I have two beautiful ceanothus which have put on a marvelous disply this year and it would seem, attracting bees from miles around.
Mime, I would estimate to be at least 20 years old and still looking good.
When ever I've looked up on how to care for them, it usually states that they are drought resistant and pruning not necessary, therefore I've just left the alone to romp away.
I have however been toying with the idea of pruning back some lower branches, to make mowing easier, and as a rule of thumb, I would suggest pruning 'soon after flowering' so within the next couple of weeks, should be fine I m o.