Pear trees are usually propagated via grafting to a suitable pear rootstock. Pears don't root well in a rooting medium unless the donor tree is less than one year old. Cuttings from older trees very rarely will root via traditional methods. However, air layering works well for rooting pear trees. By selecting a young branch, you should have success with propagating from older trees.
Soak a handful of sphagnum moss in water for several hours before beginning to air layer your pear tree.
Select a young branch no larger than the width of a pencil.
Make two circular cuts about 1 1/2 to 2 inches apart around the entire circumference of a branch with a clean, sharp hobby knife or utility knife.
Make a cut along the direction of the branch between the two circular cuts.
Peel back the bark from between the two initial cuts to expose the wood.
Squeeze the excess water out of a handful of sphagnum moss and wrap the exposed wood with the moss.
Wrap a piece of polyethylene film several inches longer than the boss ball around the wound and wet moss.
Seal the edge of the film by rolling it together and apply electrical tape to the rolled edge to complete the seal.
Pull the ends of the film tight around the branch and tape them to the bark to seal the moisture in the sphagnum moss inside the plastic. This will keep the moisture and humidity in the moss and tree wound area.
Cut the branch off with a sharp pruning saw below the plastic film when you see roots on all sides of the ball of sphagnum moss under the plastic film.
Remove the plastic and moss carefully. Try not to disturb the new roots.
Plant the newly rooted pear tree in a pot with a good, well draining and balanced potting soil.
Water the pot thoroughly and wrap the entire pot, with the exception of the drainage hole in the bottom, in a polyethylene tent. Seal the tent's edges and top by rolling them together and affixing the edges with electrical tape.
Place the tented plant in indirect sunlight for four to eight days to allow the roots to further develop.
Begin acclimatizing the young tree to the lower humidity outside of the tent by poling two 1-inch holes in the plastic each day for five days.
Remove the plastic and begin moving the tree into mixed direct and indirect sunlight.