In their first year, water grapevines before the onset of drought. Indoor grapes will need careful watering, but outdoor-grown grapes will only need watering in severe and prolonged dry spells.
Remove all flowers for the first two years after planting.
Allow three bunches of grapes on three-year-old vines and about five on a four-year-old vine – slightly more if growing well. Allow full cropping thereafter.
Mulch in spring when the soil is moist, to suppress weeds, placing stones or gravel, 5-7.5cm (2-3in) deep around the base of the plants. White gravel reflects sunlight into the canopy of the grapevine; black gravel or recycled slate absorbs sunlight, warming the soil. Do not use manure.
Read more information on cultivating outdoor grapes in our advice profile.
Ventilate the glasshouse or conservatory on bright days during spring and summer and ‘damp down’ the floor, except during flowering or when the fruit are ripening.
Pollination needs a dry atmosphere. Gently shaking branches aids pollination.
Water frequently during the growing season, and feed with a high potash liquid fertiliser (such as tomato feed) once growth starts in spring.
Use scissors to thin the bunches, usually one in three grapes per bunch, this improves ripening and air circulation. Special scissors can be bought for this purpose. Outdoor wine grapes do not need thinning. Check grapes two-three times a week and remove any that are diseased or damaged.
Do not heat the greenhouse and ventilate freely in still, cold dry weather until early spring, as dessert grapes need a period of dormancy. Place potted vines outdoors in winter to get sufficient cold.
In September, gradually remove the leaves to expose the branches to sunlight and improve air circulation.
Read more information on cultivating grapes indoors in our advice profile.
Pruning and training grapes
Install a supporting system: for vines against a wall space wires 25-30cm apart (10-12in).
For vines in open ground: drive 1.92m (6½ft) stakes, 60cm (2ft) into the ground, 3-3.6m (10 -12ft) apart; wire should be at 30cm (12in) spacing.
The main pruning time is early winter (late November - December). Training and pinching out of new shoots, as well as fruit thinning, takes place in spring and summer.
We have more advice on pruning and training grapes and on the various methods of training grapevines.
Read more about the Guyot system, where young fruiting growth develops from one or two horizontal arms.
The rod and spur pruning system, often used for grapes growing indoors or against walls outdoors, is also called the cordon system. Read more information on the rod and spur system, (also called the cordon system) where fruiting side shoots grow from a main vertical stem, like an espalier.
The main pruning time is early winter (late November-December).
Training and pinching out of new shoots and thinning of fruits is carried out in spring and summer.
There are two basic types of grapes - dessert and wine.
Dessert grapes need to be grown in a greenhouse to ripen properly or, if planted in a container, grown in a conservatory and put outdoors in winter. They can also be planted outside with the trunk and stems trained inside (as at Hampton Court Palace). Vines grown this way rarely need extra watering and are easy to feed and manage. Grapes do best at about 16°C (61°F) from early spring.
Wine grapes are grown outdoors, in a warm, sheltered, sunny site, such as a south- or southwest-facing wall or fence. Grapevines grow on any soil, providing it is well drained.
When planting a row of vines, a south-facing slope is desirable with the rows running north to south. Avoid frost pockets - frosts damage young shoots. Choose a variety to suit your climate and soil.
Buying and planting
Do not buy plants that are ‘pot bound’ (with a mass of roots running round the inside of the pot). If buying in summer, the foliage should be healthy green, not yellow.
Dig over the soil, break up any compaction and enrich borders, especially those for indoor grapes, with compost or fertiliser.
Ideally plant between October and March, in weed-free ground. Plant vines against walls and fences 1.2m (4ft) apart and 12.5cm (9in) away from the wall.
Plant vines in the open 1.2-1.5m (4-5ft) apart in rows 1.5-1.8m (5-6ft) apart.
Glasshouse red spider or two spotted mite
Leaves become mottled, pale and covered in webbing, on which the mites can be clearly seen; leaves also drop prematurely.
They thrive in hot, dry conditions, so mist plants regularly. Use biological control in the greenhouse.
More info on Glasshouse red spider or two spotted mite
Small creatures covered in a white ‘meal’ cluster in inaccessible spaces like leaf joints or under loose bark. They suck sap and secrete ‘honeydew’ which causes black sooty mould on the leaves.
Use biological controls and encourage ladybirds.
More info on Mealybug
A usually grey, fuzzy fungal growth which can begin as pale or discoloured patches. Grey mould ( botrytis) is a common disease especially in damp or humid conditions. Spores enter plants via damaged tissue, wounds or open flowers. Mould can also damage ripening fruit such as strawberries. Black resting spores survive over winter.
Remove damaged plant parts before they can become infected. Cut out infected areas into healthy tissue and clear up infected debris. In greenhouses, reduce humidity by ventilating and avoid overcrowding of young plants and seedlings.
More info on Grey mould
Appears as a white powdery deposit over the leaf surface and leaves become stunted and shrivel.
Keep the soil moist and grow in cooler locations.
More info on Powdery Mildew
Grapes are ready for picking when they feel soft to the touch and taste sugary. The skins on white grapes often change from deep green to a translucent yellow and become much thinner. The best way to tell when grapes are mature is by tasting them – only when they’re at their sweetest, will they be ready.
Cut them in bunches with the stalk still attached.
Dessert grapes are best eaten as soon as possible after harvesting, but they will keep for about two weeks if stored in the fridge.
Although wine grapes can be eaten fresh, they are better when pulped and made into wine.
‘Boskoop Glory’ AGM
Boskoop Glory is a good outdoor black grape suitable for both wine and dessert. Boskoop Glory is reliable, didease resistant and has a moderately good flavour.
‘New York Muscat’ AGM
New York Muscat is a black dessert Muscat grape which has a blackcurrant flavour. This grape is disease resistant and best grown on a warm wall to achieve full flavour.