Akebia quinata not flowering

I planted an Akebia quinata 2 years ago on an east facing wall. It romped away pretty quickly and still seems very content.

However, as yet, although I've had lots of leaves and it's climbing rapidly, I've not had one flower.

Does it take a while to flower? Does it need a particular feed? I fed it poultry manure in early spring and been feeding it rose fertiliser every couple of weeks since.