Propagation

Seed

Best sown in a cold frame as soon as it is ripe. Six weeks cold stratification improves the germination rate, and so stored seed is best sown in a cold frame as soon as it is obtained. Germination should take place in the first spring, but sometimes takes another 12 months. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in a cold frame for their first winter. Plant out in early summer.

Rooted cuttings

Cuttings of mature wood of the current seasons growth, December/January in a frame. These cuttings can be of wood 15 - 30cm long or they can be of short sections of the stem about 5cm long with just one bud at the top of the section. In this case a thin, narrow strip of the bark about 3cm long is removed from the bottom half of the side of the stem. This will encourage callusing and the formation of roots. Due to the size of these cuttings they need to be kept in a more protected environment than the longer cuttings.

 

Cultivation

Prefers a deep rich moist well-drained moderately fertile loam[1][18]. Grows best in a calcareous soil, but dislikes excessively chalky soils[18]. Prefers a pH in the range 6.5 to 7[18] but tolerates a range from 4.3 to 8.6. Succeeds in sun or partial shade though a warm sunny sheltered position is required for the fruit to ripen[18].

Very commonly grown in the temperate zones of the world for its edible fruit, there are many named varieties, some of which have been developed for their use as a dried fruit, others for dessert use and others for wine[19][5]. Good and regular crops are a bit problematical in Britain, grapes are on the northern most limits of their range in this country and the British summer often does not provide enough heat to properly ripen the fruit. Late frosts can also damage young growth in spring, though dormant shoots are very hardy, tolerating temperatures down to about -20°c[3]. Nonetheless, there are a number of commercial vineyards in Britain (usually producing wine grapes) and, given a suitably sunny and sheltered position, good dessert grapes can also be grown. In general it is best to grow the dessert varieties against the shelter of a south or west facing wall[20]. There are a number of varieties that have been bred to cope with cooler summers. Grapes are very susceptible to attacks by phylloxera, this disease is especially prevalent in some areas of Europe and it almost destroyed the grape industry. However, American species of grapes that are resistant to phylloxera are now used as rootstocks and this allows grapes to be grown in areas where the disease is common. Britain is free of the disease at the present (1989) and grapes are usually grown on their own roots. Plants in this genus are notably susceptible to honey fungus[18]. The flowers are intensely fragrant[21]. Grapes grow well in the company of hyssop, chives, basil and charlock[22]. They grow badly with radishes, both the grapes and the radishes developing an off taste[22]. Plants climb by means of tendrils[23]. Any pruning should be carried out in winter when the plants are dormant otherwise they bleed profusely[23].

The cultivated grape is thought to have been derived from V. vinifera sylvestris. (Gmel.)Hegi. This form has dioecious flowers and produces small black grapes.

Additional information for Grape