Sick Bottle Brush - Help please

Callistemon laevis flowers twice naturally but mine usually gets hit by an early frost in October and burnt off. I have a collection of around 10 now but have given up on certain varieties as they are not at all hardy. I just prune after flowering if necessary, I don't think the smaller flowers are worth waiting for or worth the effort. I can't keep C. citrinus Splendens, White Anzac or Masotti, all died when temps went below -7c and being in a sandy frost pocket doesn't help.

 

I've just looked at mine and the flowers are starting to drop.
Looking at it I'm tending to think it's basically dead heading as close to the base of the old flower head as possible.

 

Hi @CarolineL now I'm not sure whether to ease of watering or water more? ‍♂️

However, is it the zoomed out pic of the aspect which you felt looked dry? If so that was taken a few weeks prior to us planting and the soil has been watered / improved with compost since then.