Gardening

Which is a Japanese variety of crape myrtle as opposed to the more common lagerstroemia indica.

Lagerstroemia fauriei grows in the Southern zones, is more tree like, and generally doesn't bloom as abundantly as does lagerstroemia indica which is why the latter is often preferred in the US. As with all crape myrtles, it will bloom best if selectively pruned in the winter or spring and appropriately fertilized prior to blooming, which will probably be in the mid to late summer.

If these were mine I would prune them into one or two strong trunks and just enjoy them as a stately tree with an attractive trunk. Since they are mature, they may never bloom all that much.

http://hort.ifas.ufl.edu/database/documents/pdf/tree_fact_sheets/lagfaua.pdf