Pyrus calleryana Aristocrat Pear Size: 40 to 45' high by 20 to 25' wide. Hardiness: Zone 5 to 8(9). Habit: Moderately conical (pyramidal) in youth, and broadening with time, densely branched and foliaged making it one of the great widget trees in American commerce. Rate: Fast, 12 to 15' over an 8 to 10 year period. Culture: Sun.