My tree bloomed beautifully when we first planted it. It has not had any more blooms since then, which has been about three months. It gets plenty of sun and is well drained. I have watered it regularly.
Established plants will bloom in the spring and may bloom intermittently through the summer.
With your plant being newly planted, it is likely spending it's energy sending down roots.
You may have more blossoms and longer flowering period next season.