After two or three years, select a second tier of scaffold branches. Choose 3 to 4 shoots with wide crotch angles that are uniformly distributed around the trunk. No second tier branch should be directly above a first tier branch. Head back the central leader. Spreaders can be made by cutting a notch in each end of a piece of lathe or similar wood.
Manufactured spreaders are available from garden centers and mailorder companies.
Place the spreader between the central leader and the scaffold branch. Inspect the trees frequently and replace spreaders if they become dislodged. It may be necessary to replace the spreaders with longer ones as the limbs grow. The spreaders should remain in place for 2 to 3 years. The limbs should be stiff enough to remain in the desired position after this period.