Welcome to GoY, is this a newly planted shrub Iristia and, if so, have you been keeping it very well watered in this hot dry weather.

I bought the plant 4 years ago and it is being watered everyday...especially in this heat.

Then I don't have a clue... when you planted did you make sure the root ball was opened up?

Thank you for welcoming me to GoY Moon growe.

Yesterday I decided to dig it up and try and find out what was ailing the plant...and the root ball was in the shape of the pot it was grown in ...it was quite surprising.
It looks like that was the problem !

Thank you for your help in solving the problem

I assume you have teased the root ball out and replanted? If so keep very well watered and, if possible shade from the heat of the sun.

Many thanks.