How to make grape vines bear fruit

Grapevines thrive in warm sunny locations with free-draining soil. Attractive as well as productive, they can be trained along walls or fences or over pergolas. Wine varieties should fruit successfully in milder areas, while sweeter dessert grapes are best grown in a greenhouse for better and more reliable fruiting, especially in northern regions.

  • Harvest grapes
  • Tie in and pinch out shoots
  • Thin out fruit
  •  


Water newly planted grapevines regularly throughout the growing season to help them settle in.

Although established vines are fairly drought tolerant, they can suffer from the fungal disease powdery mildew if too dry at the roots. To prevent this, water thoroughly every seven to ten days during the growing season, especially in dry spells in spring and summer.

Greenhouse vines with their roots inside the greenhouse need more frequent watering than vines with their roots outside. 

Mulching

With outdoor vines, it can be beneficial to lay a gravel or stone mulch around the base of the plant in spring. Apply when the soil is moist, in a layer 5–7.5cm (2–3in) deep. White gravel reflects light up into the canopy of the grapevine, while black gravel or recycled slate absorbs sunlight, warming the soil. The mulch will also suppress weeds. 

With greenhouse vines, mulch the rooting area with well-rotted manure just before growth starts in spring. Then, during summer, it’s a good idea to mulch greenhouse borders with straw to keep the atmosphere dry. This will aid pollination of the flowers and subsequent fruit set.

Feeding

Just before growth starts in early spring, feed grapevines with a high potassium general fertiliser, such as Vitax Q4. Scatter half a handful per square metre/yard around the base. Alternatively, sprinkle the root area with John Innes base fertiliser and dried blood at a rate of 120g (4oz) per square metre/yard. During the growing season, vines benefit from an occasional extra sprinkling of dried blood at 30g (1oz) per square metre/yard.

With greenhouse/dessert grapes, start feeding a month after growth starts in the spring with a high potassium liquid fertiliser, such as tomato feed, every two to three weeks. Once the vine is in full leaf, increase this feeding to weekly intervals. Stop feeding when the grapes start to ripen and colour up, as extra feeding at this time may spoil the flavour of the fruit.

Removing flowers and fruit

Remove all flowers for the first two years after planting, so all the plant's energy goes into getting well established.

Then allow only three bunches of grapes to grow on three-year-old vines, and about five on four-year-old vines – slightly more if the plant is growing well. Allow full cropping thereafter.

With dessert grapes, it is best to thin out the fruits within each bunch, to produce better quality grapes (see Extra care for greenhouse grapevines, below). The fruits of outdoor wine grapes do not need thinning.
 

Extra care for greenhouse grapevines

Ventilation and temperature

Grapevines like well-ventilated, warm, dry conditions. Although keeping the vents closed would raise the temperature, it would also increase humidity, which encourages fungal diseases and hinders pollination. So it’s best to keep the vents open during summer and autumn, especially around flowering and fruiting time. Some varieties, such as ‘Muscat of Alexandria’, benefit from extra heat, so for these place a small fan heater in the greenhouse in spring (to aid growth) and in autumn (to aid fruit ripening). In September, gradually remove the leaves to expose the branches to sunlight and improve air circulation. In winter, don’t heat the greenhouse and do ventilate it freely in still, cold, dry weather until early spring, as dessert grapes need a period of cold to induce dormancy.

Aiding pollination

Greenhouse grapevines may need help with pollination as there are fewer natural pollinators indoors. During flowering, at midday on a sunny day when the atmosphere is dry and the greenhouse is well ventilated, either shake the stems briskly but firmly, or stroke a cupped hand over each bunch of flowers, to transfer pollen between them. The latter is a more reliable method for early season Muscat-type grapes, where pollination can be temperamental.
 

Thinning dessert grapes

The size, sweetness and quality of dessert grapes are improved by reducing the number of fruits within each bunch. Thinning the fruits also encourages even ripening and better air circulation, which discourages fungal problems.

Thin twice, first when the grapes are tiny and again when the grapes have increased in size. Use scissors to thin the grapes – ideally vine scissors, which have long, narrow blades (available from some garden centres and mail-order suppliers). Steady the bunch with a small forked stick when thinning, as using your fingers spoils the bloom on the skins.  Remove about one in three grapes per bunch. Bunches can also be shaped while thinning – aim to produce a perfectly proportioned conical bunch. Afterwards, check the grapes two or three times a week and remove any that are diseased or damaged.

