Now that they have been so popular for so long, the deficiencies of flowering pear, Pyrus calleryana, (which is also known as Callery pear), are becoming increasingly evident. The dense branch structure and compact form that are so appealing while trees are young compromise structural integrity as trees mature. Symmetrical trees can be severely disfigured if limbs get broken by wind.
In the past, flowering pear had been quite resistant to disease and insect infestation. However, now that there are so many of them within minimal proximity of each other, it is nearly impossible to avoid infection with fire blight. To make matters worse, they share this very contagious bacterial disease with fruiting pear, evergreen pear (fruitless) and apple (fruiting and flowering crabapple).
Otherwise, healthy and well structured trees provide some of the best autumn color for mild climates. Foliage that was rich green through summer becomes bright yellow and orange on a weak season, with more bright red and burgundy with a good chill. The white spring bloom is likewise more colorfully profuse after a colder winter, although some find the fragrance to be objectionable.