Champaca tree dropping leaves in Spring?

Is this normal? Or just shock from the hot weather?

Tree has been 2 years planted in ground. No flowers yet. Tree still look full despite dropping a ton of leaves. I've also plucked out several dead / dying leaves.

Also using the dropping / dying leaves as mulch.

edit: Champaca!

 

How was this planted? I'm wondering if there are different kinds of soil at work here.

 

its planted in sandy soil mixed with a bag of Dr Earth Fruit tree planting mix

 

Ah, have a read through this:

https://s3.wp.wsu.edu/uploads/sites/403/2015/03/soil-amendments.pdf

 

Thanks. To late to do anything now.

I've watered it with fish fertilizer and a dose of iron. Tree seems to be greening back up. Maybe it just need a ton of water.

 

Looks like it has made a comeback after the dose of fish fertilizer / iron. Watering it more often also since it's in the middle of the south facing yard. Gets afternoon sun all day.

It's a healthy shade of green now. Not as pale as before.