia latifolia (mountain laurel) flower profusely between late May and early June. [pdf]
  • Frequently associated with Hemlock Hill, Rhododendron Dell features many species and cultivars of Rhododenron that typically flower between early May and early June.

Search our inventory for additional accessions information or access our collections using your mobile device via Arboretum Explorer!

Hemlock Collection

Hemlock Hill is bounded on the south by Bussey Street and on the east by South Street. To explore the northern portion of Hemlock Hill, enter the Arboretum through the South Street Gate and approach Hemlock Hill on the left side of Hemlock Hill Road. The western side of Hemlock Hill is located less than five minutes from the Bussey Street Gate or the Walter Street Gate. If driving, park along Bussey Street or in front of the South Street Gate.

Hemlock Hill has the third highest elevation at the Arboretum. It is not wheelchair accessible. Use caution; the terrain is rugged and may be muddy. From Rhododendron Path, a small wooden bridge crosses Bussey Brook and leads to a dirt path that circles the base of Hemlock Hill parallel to South Street. A wide gravel path leads from Hemlock Hill Road about halfway to the top, and numerous unmaintained dirt paths traverse the hillside.

An information kiosk at the Bussey Street Gate provides seasonal updates. Map tables at the Bussey Street Gate, the South Street Gate, and the intersection of Valley Road and Hemlock Hill Road provide Arboretum wayfinding information.

How long should I explore?
Allow approximately fifteen minutes to hike from the wooden bridge around the base of Hemlock Hill. Walking the wide gravel path to the top of the hill may take approximately twenty minutes. Plan to spend up to one hour if exploring the hill’s many small paths.

Plan your visit to the Arboretum.

  • Del Tredici, Peter. 2010. Chinese Hemlock Tsuga chinensis. Arnoldia 68(2): 65-68. [pdf]
  • Havil, H.P., M.E. Montgomery. 2008. The Role of Arboreta in Studying the Evolution of Host Resistance to the Hemlock Woolly Adelgid. Arnoldia 65(3): 2-9. [pdf]
  • Schulhof , Richard. 2008. Ecosystems in Flux: The lessons of Hemlock Hill. Arnoldia 66(1): 22-28. [pdf]
  • Del Tredici, P. 2004. Finding a Replacement for the Eastern Hemlock: Research at the Arnold Arboretum. Arnoldia 63(2): 33-39. [pdf]
  • Fordham, Alfred J. 1963. Tsuga Canadensis and its Multitude of Variants. Arnoldia 23: 100-102. [pdf]

Search for related articles in Arnoldia, the magazine of the Arnold Arboretum.

More »
  • Learn more about research on Hemlock Hill and the Arboretum’s response to Hemlock Woolly Adelgid (HWA; Adelges tsugae).
  • Find answers to frequently asked questions about HWA courtesy of the UMASS Extension Service.
  • Read Harvard Forest publications related to invasive plants, pathogens, and pests (including HWA).
  • The HWA Forest Heath Protection Program, managed by the USDA, aims to protect the long-term health and sustainability of northeastern forests.
  • Tsuga (hemlock) is one of six conservation genera held by the Arnold Arboretum for the Plant Collections Network.
  • The Gymnosperm Database offers descriptions of conifers including the genus Tsuga.