Planning the crop
Grapes require full sun and a soil that is free-draining but retains moisture, preferably a loam or even a gravelly soil. If possible, choose a site with a slight slope – a north-facing slope in areas with frost, as the leaves are frost-tender when they first emerge. The vine will need some form of support. This could be a pergola, a trellis against a sunny fence or wall, or a free-standing support of strained wires between posts, as in vineyards. Vines have an exceptionally long life, from 50 to 100 years or more, so it is crucial that the support is solidly built. Water should be readily available at the site because grapes need regular watering during their initial growth stage. Drip irrigation is ideal for vines. Overhead irrigation, especially when vines are fruiting, can quickly cause various fruit rots.
How much to grow- The coverage achieved by a vine varies according to the variety, but within five to eight years a single grapevine can cover a pergola 1.5 m wide by 4.0m long. Most vines take five to six years to come into full bearing.
Varieties- There are quarantine restrictions on the movement of grapes both between countries and also between regions to stop the spread of viruses, in particular phylloxera. Consult your local nursery for varieties best suited to your area. Some popular table grape varieties include Thompson Seedless (Sultana), Waltham Cross, Muscat Hamburg, Purple Cornichon, Ruby Seedless, Red Globe, Cardinal, Flame Seedless, Italia, Crimson Seedless and Blush Seedless. Isabella has long been a favourite in the subtropics, where grapes rarely flourish. This hybrid of the American Concord grape fruits reliably and is highly productive, with richly flavoured black grapes that are ideal for fresh eating and also make an excellent jam. Several grape varieties for wine are grown. But the best all-rounder, which is very adaptable to a wide range of districts, is Shiraz, as it is known in Australia, or Syrah, as it is known elsewhere. It is believed to have originated in Shiraz in what is now Iran.
It is important to prepare the ground well before planting a grapevine. Make sure the ground is free of perennial weeds. Work a small barrowload of well-rotted compost or manure into the soil and add a pelleted slow-release organic fertiliser. Grapes are planted between late autumn and early spring. If for any reason you have to delay planting bare-rooted vines, prevent the roots from drying out by covering them with damp sacking or a temporary cover of moist earth. If lifting plants from a nursery bed, lift them gently, keeping as much soil around the roots as possible, to avoid any setback or root damage. Any broken roots should be trimmed back before planting. European varieties derived from Vitis vinifera, the common grape, can be planted about 2.5 m apart. The stronger growing American varieties, such as Concord and its hybrid, Isabella, can be spaced 2.5–3 m apart. The less vigorous varieties, such as Cornichon, can be planted as close as 1.8 m. After planting, firm the soil down well around each plant and water in deeply to remove any air pockets. Keep the ground weed-free, particularly in the early years, as young vines compete poorly with heavy weed infestation. Once established, grapes do not need a lot of fertilising. An annual application of well-rotted compost or manure, ideally mixed with seaweed meal, should be adequate.