How you must grow gulmohar tree?

This tree (Delonix regia) is a tropical tree, requiring a frost-free climate, or at least one with VERY rare, short-term (hours only) freeze occurrences. If you don't live in zone 9b or warmer you will need a heated greenhouse.

Below are links to articles with info on growing this tree. The last link is one on the forests where this tree is native. Knowing the details of a plant's climate of origin can help you provide more exact care. It is native to Madagascar, which is just south of the equator.