Is it in a pot or in the ground? How much sun does it get?

It is in the ground & gets fullsun for about 6hrs in the afternoon

Any chance you could take a photograph and post it on here, Johnone? If not, I'd ask if its planted close to a wall or a fence and if it is, how close is the base of the plant to the wall? How tall and wide is it now and does it have plenty of healthy looking leaf and stem growth?

Close to fence (in a corner) about 5ft 6ins tall & 3ft 6ins wide plenty of healthy leaf & stem growth but slower growing than i expected.

They aren't the fastest growers, it's true. Sounds as if the plant is perfectly healthy, and not suffering from drought. Might just be that it's not warm enough for it to set flowers, but try a dressing round the roots of sulphate of potash now, raked or turned into the soil. Keep it watered during dry spells if necessary.

thanks