Callery pear (Pyrus calleryana)


Clusters of five-petaled, white flowers on a branch

Callery pear flowers. Photo credit: Ansel Oommen, Bugwood.org

 

Callery pear is a common ornamental and landscape tree in the central and southeastern U.S. that can spread into natural areas.

Description

Appearance

Callery pear is a compact, medium-sized flowering tree with white flowers. It can grow to 30-50 feet tall, with branches spreading 20-30 feet wide.

Leaves and stem

Leathery green leaves are arranged alternately along the stem (come off the stem one at time at each leaf node). They are 1.5-3 inches long and about as wide as long, with scalloped edges with a distinct ripple or wave. Callery pear leaves turn scarlet or purple in the fall. Bark is glossy brown when young while mature trees have grayish-brown, furrowed bark. Some individuals have stout sturdy spines.

Flowers

Flowers are white with five petals and about ¾ of an inch in size. They grow in clusters that bloom just before or as the leaves are expanding in spring. Trees can start flowering as young as three years old.

Seeds

Fruits are round and less than ½ inch in diameter. They are green to brown, with pale dots. Trees may produce large quantities of fruits.

Roots

Rootstocks can readily sprout when roots are nicked by lawnmowers.

Biology

Callery pear is a tree that is tolerant of a range of soil types and can tolerate some droughts and pollution. They are commonly found along roadside and forest edges, and have been a popular urban tree in the central and southeastern U.S. Although Callery pear is listed as being cold hardy to USDA Cold Hardiness Zone 5, some cultivars and hybrids have survived for a period of years in Minnesota in colder hardiness zones.

Origin and spread

Callery pear is native to slopes, plains, mixed valley forests and thickets in southeastern China, Taiwan, Korea, Japan, and Vietnam. Birds readily eat the fruit and spread the seeds. Individual Callery pear trees are not able to produce seeds on their own, but if there are different planted cultivars on the landscape, the two can cross-pollinate and produce fruit. The most well-known cultivar of Callery pear is the Bradford pear.

Refer to EDDMapS Distribution Maps for current distribution.

Don't be fooled by these look-alikes

  • Flowering dogwood, Cornus florida (native) – Flowering dogwood has opposite leaves, unlike the alternate leaves of Callery pear.
  • Nannyberry, Viburnum lentago (native) – Viburnums have opposite leaves, unlike the alternate leaves of Callery pear.
  • Crabapple, Malus species (Malus ioensis is native to Minnesota, other Malus species and cultivars vary in their nativity) – Crabapple leaves are distinctly toothed (as opposed to the more scalloped edges of Callery pear) and flowers can range in color from white to pink. The anthers in Callery pear flowers are purple while the anthers of serviceberries, crabapples, and plums are yellow.
 
Regulatory classification

Callery pear (Pyrus calleryana) is a Minnesota Department of Agriculture Specially Regulated Plant. Nurseries can sell this plant during a three-year production phase-out period from 2023-2025. Beginning in 2026, sale of this species will be prohibited, and the species will be designated as a Restricted Noxious Weed.

Threat to Minnesota
  • Callery pear is a fast-growing tree that can crowd out native plants.
  • Due to its fast growth, Callery pear often has weak structure and splits easily when exposed to ice and storms.
What you should do

One way that invasive plant seeds and fragments can spread is in soil. Sometimes plants are planted purposefully. You can prevent the spread of invasive plants.

PlayCleanGo: Stop Invasive Species in Your Tracks

  • REMOVE plants, animals and mud from boots, gear, pets and vehicles.
  • CLEAN your gear before entering and leaving the recreation site.
  • STAY on designated roads and trails.
  • PLANT non-invasive species.
Native substitutes
 
Control methods

Mechanical control can be done by digging or pulling small plants. Mowing or cutting can be used to prevent trees from reaching maturity and producing seeds, but the stumps will continue to resprout.

Herbicide control can be done using systemic herbicides, which are taken up by plants and move within the plant, killing leaves, stems, and roots. Cut plants will resprout if the stump is not treated with herbicide after cutting. Immediately after cutting (within 2 hours), apply an herbicide containing triclopyr (Garlon 3A/Vastlan, Garlon 4, or other brush killers with triclopyr) or glyphosate to the cut stump to prevent re-sprouting. Always follow label instructions for herbicides. Herbicides can be applied to cut stumps with a paintbrush, wick applicator such as a dauber or "buckthorn blaster," or a low volume sprayer. In cases where more than a few plants are treated, add an indicator dye (available where pesticides are sold), such as Mark-It Blue, to the herbicide to mark which cut stumps you have sprayed.

For basal stem treatment, a method that applies chemical through the bark, low volume spray applications can be made with Garlon 4, Pathfinder II and similar oil-based products. This application method uses triclopyr ester mixed with an oil diluent (i.e. Bark Oil Blue) applied directly to the bark of a Callery pear tree from the root collar up about 12-18 inches. An ultra-low volume spray wand should be used to minimize herbicide use and reduce the potential for non-target injury.

Reporting

Report new occurrences by submitting a report through EDDMapS, emailing Report a Pest, calling Report a Pest (1-888-545-6684), or contacting your local county agricultural inspector.

Resources

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