Allotments 4 All

Anyone know when this is supposed to flower? I have six plants that have formed an impressive 6 1/2 " giant intertwined upright vine in the garden, but not a single flower yet.  ???

Soon if this good weather holds... these half hardy climbers, I'm a morning glory fan, do require a time between planting out to flower... it is only the start of August and some years my MG don't flower until Sept.!
:o