University of Vermont Extension 
Department of Plant and Soil Science

Anytime News Article


CHOICE LANDSCAPE PLANTS FOR THE NORTH
 
Dr. Leonard Perry, Extension Professor
University of Vermont
 
           
When choosing trees and shrubs for your landscape, consider ones that have received the Cary Award.  This is given each year to a small selection of plants deemed worthy by professionals of wider use.  Some are relatively new, others are just great plants. Unless noted, these prefer full sun and average, well-drained soils.
           
Trees to consider are the Korean Fir (Abies koreana), 'Soft Touch' White Pine (Pinus strobus), and the Paperbark Maple (Acer griseum).  Korean fir is of course evergreen, and forms a loosely pyramidal shape reaching about 25 feet high and about 10 feet wide.  The thick needles are green on top, with silvery undersides, making them quite attractive.  Also showy are the small, dark-violet cones that appear in spring.  It prefers full sun but will tolerate light shade.  Hardy in USDA zones 5 to 7, often to zone 4, its main use is as a specimen or accent tree. 
           
'Soft Touch' is a dwarf cultivar (cultivated variety) of white pine, selected at the University of Connecticut from a witch's broom.  This is the condensed growth one sometimes finds on the tips of evergreens.  Only reaching three feet high and perhaps five feet across, it grows slowly.  The soft blue needles are held on dense stems, and have a slight twist.  It should be hardy in USDA zones 3 to 7.
           
Paperbark maple is appropriately named for its papery, peeling reddish-brown bark-- perhaps its main attraction and the reason it is usually used as a specimen in landscapes.  This small tree reaches about 25 feet high and 15 or more feet wide.  The bluish-green leaves (divided in threes) turn a reddish color in fall.  It is hardy in USDA zones 5 to 7, and will tolerate a wide range of soils and soil acidity (pH). 
           
Large shrubs to consider are the 'Miss Kim' lilac (Syringa patula), 'Elizabeth' Yellow Magnolia, and Little Leaf Laurels (Kalmia latifolia var. myrtifolia).  'Miss Kim' is a Korean lilac, blooming a week or two later than the common lilac.  It has many small, violet-purple flowers in clusters, giving off a sweet scent in both full sun and part shade.  It slowly reaches five to eight feet tall and wide in USDA zones 3 to 8.  The small, dark green leaves resist powdery mildew disease.
           
'Elizabeth' is an outstanding shrub magnolia with fragrant, primrose yellow flowers, a trait unusual for this genus.  A cross between the Cucumber (acuminata) and Yulan (denudata) magnolias, introduced in 1977 by the Brooklyn Botanic Garden, it is hardy in USDA zones 5 to 8.  Blooms appear in late April and May on vigorous plants that may reach 35 feet high and half that wide. Unlike many shrub magnolias, it blooms at a young age.
           
Little leaf laurels are actually a group of small-leaved and compact versions of our native Mountain Laurel that were selected in Connecticut.  These slow-growing, evergreen plants reach about 3 to 4 feet high and wide, and are hardy in USDA zones 5 to 7, possibly colder. They will tolerate part shade, prefer acidic soils, and if in full sun should be protected from winds. Flowers are variations of pinks and reds, attractive against the evergreen small leaves. Cultivars to look for are 'Elf', 'Minuet', Tiddlywinks', 'Tinkerbell', and 'Little Linda'. 
           
Small shrubs to consider, often planted in mass as groundcovers, are the Lowbush Blueberry (Vaccinium angustifolium) and Three-toothed Cinquefoil (Sibbaldiopsis tridentata).  This low blueberry, compared to the more common highbush blueberry grown for its large fruit, reaches about two feet high and wide.  Native to the northeastern states, it is quite hardy (USDA zones 2 to 5), and prefers acidic soils.  It is attractive in many seasons, beginning with the waxy white flowers in spring that bees love, to the small dark fruits later in summer that birds love (sweet and juicy if you can get to them before the birds), to the red fall leaves that people love. 
           
The three-toothed cinquefoil is a lesser known plant, similar to and formerly classified as a potentilla.  Native to eastern Canada and the northeastern states, it is found in higher elevations through much of North America, so is quite hardy (USDA zones 2 to 8). As this native is listed as endangered in several states, make sure the plants you buy are nursery-grown.  It only gets about four to six inches high with a slow spread, so is good in rock gardens.  The dark evergreen leaves, divided into three leaflets, serve as a backdrop for the white five-petal flowers (similar to strawberry) in early summer.  Leaves often turn a nice red to maroon in fall. You may find the cultivar 'Nuuk', selected in Greenland and named for its capital city, with wine red leaves. 
           
More great woody landscape plants can be found on the Cary Award website (www.caryaward.org).
            

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