Chapter 126 Pyrus calleryana

126.1 Callery pear, Bradford pear

A Bradford Pear (Pyrus calleryana) bonsai on display at the National Bonsai & Penjing Museum at the United States National Arboretum. According to the tree’s display placard, it has been in training since 1977. It was designed by the museum’s first curator, Robert F. Drechsler. Link to original image.

126.2 Soil: General Deciduous / Rich Conifer Mix

Ratio: 3 parts bark, 1 part grit

Add-ins: dolomitic limestone (~5 lbs/yd), Tree-Tone (15 lbs/yd)

pH: ~6.5 (slightly below neutral)

Moisture: Average

126.3 Light

Routine: they do best in full sun.

Summer: unknown

126.4 Cultivation Notes

Close-up view of pear blossoms. Link to original image.

126.4.1 Potting & Root Pruning

Schedule: unknown. Assuming early spring.

Notes: I have successfully dug up trees up to 3 feet tall in spring while they were in bloom with no prior root pruning. Larger trees seemed to lack sufficient roots to survive, but I expect they would do much better if I had the opportunity to root prune them the preceding fall.

126.4.1.1 Top & Branch Management

Heavy pruning: while dormant in late winter.

Fine pruning: unknown.

Leaf pruning: unknown.

126.4.2 Feeding

Feed with a balanced fertilizer at half normal dose starting just after spring leaf-out.

126.4.3 Pests & Problems

Chemical Warnings

126.4.4 Winter Storage

A callery pear in winter. Without the leaves, it is much easier to see the narrow branch angles that make these trees prone to splitting. Link to original image.

Unknown.

126.5 Propagation Notes

Bradford pear in fall colors. Link to original image.

Bradford and callery pears are widely available in garden centers in spring. Escaped trees can be root pruned in fall then dug out in spring. Plant trees in open ground to develop their taper very quickly.

126.6 Artistic & Styling Notes

126.7 Additional Information

126.7.1 Natural History

A species of pear tree native to China and Vietnam. The most commonly known cultivar is ‘Bradford,’ which is widely planted throughout the United States and generally considered to be an invasive species.

126.7.2 In Cultivation

Callery pears have two very distinct personalities. On the positive side, they bloom profusely in spring, providing much-needed early pollen and nectar for bees that are emerging from winter hives. They grow rapidly to mature size, and provide reliable red to purple fall color.

Their biggest drawback is that they are very invasive. In the 1950s, callery pears were introduced as a promising new ornamental tree. By the 1980s, the structural weakness became obvious, followed by increasing numbers of escapees. Trees sprout readily from the seeds of small fruits that pass through birds. Colonies are common now along roadsides and in un-mowed field edges. This actually is an advantage for bonsai artists in that starter trees are widely available. Often landowners will let you dig them out for free.

The second drawback is that these pears are short-lived. Most do not survive more than 25-30 years.

The third drawback is important for landscape use, but less so for bonsai. Pears are notorious for having narrow branch angles. As the branches enlarge they trap bark from the top quarter of the branch collar. The bark weakens the fusion point, making branches prone to split in the wind or under a heavy snow or ice load. Branches on bonsai are not as likely to split under such loads.