Massive Grapevine

[Bungee]

Dear all,

My father has a large grapevine that grows on a S.W facing, White, gable end wall of a bungalow, it grows right up to the roof top and around the corner of the building. It is at least 25 years old (I think) and has never produced any fruit larger than pea size bunches.

Is there anything that can be done to get it to produce a fully developed crop or is it too old, in the wrong location and too big?

Any advice would be greatly appreciated.

Whatever the answer it will remain as a decorative green climber!

[selfraising]

Wow that is big. I'm afraid I can't comment on the age of it as mine is only 5 years old. However, it does crop every year. When it starts to produce fruit, I cut out any new shoots to direct the energy to the fruit. Also when the bunches are pea sized you need to thin them out so that the fruit has room to swell. I also give mine a good watering when it starts to fruit and an occasional feed.

[FB.]

The white wall probably reflects a lot of the heat from the sun. It might also be that the variety is not suited to the UK. Maybe it was planted from a pip, so isn't a good-cropping variety.

My grapevine (Black Hamburg) grows against the SoUth-facing brick wall of my house with my tarmac drive below. The wall bricks are hot day and night.

[TonyF]

We've discussed this so many times here, it's in the archive. The time to prune the vine is in February/March depending on where FiL lives and don't be soft with it. Identify the main stems and cut everything back to the main stems, at that age they will be fine. That will stimulate the growth and it will grow back quite quickly and should fruit.

I have a huge vine, over the terrace, very sunny tho north facing, as old as FiL's and that's what we do with it every year so it's effectively a load of long sticks. This year we have the best crop of grapes we've had since we've been here. I wouldn't prune it at all when the bunches of grapes start to grow, just thin out those that are in the wrong place. The usual convention is no more than 2 bunches per shoot.

And harsh winters don't hurt them, often -8 or even -10 here for weeks on end in winter and it's still one of the best wine growing areas in the world.