University of Vermont
Department of Plant and Soil Science

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NEW CHOICE TREES AND SHRUBS

Dr. Leonard Perry, Horticulture Professor Emeritus
University of Vermont

Distinctive new, or underutilized, trees and shrubs suited for New England are given the Cary Award.  There have been eight winners between 2015 and 2018.

Named for a Massachusetts nurseryman, and administered by the Tower Hill Botanic Garden in Boylston, Massachusetts, the Cary Award is given to several landscape plants each year, as judged by a panel of professionals.  These are either new plant introductions, or others that aren't new but deserve wider use in landscapes. Over its 21 year history, 58 woody trees, shrubs and vines have been chosen.

Atlantic white cedar (Chamaecyparis thyoides) and Bottlebrush buckeye (Aesculus parviflora) are the Cary winners for 2018.  This white cedar is an elegant evergreen tree, native to the eastern seaboard states where it often is found in moist soils (but it will grow fine in average soils).  Foliage is generally blue-green, but may be plum colored in some cultivars (cultivated varieties).  Depending on cultivar, final heights may reach 20 feet as with Blue Rock, up to 50 feet high for the species (with 30 feet or more width).  This evergreen needs full sun, and is hardy to USDA zone 4 (average minus 20 to minus 30 degree minimum in winter).

Bottlebrush buckeye is a large shrub, native to the southeastern states but hardy into USDA zone 5 and the warmer parts of zone 4.  It reaches 12 feet high and spreads at least 12 feet or more wide.  The showy panicles of white flowers are 12 inches long, and in July cover the shrub in a cloud of white.  It is attractive to hummingbirds and various types of bees.  Although it prefers moist soils, it will tolerate wet to dry soils, once established.  Use it along woodland edges and in shrub borders. 

Gold Cone juniper (Juniperus communis ‘Gold Cone’) and fragrant or Korean abelia (Abelia mosanensis) were the Cary winners for 2017.  Gold Cone juniper makes a tight spire shape, reaching eight to 10 feet tall yet only 18 to 20 inches wide.  Its new growth in spring is bright yellow green, turning to soft green in summer.  It needs full sun, and is quite hardy (USDA zone 3 or an average annual minimum of minus 30 degrees or lower).  Discovered in New Zealand, it was introduced by a German nursery in 1980.

Korean abelia has rosy pink flowers in late spring to early summer.  The trumpet shape of the small flowers, held in clusters, is attractive to butterflies and hummingbirds.  Like other abelia, flowers have a sweet and spicy fragrance yet, unlike others in this genus, this species is hardy to USDA zone 4.  It will reach four to six feet high and wide and tolerates part shade and dry soils (once established).  This species is named for the south Korean town of Mosan. 

Two trees were Cary winners in 2016.  The dawn redwood (Metasequoia glyptostroboides) has, what I think, is one of most fun scientific names to say (me-ta-se-QUOY-ah glyp-toe-stroe-BOY-dees).  It has a fascinating history too, being found in fossil records dating back 50 to 100 million years ago.  It was thought extinct, until found in the 1940’s in China.  An expedition from the Arnold Arboretum in Boston collected seeds, distributing them to botanic gardens worldwide.  It is now found more commonly in the nursery trade than the wild, where it is still rather rare.

The dawn redwood is a rapid grower, reaching 100 feet tall with a pyramidal shape.  Its leaves are needles which are not evergreen, emerging bright green in spring, turning green in summer then rusty orange in fall before falling off.   It needs full sun, tolerates most soil types, and is hardy to USDA zone 4. 

The Japanese white pine (Pinus parviflora) ‘Glauca’ cultivar is more accurately a range of variations in the Glauca Group, similar to the eastern white pine.  It differs from the latter in being shorter (25 to 40 feet eventually, and the same width), slower growing and so less prone to winter and wind damage, with more picturesque shape, hardy to USDA zone 4, and this cultivar has very silvery blue needles.  It prefers well-drained soils, but tolerates most soil types when established.  Grow this as a specimen tree, in full sun.

European beech (Fagus sylvatica) are very choice trees for large landscapes, but the cultivar ‘Rohan Obelisk’ is a purple-leaved, very narrow upright form.  This 2015 Cary winner eventually reaches 50 feet tall but only 10 to 15 feet wide.  You may see it listed to USDA zone 4, but generally it is hardy only to the warmer zone 5 similar to most related species and cultivars.  It prefers a moist, well-drained soil in full sun, but will tolerate part shade.  In winter, its smooth gray bark—similar to other beeches—is quite attractive.

The other 2015 Cary winning plant was a less common shrub, but one deserving wider usage—Japanese clethra (Clethra barbinervis).  Unlike the lower, spreading native sweet peppeprbush (Clethra alnifolia), this one grows into a large shrub or small tree to 20 feet tall.  In late summer, it produces drooping clusters of flowers, lightly-scented, and which are attractive to pollinators.  The green leaves turn bright red, yellow and orange in fall.  In winter, the copper bark provides visual interest.  Hardy to USDA zone 5, this plant prefers a good soil in full sun to part shade.     

You can learn more about the Cary Award and many other choice landscape plants online at their website (caryaward.towerhillbg.org). Ask about these at your local full service nursery, as you won’t find these at chain outlets, and ordering woody plants online can be problematic.

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