Removing tendrils

Tendrils are thin, twisty stem-like structures that curl around supports to allow the vine to scramble and support itself. Remove these as they form, as they will only get tangled up with the fruits and allow the vine to scramble rather than sticking to your pruning and training regime. Diverting the plant’s energy reserves away from tendril production will also leave more energy for fruit production.
 

Pruning and training grapevines

Grapevines are vigorous plants and if left to their own devices will soon outgrow their bounds, producing lots of lush leafy growth. So to keep them in check and maximise fruiting, they need to be trained on supports and pruned carefully. 

Grapevine are usually supported on a system of horizontal wires, either attached to a wall or fence, or to large, sturdy posts: 

  • For vines against a wall/fence, space the horizontal wires 25–30cm apart (10–12in).

  • For vines in open ground, insert 2m (6½ft) posts, 60cm (2ft) into the ground, 3–3.6m (10–12ft) apart. The horizontal wires should be spaced 30cm (12in) apart.

The main pruning time is early winter (late November to December). Training and pinching out of new shoots, as well as fruit thinning (see above), should be done in spring and summer.

In gardens, the most widely used pruning/training systems are:

  • rod and spur system (or cordon system), where fruiting side-shoots grow from a main vertical stem, like an espalier. This method is often used for grapevines growing in a greenhouse or against a wall outdoors

  • Guyot system, where young fruiting growth develops from one or two horizontal arms

  • Standards – vines in pots or where space is limited can be pruned and trained as standards, with a tall clear stem and a rounded head, like a lollipop

For detailed advice on these pruning and training methods, see our guide to pruning and training grapes.
 

Propagation

Vines can be propagated from hardwood cuttings in late autumn or winter. Softwood and semi-ripe cuttings can also be taken from late spring to mid-summer. Grapevines sold commercially are often grafted.

Named grape cultivars will not come true to type from seed, so seed propagation is best avoided.

There are two basic types of grapes – dessert grapes for eating, and wine grapes, although some varieties may be suitable for both.

  • Dessert grapes are sweeter and need warmer temperatures to ripen properly, so for a successful crop they generally need to be grown in a greenhouse in the UK

  • Wine grapes can be grown outdoors in milder areas of the UK, but will crop better under glass

Within each category, there is a choice of varieties, offering white, red or black fruits, seeded or seedless, with different flavours, levels of sweetness, hardiness and resistance to disease. Take care to choose a variety to suit your climate and soil. Look in particular for those with an RHS Award of Garden Merit (AGM), which shows they performed well in trials – see our list of AGM fruit and veg. Grapevines are usually sold in containers, as young plants 60cm (2ft) tall or more. They are widely available for most of the year in garden centres and from online suppliers.  If buying in person, check plants to ensure they are healthy – if buying in summer, the foliage should be green, not yellow. Avoid plants that are ‘pot bound’ (with a mass of roots running round the inside of the pot).

Where to plant

Grapevines can generally be grown outdoors in southern Britain, south of a line between Pembroke and the Wash, but it’s worth experimenting with growing north of this line, especially in western areas influenced by the Gulf Stream or in sites protected by a warm wall. Use later-flowering cultivars in northern areas. With rising temperatures due to climate change, the range of growing sites is ever expanding.

All grapevines should be planted at the base of a sturdy system of supports – usually horizontal wires attached to a wall or fence, or to sturdy posts, at least 2m (6½ft) tall. The wires should be spaced about 30cm (1ft) apart. For more details, see our guide to pruning and training grapes.

 

​Wine grapes can be grown outdoors in a warm, sheltered, sunny site, such as against a south- or southwest-facing wall or fence, especially in milder parts of the UK. They do best in locations where temperatures are about 16°C (61°F) from early spring. â€‹Avoid frost pockets, as frosts can damage the young shoots in spring.

They can be grown in any soil, providing it is well drained. Sandy gravel over chalk is ideal. Improve drainage on heavy soils by adding well-rotted organic matter and grit. Install a drainage system if necessary. A pH of 6.5-6.8 is required, so lime acid soils to raise their pH.

When planting a row of vines, a south- or southwest-facing slope is desirable, with the rows running north to south.

