This kind of tree is quite popular in Vietnam as shade tree along streets. It seems the tree grows better and produces more spectacular blooms in hotter and more humid regions.
I have one in my cool garden. It's around 5 years old but remains quite small so I thought it doesn't like cool climate.
It's now blooming for the first time. The clusters of bloom are much shorter and the blooms are much smaller than those of the tree in my Saigon garden.
I am so happy that the tree finally adapts to its growing condition and blooms for me.