Growing Grapes: In the Open Garden

Grapes have been successfully grown in Britain since Roman times and the Domesday book records that 38 vineyards existed in 1088. It is commonly assumed that grapes are difficult to grow in the open and that they will ripen only in favoured sunny summers. This is no longer the case.

South of a line from the Wash to Worcester and taking in the Welsh counties bordering the Bristol Channel, (less so in Pembrokeshire), and the English counties east of Devon, full success can be expected in about seven years out of ten and ripe fruit, albeit of lower quality, in other years. Success does, however, depend on four requirements being met. Four essential requirements Firstly, choose a reasonably favourable site in order to achieve a good micro-climate within the ‘vineyard’; thus ensure that the site is not unduly shaded from the sun but has some shelter from the wind.

Secondly, select varieties which are early ripening, and which are immune or resistant to mildew. The varieties listed here have been selected to meet these requirements.

Thirdly, the vines must be managed and trained in the manner described below.

Finally, protect the vines from birds well in advance of fruit maturity.

Site

During the growing season vines respond positively to warmth and sunshine; at temperatures below 10°C (5o°F) development slows markedly. In this connection the majority of modern gardens are, because of their proximity to the house or adjacent trees and hedges, provided with some shelter from wind and shading from direct sunlight for varying parts of the day. Preferably, the site for the mini-vineyard should be exposed to sunlight for most of the day, but if some shelter from wind is available this is likely to prove a positive advantage even if some shading is caused. Shelter which does not unduly shade will help create a microclimate in which air and soil temperatures are higher because of reduced wind speed. Windbreaks can of course be provided for the vineyard, either in the form of fine mesh netting or as hedges.

Very favourable sites are afforded by brick walls and to a lesser extent by board fences. South facing walls are best, but those with easterly or westerly aspects are not to be despised. On such sites, film plastic sheeting can be rigged up to provide conditions which approximate a lean-to glasshouse. Dessert grapes can be the first choice for prime sites such as these.

Soils and nutrition

The first and most important consideration is that vines grown in the open should not be encouraged to make excessive vegetative growth. If they do, they exhibit a tendency to late ripening and proneness to attack of the fruit bunches by Botrytis (grey mould). Hence deep and fertile soils, such as those that produce lush crops of vegetables, should be manured with care and excessive applications of nitrogen avoided. Vines do, however, benefit from generous applications of nitrogen for the first two years or so of their life.

Almost any type of soil that is adequately drained can be made to grow good vines, given sound management. This applies even to chalk soils, including relatively poor and shallow ones. Sandy, gravelly and loamy soils are usually very suitable. Heavy clays, especially if poorly drained, are the least suitable but even gardeners endowed with such soils should not be deterred. Given care in establishing the young vines – putting a good supply of compost or peat in the planting holes – the vines will eventually grow freely.

One aspect of the nutrition of vines should be emphasized. They are very sensitive to a deficiency of magnesium, which manifests itself in the form of an interveinal yellowing of the older leaves of the current season’s growths. The first symptoms may be expected from midsummer onward and, if severe, will progress to a dessication and premature shedding of the affected older leaves. The symptoms should not be confused with lime-induced iron deficiency – caused by an excess of lime. The symptoms in these cases would be seen in the youngest leaves, including the growing point. But the varieties listed later are pretty tolerant of high lime. Curative measures for magnesium deficiency may require the application in early spring of up to 250 g per m2 (8 oz per sq yd) of agricultural Epsom Salts. On soils prone to the trouble, an annual topping-up of 100-125 % per m2 (3-4 oz per sq yd) may be required.

Routine manuring should include a constant supply of nitrogen, potash and phosphate, and on markedly acid soils an occasional dressing of lime. If available, applications of well-decayed compost or farmyard manure will be beneficial. Fresh animal dung should not be used.

A compound fertilizer at 250 g per m2 (8 oz per sq yd) should prove an adequate annual dressing. ‘Growmore’ fertilizer would be suitable and is best applied in late winter or early spring. Should a need for more nitrogen be indicated by lack of plant vigour and paleness of the foliage, a dressing of sulphate of ammonia or nitro-chalk can be given, either at the time of the main application or during the growing season.

