Q.jacaranda tree
Our jacaranda tree has lots of green leaves, and appears health but has very few purple blossoms. what could the problem be?

Stop fertilizing grass growing near and under a jacaranda. The nitrogen found in lawn fertilizers can prevent trees from flowering.
Water jacaranda deeply with 1 or 2 inches of water, covering the entire area under the canopy. Do this once every two weeks from spring until fall, during the growing season.
https://www.gardeningknowhow.com/ornamental/trees/jacaranda/jacaranda-tree-information.htm