UT Gardens' Plant of the Month:
Umbrella Pine

Submitted by Andrew Pulte

Visiting the Kiso Valley in Japan would be a dream pilgrimage for any conifer lover. Nestled within the southern region of the northern Japanese Alps, between Osaka and Tokyo, this valley is home to active volcanoes and some of the most spectacular trees on earth.

The Kiso Valley is the natural habitat of Hinoki false cypress (Chamaecyparis obtusa), sawara or Japanese false cypress (Chamaecyparis pisifera), and asuhi or false arborvitae (Thujopsis dolobrata). However, without a doubt, the biggest thrill would be to see a tree known as koya maki, known in the northern hemisphere by its common name umbrella pine (Sciadopitys verticillata). This tree is revered by all those who know and love conifers.

Many patient collectors are now planting umbrella pine in their own gardens. It takes patience because umbrella pine is a very slow-growing tree. With a growth rate at just over 6 inches a year, it will be 100 years before trees like those in the Kiso Valley will be on display in North America. Still, with a little soil preparation and thought when placing this tree, gardeners in USDA Zones 5 through 8A can begin to grow this fantastic conifer.

Those who lack well-drained soils need to amend them before planting. Umbrella pine does best in a full-sun to partial-shade situation where it has room to grow. This plant is both rare and hard to propagate, so it is more expensive then many other conifers and is often planted as a single specimen. Even with the extra cost and possible extra work with soil amendments, this tree is sure to become the centerpiece of any garden.

Some facts about Sciadopitys verticillata –

• Habit: Umbrella pine is an evergreen, coniferous, small- to medium-sized tree. It is dense and compact when young, opening up with age, eventually reaching 25' to 40' tall with a spread between 15' to 20' wide. Its shape can vary from broadly pyramidal to almost spire-like.
• Foliage: The umbrella pine has large linear leaves in terminal whorls of 20 to 30, and these leaves are 2" to 5" long and somewhat flattened. The large needles are dark green and glossy. They persist 3 years.
• Bark: The reddish-brown bark exfoliates in shreds or strips.
• Culture: Rich, moist, well-drained and acidic soils are best for growing umbrella pine.

The location should feature full sun to light shade. An umbrella pine is among the many unique and fascinating plants on exhibit at the UT Gardens in Knoxville. For more information on conifers visit the Web site of the American Conifer Society at http://www.conifersociety.org.

Andrew Pulte is a graduate student in the University of Tennessee Department of Plant Sciences. He works under the guidance of Dr. Susan Hamilton, director of the UT Gardens. The UT Gardens are a project of the Tennessee Agricultural Experiment Station. The original gardens are located in Knoxville on Neyland Drive. Additional gardens are located in Jackson on Airways Blvd. Admission is free, and the Gardens are open to the public seven days a week during daylight hours. More information is available online at http://utgardens.tennessee.edu

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Contact:

Patricia C. McDaniels, (865) 974-7141