Varieties

The varieties now listed have been selected for their ability to reach maturity even in adverse summers. All are suitable for making wine (Muller Thurgau and Siegerribe may also be used as dessert grapes) and are tolerant of high lime levels, such as occur in chalky soils.

Seyve-villard 5-276 is a hybrid now popularly known as ‘Seyvel Blanc’. It is an exceptionally reliable variety both in crop yield and ability to ripen. Its vigour is only average, which makes it easy to manage. It is resistant to mildew and grey mould.

Ripening from the end of September to mid-October, depending on season, it produces a white wine of very fair quality which can be further improved by blending with juice from the Muller Thurgau variety. It is not suitable for dessert. Midler Thurgau – also known as Riesling Sylvaner – is of Swiss origin and is the variety most extensively planted in British commercial vineyards. It is also widely grown in Germany. Unfortunately, it is prone to attack by downy mildew in seasons when the weather is adverse.

A most excellent wine variety, it is also very acceptable for dessert provided the berries are thinned soon after fruit set.

Siegerribe

This variety is German in origin. The golden berries are suitable for either dessert or wine, and have a distinct muscat flavour.

Madeleine Angevine

This early-ripening, well-flavoured, white grape is suitable for either dessert or wine. Tereshkova Few black varieties are suitable for dessert when grown in the open in the U.K. But this red variety, sporting a purplish bloom, is early ripening and attractive for dessert. It is of Russian origin, obtained by hybridizing with a Siberian grape.

Siebel 13053—now known as Cascade—is proving one of the most prolific and reliable black grapes for wine. Of German origin, it produces large numbers of laterals, which carry a profusion of relatively small bunches. To obtain full yields more fruiting laterals should be retained than for other varieties. Used unblended it produces a red wine of brilliant colour and it is also useful for blending with wine from Baco No. 1. Baco Because of its rampant vigour this variety is not usually recommended and if planted in a row will require a spacing of at least 3 m (10 ft) and a modified renewal or spur system of training. It will readily cover a large wall or fence. A prodigious cropper, it will ripen every year provided that it is netted for bird protection and, in cold summers, left to mature on the vine until late October or early November.

Gagarin Blue is a black wine grape from the same Russian source (the Caucasus) as Tereshkova. Some are critical of its large and straggly fruit bunches; many flowers fail to set but the remainder grow to become large berries with a high ratio of pulp to pips. The yield is at or above average and it never fails to ripen by September.

General management

Planting: One-year-old plants establish most successfully, and should be planted in the spring, although this can be done in the autumn. Vines are propagated either from hard wood cuttings or by grafting on to the root system of North American varieties immune to root aphid. Either method is suitable for growing grapes for wine in British gardens. Pot the young plants in a compost such as John Innes No. 1 in 15-cm (6-in) containers. They can then be set out in the open ground quite late in the spring their permanent positions. This will avoid the risk of damaging the one-year-old canes.

The method of pruning best suited to producing grapes in Britain is the Guyot system, for which the following arrangement of posts and wires has been carefully designed.

Each post should be about 2 m (6 ft) long, driven firmly 50 cm (20 in) into the ground.

Intermediate posts should be placed 3 m (10 ft) apart. Posts at the end of long rows will need support in the form of struts.

Four levels of 12 gauge wire are attached to the posts. The first and lowest wire, a single strand, is 45 cm (18 in) above the ground. The second wire, consisting of two strands 2.5 cm (1 in) apart, is set 22 cm (8-1/2 in) above the first. The third wire, again a double strand, is set 30 cm (12 in) above the second. The two strands of the third-level wire are held 30 cm (12 in) apart horizontally by spacer bars attached to the intermediate posts. A final wire of two strands, arranged exactly as the third-level wire, is set 30 cm (12 in) higher than the third, that is 127 cm (5 ft) from the ground.

Without check: Alternatively the vines can be purchased already growing in containers.

If you are growing several vines, space them 1.5 m (5 ft) apart, with 2 m (6 ft) between the rows. Very vigorous varieties, such as Baco No. 1, will need more space.

Fill the planting holes with composted vegetation, peat or potting soil. Spring-planted vines will need watering until they are rooting freely.

Staking

While a support system for the vines can be put up any time in the first year, consider doing so before putting the young plants in

05. June 2013 by admin
Categories: Tips and Advice | Comments Off on Growing Grapes: In the Open Garden

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