The grape vine is one of the oldest cultivated fruit bearing plants, the fruit is not only fermented for wine, it can be dried and used in deserts or cakes. A wall covered with a vine in full leaf can make an attractive feature especially if you are growing the red leafed varieties. The ideal growing season for grapes would a long dry summer and a cool winter, they will tolerate frosts in the winter but spring frosts can kill new budding shoots.

Site and soil
Grapes can be grown be grown in the open as long as you choose a sheltered warm location. An ideal site would be on a gentle south or southwesterly facing slope, sheltered from the cool north and east winds. The rows should run north to south, this will ensure each plant has an even amount of sun exposure. Avoid frost pockets as a spring frost can ruin a crop. For cooler areas a south facing wall would make an excellent location.
Although grapes are tolerant of most soil types, a deep well drained medium loam would be preferable.

Erecting training wires

Training wires and post can be erected prior to planting the young vines, or at a later stage as they will not be needed for at least two years. The training wires are supported on posts, each plant will have it's own post. The post should be about 2 metres long and driven at least 50 cms firmly into the soil. Each post should be about 1.5 to 2 metres apart. Wires can then be attached to posts as in the diagram. Each row should be spaced about 1.5 metres apart.

The diagram to the left also shows the young vine planted and pruned to three shoots.

Training

There are many methods of training and pruning vines, all are based on the fact that the grapes are normally formed on current year's shoots growing from the previous year's wood. The method of training I am going to use is the Guyot method, to simplify things I will start from the first year of the vine being planted.

Planting (first season)

The best time to plant the young vines would be around October. Dig a hole about 60cm deep, if your soil has poor drainage apply a small amount of hardcore in the bottom. Cover the drainage material with some well rotted manure or compost and add some fertilizer such as bonemeal. Add a little amount of top soil and place the vine plant into the hole. Fill the hole with the remaining soil, afterwards firm the soil around the plant with your boots. After planting cut the stem back to three good buds. Finish the job with an application of mulch.

Second season

In the spring the three buds left on the plant from last October's pruning will start to grow into shoots. When the three shoots have grown to a height of the top of the post nip the grown ends out, these stem can be tied to the wires for support. If any fruit developes during the first year remove them from the plant. In October when all the foliage has died back, it will be time to prune once again. Cut one of the three stems back to three buds, leave the remaining shoots tied to the wires over winter.
This is illustrated below..

Third season

In early spring when the sap starts to rise tie the two main stems can be tied to the bottom wire. These tied stems will produce this years fruit, also side shoots will appear. Allow only 6 to 8 shoots grow, the remainder should be removed close to the stem. The growing shoots tips should be removed when they reach the top of the post. Also throughout this growing season the three replacement shoots will grow, these need to be cut when they reach the top of the post and will need tying to the wires for support.

Culture and care

I usually give the vines an annual mulch dressing in the autumn and in the spring a small application of poultry manure pellets. Watering of the vines is only necessary if there has been a prolonged dry spell, excess watering after the fruit has formed can cause the berries to split. The vines should not be allowed to bear heavy crops until after their fifth year. Thinning of about 50% the berries is advisable as this will improve the size and shape of the fruit. This should be carried out in two stages, first removing the poor ones first and later the overcrowded fruit.

Harvesting

Desert grapes are normally harvested according to taste, just take samples periodically during the autumn. Grapes for wine making should be left on the vine as long as possible, this will help them achieve a higher sugar content suitable for fermentation.