My present house came with a Bradford pear tree in the front yard. The profusion of white flowers in spring and redish orange leaves in fall was pretty, and the tree had a nice shape. My wife and I had compliments on it. However, it seemed to grow faster every year. The flowers smelled progressively stronger as there were more and more of them, and they did not smell good. We gave up on keeping lawn grass under the tree, and created a flower bed around it. I trimmed the limbs to let more light under the tree and to give the house a better 
view from the street, and found the limbs easy to break. As time went on, increasing areas of the lawn around the tree wouldn’t grow despite everything we tried; more trimming, the flower bed was enlarged. When I had a hard time digging to plant coleus plants under the tree because of the mass of roots, I planted in containers. As I did this, I noticed a crack that had formed in the driveway which was about 10 yards away and wondered if the roots were to blame. When my wife found information on the internet about how Bradford pear trees are good for only 15 to 20 years, because the tree self destructs by splitting, I knew our 13 year old tree had to go before it got unsightly from its ultimate fate of splitting. After days of cutting and digging, we now have a nice flower bed in the place of our Bradford pear tree.
Bradford pears are fast growing trees, growing over 2 feet a year (older trees seem to grow even faster) up to 30 to 50 feet. They have dense and symmetrical upward growth with an egg-shaped to elliptical crown. Dense clusters of white flowers appear as leaves begin to develop in spring, and last 2 to 3 weeks. Flowers have 5 petals, and they have a disagreeable odor often compared to rotting fish. This is not so noticeable on small trees but is more noticeable on large ones due to the the numbers of flowers. Fruit are sterile and inedible. They are round with a large pit, less than an inch in diameter, and are mostly hidden by the thick leaves. Leaves are alternate, deciduous, broad, flat, and simple with a symmetrical, rounded base. Leaf edges have fine, double teeth. There is no petiole (leaf stem). Leaf color is dark green and glossy, and reddish orange in fall. Foliage is dense, and if you go under the tree in the evening you will 
most likely startle birds hiding there. There are many leaves to rake in the fall. The trunk is gray, and has structurally weak limbs. As the limbs get larger and heavier and experience the stress of bad weather, they tend to split. This typically happens in the 15 to 20 year range, but trees may last longer if shielded from rough weather. There are few trees more than 25 years old.
Interestingly, in 1916 fire blight was hurting the US commercial pear industry and a resistant variety of pear native to Asia, Pyrus calleryana or Callery pear, was brought in to help develop resistance to this pest. It gained use as a root stock for the common pear, Pyrus communis. Over time, ornamental possibilities of the Callery pear were recognized and different 
cultivars were developed. When the USDA introduced the cultivar Bradford pear commercially in 1963, it was structurally weak but pretty, and not intended to produce fruit. It became very popular for helping sell houses and to decorate business properties.
However, when this cultivar was grafted onto root stocks of other cultivars, these root stocks often produced shoots. These shoots can cross pollinate with the grafted Bradford pear and produce viable, marble sized, tart tasting Callery pear fruit of no commercial value comparable to crab apples, and they are spread by birds across the countryside. The result is dense thickets of Callery pear trees producing viable fruit and 4 inch thorns capable of 
puncturing tractor tires. The thickets spread quickly and are difficult to remove. The Callery pear was brought in to our country to help remedy a problem, but became an even bigger problem.
The Bradford pear was developed to be an excellent ornamental tree. It was visually pleasing, fast growing, had few insect or disease problems, and did not reproduce by itself. Despite the problems that have become apparent with this tree, it could still be a good ornamental if the tree is intended for short term use and if no other cultivars are around with which to cross pollinate, including grafted root stock of another cultivar. But I wonder, if the contractor who planted my Bradford pear had known all this, would he have planted this tree?