I live in Texas zone 7b. We have crepe myrtles all over the city. I
noticed that the ones that are maintained in public areas and
businesses don't have any suckers at the bottom of the tree and they
look so neat. In my house it's another story. Each tall crepe myrtle
has atlteast 20 suckers at the bottom. I know if I get rid of those
the tree will grow better. I keep cutting them and pulling them from
their root. But the roots are attached to the tree's roots. They just
keep coming back.

How does one keep the suckers away and maintain a clean look at the
base of the tree?

Thanks.