possible problem with callisteman citrinus splendens?

I plaanted a new bottlebrush shrub last April in one of the borders. It flowered ok but i have noticed the leaves are turning a pinky/red colour from the base. Is this wind or cold damage to the plant? It is planted facing a southerly direction so it gets plenty of sunlight and the soil is a good loam. There is a 3 foot high wood panel fence to the rear of it that was put in a few months before it was put in. Any ideas?

 

Strongylodon is the expert on Callistemon he will probably know.