My crepe myrtle aren't blooming very much, how can I amend this?

they are growing bigger, they just don't bloom like others in the areaMy crepe myrtle aren't blooming very much, how can I amend this?
Some thoughts from a crape myrtle site:





Light Requirement


For strong growth and abundant flowering, plant crape myrtle in full sun. Heavy shade will reduce growth and flowering and will increase disease problems such as sooty mold on the foliage and powdery mildew on the flower buds and young growth. Large shade trees will also compete with the crape myrtle for moisture, causing poor growth and flowering. Lack of sunlight and moisture are the common causes of poor growth and flowering.





Pruning


Crape myrtle flowers on new growth of the season, so you can prune plants any time during the late winter or early spring before growth begins without loss of flower buds. Avoid pruning in early fall before the first frost, because pruning forces new growth and keeps the plant from going dormant. Severe freezes can kill the plant if it is not fully dormant.





If you want a tree, cut out all except one to five branches at ground level. Remove all side branches up to the level where you want the limbs to start.





Pruning results in an abundance of new shoots that form flowers. It also reduces the amount of vegetative growth and funnels the energy of the plant into new growth and flowers. Pruning, however, is not essential for flowering. Some of the most spectacular floral displays can be seen on old, unpruned crape myrtles along roadsides. Flower clusters are usually smaller on unpruned crape myrtles, but the number of flower clusters is greater. Therefore, the overall floral impact of the plant is not reduced.





Check the site for more info. Good luck!My crepe myrtle aren't blooming very much, how can I amend this?
Besides pruning-as suggested . . .





Fertilize with ';super phosphate'; or any other fertilizer with a high middle number, phosphorous improves bloom in woodies.





Rick ~30yrs in profession
Are they getting enough sun? Crepe myrtles need almost full sun in order to bloom, or least the afternoon western sun. If it's not too big, I would move it to a sunny area. Good luck!