Nick Maclaren wrote:

I'm sure it can cope with winter cold, but it needs lots of summer heat if it is to perform well. This year we had plenty of that and the Lagerstroemia responded accordingly.

Aargh! YOU may have done, but most of the country didn't!

Yes, July was unusually hot and dry, but it was wet and gloomy from
the beginning of August onwards - none of my vegetables that need a
decent late summer did at all well. And, here, it wasn't warm enough
to get plants to cropping state by the start of July :-(

I'll try not to rub it in Nick, but we had magnificent weather right
through. Even August was pretty good, although not as good as June and
July, which I'm sure spoilt everyone's expectations. Most of the rain
and grey stuff seemed to be shunted north and east ... possibly in your
direction?

Not all parts were as wet, but most were as gloomy. Yes, it was warm,
but warmth and sunlight aren't the same, and there wasn't a single
HOT day after the end of July :-(

We had 12 days above 30C in July and only 3 in August, so by that
definition it wasn't as hot. However the number of days above 24C was
about the same and night time lows remained as high. As to rain, we
did have some, but we also had a fair amount of sun - just about
average for this region in August. It was enough to persuade my clump
of Crinum moorei to produce a second crop of flower spikes, which gave
a wonderful repeat show in September. Many of the South African
succulents (Lampranthus, Delosperma etc. also gave a good second show
towards the end of August and a climbing Aloe (A. ciliata) was
persuaded to produce again, festooned in spikes of vivid scarlet
'cigars', by early September.

Let's see if my Albizia keeps its new growth through the winter.

Depends upon how long it gets before the first hard frosts. A wet or
dull end to summer means that the shoots don't harden as well as they
might. Hot dry Augusts and Septembers are best for that. A long, slow
build up to the cold weather can help, fingers crossed eh?