Question
Can I digg up my blooming pear tree? It's about 15 feet tall.

Answer
Deciduous plants like Bradford pear may be moved in the spring as soon as the frost is out of the ground, up until the time when new foliage is partly unfurled. In the fall, they may be planted once the leaves start to turn color up until the ground freezes.
It can BUT it will be a large heavy job.
Although all trees and shrubs can be moved in either spring or fall, there are some which establish themselves better when moved in the spring, such as the softwoods (willows, poplars, birches).

When you want to dig up a tree or shrub for transplanting, retain as much of the root system as possible. Deciduous trees can be successfully moved only if a ball of soil is left around the roots. The exposed roots should be protected with moist burlap or newspaper or with polyethylene sheeting. Every effort should be made to reduce root exposure to wind and sun, keeping the ball as moist as possible. It's best to prepare the hole before digging up the tree you wish to move.
Size of the root ball and size of the hole:

For deciduous trees and shrubs the soil ball should be:

Width = 9-12 in. in diameter/every 1 in. of tree diameter
Depth = 6 in./every 1 in. of tree diameter

For example: A tree trunk 2 inches wide would need a soil ball of 18-24 inches wide and 12 inches deep.

To ensure that the soil ball is not disturbed when moving, it should be held together with a piece of burlap or sacking. "Lace" the burlap with heavy twine if the tree is to be moved a considerable distance

The new hole should be twice the size of the rootball and as deep, fill with good top soil , mulch with not more than 3 inches of organic mulch and water. Remove the burlap or wrapping before planting. Do not fertilize for a year.