I planted a blue spruce (Pinaceae Picea pungens Engelm) the other day. My little off-sider, Jack, said "Pa, how long will it take to grow as tall as me?"
So I gave him a quiz. I put a nail in the trunk 6" from the ground. I then asked him how long it would take for the nail to be 48" from the ground if the blue cypress growns 1/2" a year.
He's still trying to work it out. Can you help him.