Dessert grapes generally need to be grown in a greenhouse to ripen properly in most parts of the UK, although some varieties can be grown outdoors in very warm, sheltered spots. When growing under glass, they can either be planted in a greenhouse border or just outside the greenhouse with the trunk and stems trained inside (as at Hampton Court Palace). Vines grown this way rarely need extra watering and are easier to feed and manage. 

They can also be planted in a large container kept in a conservatory or greenhouse during the growing season. They should then be moved outdoors in winter, as grapevines need a period of cold to induce dormancy. Potted vines should be trained as standards, with one main stem and a rounded head, like a lollipop.

How to plant outdoors

Plant grapevines while dormant, between October and March, as long as the ground is not waterlogged or frozen. In areas with cold winters, March planting is preferable. The vine stems should be greater than pencil thickness, so they are not damaged by frost. Dig over the soil, breaking up any compaction and removing weeds. Enrich with home-made compost or well-rotted manure, plus a general purpose fertiliser at 100g (3oz) per square metre/yard. Tease out the roots and spread them evenly around the planting hole before backfilling with soil. 

For more details, see our step-by-step guide to planting climbers. 

When planting against a wall or fence, position the plant at least 12cm (9in) away from the base. If planting more than one, space them 1.2m (4ft) apart.

When planting in open ground, along a system of wires for support, space the plants 1.2–1.5m (4–5ft) apart, in rows 1.5–1.8m (5–6ft) apart.

After planting,  mulch with well-rotted organic matter or chipped bark to protect the lower buds from frost. Remove the mulch from around the stem in spring, to stop the stem from rotting.


 

How to plant in a container

Grapevines can be planted in large containers – choose a pot about 30–38cm (12–15in) wide and deep, and use soil-based compost such as John Innes No.3. Potted grapevines should be grown in a greenhouse or conservatory, then moved outdoors in winter to get sufficient cold for dormancy. They should be trained as standards, on a single upright stem with a rounded top, like a lollipop.
 

How to plant greenhouse grapevines

Grapevines are lovely plants to train along the inside of a greenhouse or conservatory, but they do require a lot of room. One vine is plenty for a small greenhouse – if planting more in a larger greenhouse, allow 1m (3¼ft) between each one.

Greenhouse grapevines grow best when the roots are planted outside and the vine is trained into the greenhouse through a gap near ground level. However, where this is not possible, the vine can be planted directly into the greenhouse border, but more watering will be required.

Double dig the ground, then incorporate a light dressing of well-rotted manure or garden compost, plus John Innes base fertiliser at 90g (3oz) per square metre/yard. If the soil is waterlogged, dig a hole 75–90cm (30in–3ft) deep and create a 15cm (6in) drainage layer of brick rubble, gravel or similar in the base.

When planting inside, plant the grapevine at the opposite end to the door, so the stems can be trained along the side of the greenhouse, parallel to the ridge of the roof and running towards the door.

The best time to plant is in November or December, as the vine can be pruned back without bleeding. Vines should be planted at the same depth they were in the pot. Gently tease out the roots, so they are well spread out in the planting hole.

For more planting tips, see our step-by-step guide to planting climbers. 

Grapes ripen from late summer to late autumn, depending on the variety and weather conditions. 

Dessert grapes are ready for picking when they feel soft and taste sugary. The skin of white grapes often changes from deep green to translucent yellow and becomes much thinner. But the best way to tell when grapes are ripe is by tasting them – pick them only when they’re at their sweetest.

Cut the whole bunch 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’re better pulped and made into wine. 

Recommended Varieties

Grapevines are prone to fungal diseases including powdery mildew (especially in hot, dry weather or in crowded sites with poor air circulation), grey mould (Botrytis) and downy mildew.

Birds and wasps can severely damage crops. Other potential pests include brown scale, woolly vine or currant scale and the fruit fly spotted wing drosophila (SWD).

Vines are also susceptible to nutrient deficiencies, particularly magnesium deficiency, and the physiological disorder shanking.

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.

Remedy

They thrive in hot, dry conditions, so mist plants regularly. Use biological control in the greenhouse.

Mealybug

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.

Remedy

Use biological controls and encourage ladybirds.

Grey mould

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.

Remedy

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.

Powdery Mildew

Appears as a white powdery deposit over the leaf surface and leaves become stunted and shrivel.

Remedy

Keep the soil moist and grow in cooler locations.

Buy now

The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.

Toplist

Latest post

TAGs