June 11, 2013
Pyrus calleryana cvs.
Callery Pear

DescriptionCallery Pear cultivars are widely popular for the lovely floral show each spring, compact size and pest resistance. Lovely bloom, glossy leaves, interesting fall colour, fast growth and urban tolerance maintain the appeal of this small tree.
UsageParking lot island, buffer strip, highway, shade tree, street tree.
OriginKorea, China, Japan, Vietnam
Hardiness zone4,5
Form/textureBroadly pryamidal, open, wide branch angles.
Growth rateFast.
LeafDark lustrous green and wavy edge makes them showy, turning yellow to deep red in fall.
FlowerWhite, very showy in May.
FruitSmall brown or tan, attracts birds, persistent.
Exposure/cultureFull sun.
Tolerates very wet to very dry soils.
Tolerates wide range of pH.
Moderately tolerant salt spray (Beckerman et al, Morton).
Pollution resistant.
Easily transplanted.
CommentsWith great urban tolerance and aesthetic appeal the Callery pear is a frequent choice for landscapes. Newer cultivars have improved on the widely planted but brittle and weak-wooded 'Bradford' (Gerhold).

'Aristocrat' is one of a few cultivars with strong branch arrangement and improved winter hardiness.

Overuse of this tree has increased susceptibility to disease and to placement on the invasive lists of the U.S. (http://www.invasiveplantatlas.org/trees.html). Callery Pears are naturally self-sterile, but will readily cross-pollinate other cultivars. Control of existing trees is difficult due to resprouting (Culley et al). Restricting Callery pears to extreme urban spots where few others will grow may curtail the invasive threat. Choosing other trees where possible will improve the diversity of urban plantings.

CultivarFormDiseaseFall colourOther
Chanticleer (Cleveland Select)Upright, narrow pyramidTolerant to fireblightGold-red to plumEnters dormancy earlier than other cv's
RedspirePyramid to oval, dense, slow growingTolerant to fireblightYellow in fallMany flowers
Leaves thick shiny green
Autumn BlazeRounded, open, wide branch anglesSusceptible to fireblightEarly, reliable redMore right-angle branching than other cv's
AristocratBroadly pyramidal, openSlightly susceptible to fireblightYellow to deep redLater bloomer, fewer but still showy flowers.
Leaves have wavy margin

(Bassuk et al)

Bassuk, N., D. F. Curtis, B.Z. Marrance, and B. Neal. 2009. Recommended Urban Trees: Site Assessment and Tree Selection for Stress Tolerance. Urban Horticulture Institute. Ithaca, NY.
Beckerman, J. and B.R. Lerner. 2009. Salt Damage in Landscape Plants. Purdue Extension Publication ID-412-W. Purdue University. West LaFayette, IN.
Culley, T. M. and N. A. Hardiman. 2007. The Beginning of a New Invasive Plant: A History of the Ornamental Callery Pear in the United States. BioScience 57(11): 956-964.
Gerhold, H. D. 2007. Callery Pear Cultivars Tested as Street Trees: Final Report on a 12-Year Study. Arboriculture and Urban Forestry 33(2): 153-156.
Kuser, J. E., Robinson, G., and Polanin, N. 2001. Four-year evaluation of five cultivars of Pyrus calleryana. Journal of Arboriculture 27(2): 88-91.
Morton Arboretum Salt Tolerant Trees. Michigan State University Extension Service Publication, HM-95.