Depending on the type of crepe myrtle tree a crepe myrtle tree reaches 10 to 20 feet in height.
However for the Dwarf crepe myrtle tree varieties they only reach a height of 4 feet tall which is when they are full grown.
Once a Dwarf Crepe Myrtle Tree reaches 4 feet of height they will usually never get any taller than that.
If you want to grow a larger Crepe Myrtle Tree you need to make sure you get the non Dwarf Variety.
Crepe Myrtle Trees are great trees and also the wood from Crepe Myrtle Trees make great canes which is what my Grandpa had.
I made my Grandpa a walking cane from a Crepe Myrtle Tree.
The Crepe Myrtle Tree also varies in leaf and bloom color and the Crapemyrtle reaches a height of 10 to 20 feet.