Your vine, planted in a garden, may be there for more reasons than just producing grapes: it may be for shade, to fill a gap, to screen a fence but these notes are all about grapes. The key to producing a really good crop of grapes year after year is the right care and attention in the vine's first few years — then subsequent correct pruning.
Where to Plant?
Vines need sun and, in the UK, the more the better so plant for maximum sun exposure. Vines are not very fussy about soil — most soil types will do — but the soil does need to have reasonable drainage. Vines won't thrive with their roots permanently waterlogged. When a new vine is trying to establish itself, it is not very good at competing for water and soil nutrients with other plants so don't put it in a crowded area of the garden.
If your ground is light and liable to dry out, plant deep (200mm or eight inches at least); if it is the opposite, plant shallow (but not less than 50 mm or two inches) and even consider raising the ground by 150mm (six inches) or so and plant in this. If you have wires in place fix the vine to the wire; if you intend to use a cane to support the young plant, put it in the hole first then arrange the plant roots around it. Do not add fertiliser to the planting hole. The aim is to encourage the roots to go and look for water and nutrients not to laze around where the living is easy. Finally, back fill the hole and firm as you go.
Early spring is the best time to plant — it is when the vine is beginning to grow and put down roots so it gives the vine the best chance to establish itself and flourish.
Protection — in the first year or two it is a good idea to protect your vine with a simple cylindrical plant guard, just a loose-fitting plastic tube, which will protect the young shoots from damage caused by pests, the weather and accidental breakage.
Watering — vines are pretty tolerant of dry conditions when they are well established but young vines do need watering during the growing season. To get good root development, you want the roots to grow downwards (may sound obvious) but if you give your vine lots of light watering it will encourage roots to grow near the soil surface so a better strategy is to give the vine fewer heavier soakings and this should encourage deep roots.
Nutrition — vines will grow in all kinds of poor soils and have pretty low nutrition needs. A small amount of organic matter can be added to the soil at the start of every growing season but overly fertile soil is not good for vines as it encourages too much growth that is detrimental to a vine's ability to produce fruit.
Vines are large plants and some kind of support needs to be put in place. You may not need much more than a stake in the first year or two but remember that vines are incredibly vigorous and, as they grow, they will need space and support. A pergola is ideal, and another good support is to fasten vine eyes to the wall with rawl plugs. Use thick wire — not the thin stuff — and tighten this between the vine eyes in horizontal rows. Don't allow your vine to grow behind drainpipes or guttering; it will get very heavy and can pull them away from the wall.
The first year is all about establishing the roots and, in order to establish a strong root network, the vine needs to produce a good amount of foliage in its first two years, the two issues are closely related. You need to remove any bunches of grapes before they start to develop — all the vine's energies need to go into producing foliage and roots.
The other priority in the first few years is the establishing of a trunk. This will give the vine the basic structure you want and it is also where the vine stores lots of the carbohydrate needed to support the growth of the vine.
In the second year is about not allowing any fruit to develop; it may seem frustrating but it will give you a stronger, more productive vine. During the growing season if growth is getting out of hand, and some vines are amazingly vigorous, you can cut and trim your vine without doing it any harm. If the trunk is well established, cut it back so that it has just two canes coming off it, both cut back to two buds. If the trunk is not well established, prune the strongest cane back to two buds and remove everything else.
In the third year let your vine produce some fruit; the crop will probably be small but it will be the promise of bigger things to come.
Pruning mature plants, and those over three years old
The most important job of the winter is PRUNING. Not many of the urban grower's vines will look like those grown in neat lines in vineyards across the world and so it may be hard to make sense of pruning diagrams.
A vine will grow up to 6 metres or 20ft in a year and they love to climb and put out side shoots, so pruning and trimming will need to carry on throughout the growing season although the most important and radical prune will be in the winter. Because vines are notoriously hardy, they can be brutally cut back — in fact up to 90% of the vine can be removed so don't be afraid if you go mad with the secateurs; mistakes can usually be rectified the following year. The aim of pruning is to achieve a balance between fruit and foliage and, in your urban garden, foliage may well be important to you. However, if you want lots of foliage, you will compromise the quality and quantity of fruit.
In the winter (between December and March) you should cut back all of this year's growth to 2-3 buds, or a few inches of shoot. Don't leave any long canes. Try to establish a framework of short side shoots emerging from the main trunk and thicker branches. This is called spur pruning.
As the grapes start to form on the vine, you should cut back the leaves which are shading them out and will prevent them from ripening. You can cut back the shoot growing beyond the bunch of grapes as this will keep the plant's energy for ripening them. Also remove any new shoots not bearing fruit back to few inches long.
This is basically spur pruning again, this time back to the fruit. This may have to be done again before the grapes are harvested. June and August are good times to cut back the leafy growth.
Make sure your secateurs are sharp. You can damage and tear your vine with a blunt blade!!
Don't worry about the cold as vines are pretty hardy and, while they are dormant, a London winter shouldn't do them any harm. Temperatures need to be very low (-15°C) to do real damage.
To Feed or Not to Feed
Grapevines are tough and vigorous and they grow in some pretty barren places and therefore don't need much in the way of nutrients. You could give your vine a small amount of organic mulch but, if the soil is very fertile, it will encourage lots of foliage growth that is not necessarily the best thing for growing good grapes. You do not want to encourage a crowded canopy as grapes benefit from some direct sun and some air circulating round them.
Remember that top vineyards like to subject their vines to some stress (low level nutrition and water) as this produces the best quality fruit.