How much light do grapes need?

[SimonCole]

I have a Boskoop Glory, Van der Vroege (Dutch early), ornamental ‘Purpurea’ to go along my extension wall with a fig. All have been kept in pots thus far and I am keen to get them into the soil. The problem is that the wall only receives between 4 and 5 hours of direct sunlight, around midday. It is southern facing, but hemmed-in by buildings. Will this be enough light to ripen any fruit? How much light do your grapes get?

The other question I have been meaning to ask is how tall can you grow grapevines outdoors? The wall goes up over 20' and it would be good to utilise this space for growing fruit. Would an espalier arrangement be OK for this purpose?

Many thanks in advance for any help.

[Alison]

Have no idea what type mine is but know that they ripen up quite well with a similar amount of direct sunlight as you're talking about. They get plently of general light though.

The vine spreads pretty much as far as a let it, chopped it back excessively last year and it's bigger than ever now. Not sure how you'd manage an espalier type arrangement though, you certainly couldn't do it like my apple tree, the growth is too fast and vigorous. I know it varies with different varieties and it can take them a few years to become established though.

[rustylady]

I used to grow a grape vine in my greenhouse (a few years ago). The root was planted outside and the main stem led into the house. I trained it as an espalier and it worked very well. The only trouble with vines is that they put on so much growth you really do have to keep an eye on them and you seem to be constantly pinching unwanted growth. It would probably grow up your wall, but how would you be able to access for pruning/training?

[SimonCole]

That's good news... Thanks for both your help.
I'll have to have a bit of a think about the vigorous problem. I'm quite happy up a ladder, but do you think that planting grapes that close to the building could cause structural damage?

The other thing I'm a bit worried about is that I've read that if you prune grapes when they are growing, they can bleed to death. Does this mean that I shouldn't pinch out excessive growth in the summer?

By the way, how do I grow a two-tier espalier?

[littlemark]

The other thing I'm a bit worried about is that I've read that if you prune grapes when they are growing, they can bleed to death. Does this mean that I shouldn't pinch out excessive growth in the summer?

I've pruned no end of growth off my vines throughout the Summer, with no visible signs of death yet. Most commercial vine training systems involve a very heavy pruning back of most of the years fruiting canes at the end of the season. The next years grapes will be born on new fruiting growth from as little as one (more usually two or more) canes from the previous year. This heavy prune is usually done in the winter when the vine is fully dormant (Jan-Feb), and problems with bleeding can be encountered if this is left too late when the sap has started to rise. Even then, the bleeding is only likely to reduce vigour, certainly not kill the vine. Pruning out excessive growth through the Summer is perfectly normal and shouldn't present any problems.

Mark

[SueA]

Hi Simon, I have a grapevine growing outdoors over an arch in a South facing garden & it grows like wildfire & constantly needs trimming back during the summer. I think it depends on the variety how well they do outdoors & you do need a fair amount of sun to ripen the fruit, I think mine is possibly 'Brandt' or similar & is an outdoor variety. You should have enough light & as for the roots you could always keep it in a container sunk into the ground to contain it a little.Only pruning in early spring when the sap is rising as the leaves are just starting to break can lead to a lot of bleeding, you're fine doing it in summer. Remember you might need to protect the fruits from the birds , I usually lose loads to the local blackbird!

[roitelet]

When I had a vine I worked on the principal that for summer pruning, if the shoot snaped my fingers then it came off. I never actually cut anything in the summer, I left the cutting until the winter.

[SimonCole]

Thank you all for you help

I'll also remember to net.

[angelajnichols@hotmail.co]

I have just been given a vine as a present it is Uva Nera and I have no idea where I should plant it . give me a clue , please

[SueA]

Hi Angela & welcome to the vine, don't know much about 'Uva Nero' except it is an Italian red wine grape & likes a lot of sunshine so I would imagine it might need to be grown in a greenhouse over here unless you live in a very warm, mild & sunny part of the country. Hope someone else has a better idea about it for you.

[Rob G]

I've only just found this thread, so I will add my pennyworth somewhat late.

Greenhouse vines are typically grown on a single 'rod' - this is the main stem and can be quite long. Once the rod has grown to the limit of your GH, winter pruning when there is no sap around (this is the bit that everybody gets worked up about 'bleeding'), cuts out the old hard wood such that every 9" on the rod there is a short spur with 2 buds on it - short being in the order of 2".

Once these buds have started to grow, you can nip out any of this year's shoots, but not any of the hard wood from previous years. The aim is to have one side shoot from the rod every 9" or so, with the side shoot being around 18" long and carrying one large bunch of grapes.

If you don't want large bunches, then my mother's 'just-tidy-up' prune and let everything grow willy-nilly approach seems to work as well but the bunches are far smaller, but more numerous. As my mother is 88, this approach suits her better!

Rob