My New Pineapple Broom...???

I recently planted a Pineapple broom, and after a week have noticed that several of the leaves are turning yellow....... does anybody know why this may be so...... I live in an area where the soil is clay-like...... the only other thing that I have noted is that there have been ants noted in several of the flowers...... what is the best way to treat this ?????

 

The ants themselves wont do any harm, they may be just interested in the nectar in the flowers, or they could indicate green fly.
If the leaf loss is just older leaves, then I wouldn't worry too much, some leaves are lost from time to time.
pete