The focus is somewhat out, but there's just enough detail to see the
very finely bipinnate foliage characteristic of Acacia dealbata. The
silvery stems and young shoots give it away, even if impression is of
the plant being greener than that species normally appears. Regular,
hard pruning would account for this in any case and the op writes it
is pruned back by 6ft. every year. If major pruning is carried out at
any other time than immediately after the normal flowering period,
then there will be few or no flowers for the following year. I
suspect this is hard pruned in summer/early autumn, hence no flowers
being reported. If pruning is carried out in March, then the ensuing
growth will have the opportunity to ripen and develop flower buds,
which will open during late winter/early spring of the next year.
Left to its own devices, this tree would be a mass of brilliant yellow
in December, January or February each year.