Outside our back door we have a grape vine growing and each year it has fruit begin to form. Yet they don't swell as the summer goes along so we don't get fruit from the plant.
So this year I'm going to try something my mum used to say.
Feed the flower, not the leaves.
So rather than just cutting back the vine as it starts to take over every few weeks I'm going to keep cutting back on the new shoots to see if I can get the grapes to swell. As you can see in the photographs the vine has a lot of grapes ready to swell, if this works come the autumn we could have plenty of bunches to harvest.