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Illustration of Eastern Hemlock by Charles Faxon

Hemlock Hill plants

Hemlock Hill
Hemlock Hill


Fun Facts

  • 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.

  • 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.

  • Planted along the lower northern contours, Kalmia latifolia (mountain laurel) flower profusely between late May and early June.

  • Frequently associated with Hemlock Hill, Rhododendron Dell features many species and cultivars of Rhododenron that typically flower between early May and early June.


Hemlock Hill, the largest Arboretum woodland, occupies 22 acres. It has had a complex history of disturbance, including the 1938 hurricane and arrival of the hemlock woolly adelgid. This woodland is home to a number of unique birds, amphibians, ferns, and herbaceous perennials that prefer the shady understory of dense forestland. Prominent non-native plants include glossy buckthorn (Frangula alnus), castor aralia (Kalopanax septemlobus), mountain ash (Sorbus spp.), and hawthorn (Crataegus spp.). Hemlock Hill collections inform research and feature prominently in ecosystem studies for Boston Public School fifth grade students.


Read more about Hemlock Hill in Arnoldia:

  • 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]

Featured Plants

Illustration of Ginkgo by Charles Faxon
1113-89*C Map it ↗


Scientific Name
Ginkgo biloba

In the early 20th century, American and European botanists believed that the ginkgo, while common in cultivation, was extinct in the wild. This ginkgo was collected from one of the few presumed wild populations of this species in China.

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Ginkgo biloba
Illustration of Heptacodium
1549-80*B Map it ↗

Seven Son Flower

Scientific Name
Heptacodium miconioides

A botanist at the Arnold Arboretum officially named and described the seven son flower in 1916. But the species would not be grown in the United States until 1980. This plant was among the first.

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Heptacodium at AA

Plants in this Collection

Plant ID Accession Date Received As Origin Source

Featured Walk

This quarter-mile tour through the Explorers Garden features stories from the Arboretum’s century and a half of collecting plants around the world. If you’re at the Arboretum, click here to take a version of this tour with Expeditions, our mobile web app.

Dove tree (Davidia involucrata)

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