Grapes

Grapes need full sunlight and high temperatures to ripen.

If grown outdoors plant against a south facing wall or fence.

Choose deep, well-drained soils.

Avoid low ground since these will be cooler throughout the growing season which will delay the ripening of the fruit.

Outdoor Culture:

Week 7-13: Outdoor grape vines can be planted at anytime during February and March, (if not already done in October) providing weather and ground conditions allow.

Week 9: Take eye-cuttings.

When rooted, pot the cuttings in 125mm (5") pots of potting compost (equivalent to John Innes No. 2)

For pot culture, pot on as necessary and insert canes for support.

If to be grown on in the in the greenhouse border set the young plants in their permanent positions in June.

Alternatively, take 200-300mm (8"-12") long hardwood cuttings in October or November, insert the cuttings in their growing positions outdoors.

Week 10: Mulch established vines with well-rotted compost or manure.

Week 36: Prepare the planting site in a fertile, well-drained, sheltered sunny location that faces between south-east and south-west.

Dig in bonemeal at 60gms/sq metre (3oz/sq yd)

Vines grown in the open will require some form of support, the following arrangement should be quite adequate;

Drive or concrete in 75x75mm (3"x3") x 2m (6ft) long treated softwood posts at 4m (12ft) centres.

The number will be subject to the amount of plants to be grown.

Fit a sloping strut to each of the end posts to form straining posts.

Attach a single 2mm diam wire approx. 400-500mm (15"-18") from ground level then attach subsequent lines at 300mm (12") centres above this.

The wires should be fitted to eyebolts drilled through the posts.

Use 150mm (6")[minimum 100mm(4")] long eyebolts to ensure that when tightened they will tension the wires thoroughly.

Alternatively, a framework can be rigged against a building using eye bolts screwed into the masonry to take the wire supports.

Tensioning can be done with radiseurs purchased from a local fencing company.

The spacing should be similar to that described above.

An other alternative is to make a feature out of the supports and form a Pergola to support the vines.

The rods can be trained up the vertical posts and the laterals trained along the cross members, thus forming a shaded seated area.

Week 40: Plant outdoor vines by setting the plants at intervals of 1200mm (48") allowing 900mm (36") between the rows.

Single specimens are best grown against a wall.

Plant the vine so that the top of the compost or soil mark on stem is at ground level. (Allow a bit for mulching)

Insert a stake and secure it to the wires prior to filling the planting hole.

Prune back the main rod (central shoot) to within 600mm (2ft) off the ground, then tie to the stake.

Finally cut back remaining side shoots to leave one bud.

When the shoots begin to break, rub out all lower shoots and leave the top three or four to train along the wires.

Depending on how the vine is to be trained remove the weaker of these later to leave the fruiting rods that will be tied into a Tee or Fan shape.

Indoor Culture:

Week 1>: Prune indoor vines if not done earlier (see week 47)

Week 4: Untie the rods and let their tops arch over to encourage even breaking of shoots along their length .

Week 5: Take eye-cuttings.

When rooted, pot the cuttings in 125mm (5") pots of potting compost (equivalent to John Innes No. 2)

For pot culture, pot on as necessary and insert canes for support.

If to be grown on in the in the greenhouse border set the young plants in their permanent positions in June.

Week 6: For established plants, close the greenhouse down when growth restarts and tie the rods into place.

Most grapes need a long growing season and do best at a temperature of 13°C (55°F).

Spray the rods before mid-day with clean water to encourage growth.

Re-pot pot grown plants into fresh compost.

Week 8: In unheated houses, ventilate freely on warm days to delay growth while there is still a risk of frost damage to the young shoots.

When the young shoots are about 25mm (1") long, reduce them to two per spur, and when these are 75-100mm (3"-4") long, remove the weaker of the two.

Maintain a humid atmosphere, especially on sunny days, until flowering begins; thereafter ventilate the house freely.

Pollinate the flowers by hand or with a soft brush.

Week 16: When grapes come into flower, keep the greenhouse fairly dry to encourage good pollination.

Maintain a minimum temperature of 18°C (64°F).

Week 18: Stop fruiting laterals (side-shoots) by pinching out the tips, two or three leaves after the first bud cluster.

Non-flowering laterals should be stopped after the seventh or eighth leaf.

Week 24 - 28: When fruit reaches 5-6mm (¼) diameter, use a pointed stick and narrow-bladed scissors to remove up to two-thirds of fruit, avoid undue handling of the clusters.

Thin the fruit bunches to one per 300mm (12") of lateral stem, allowing a maximum of three on strong mature vines.

Pinch out the fruit bearing shoots at the second or third leaf after the cluster.

Subsequent side-shoot growth should be pinched back to the first leaf.

Tie non-fruiting shoots to support wires to keep them tidy, and shade fruit from hot sun.

Feed vines with balanced liquid fertiliser every ten days until the fruits have ripened.

Give ripening grapes under glass plenty of light and ventilation, but try to avoid draughty conditions.

Black varieties are beginning to ripen when they show a tinge of colour, whereas white grapes tend to look paler and slightly translucent.

Grapes can take six weeks to ripen.

As a general rule it is best to leave them a little longer to ensure sweetness and flavour.

When the fruits cease swelling temporarily during seed maturation (roughly when they are half grown) fluctuations in temperature and humidity during this time should be avoided.

After harvesting, reduce watering and give maximum ventilation.

Remove all sub laterals to help ripen the laterals.

Week 26: Plant indoor vines at 900-1200mm (36"-48") centres.

Initially grow the rods up canes until they reach a suitable height to be trained along wires suspended by means of eye bolts fixed to the roof of the greenhouse.

Water the young plants liberally to encourage them to make as much growth as possible during the first season, but allow only one stem (cordon or rod) to develop.

If only one plant is being grown, train two or three rods from it.

Week 39: Give ripening grapes plenty of light and ventilation.

Week 47: Prune indoor vines between now and the New Year.

If rod (stem) growth has been vigorous, prune back the current season's growth on main shoots by half to two thirds and reduce laterals (side-shoots) to about 25mm (1”) leaving a dormant bud to provide fruiting spurs for next year.

Dispose of the prunings, but retain lengths of sturdy shoots if you wish to propagate new plants by cuttings in late winter.

Remove any loose bark to deny pests potential winter quarters, and carefully paint rods with a winter tar oil wash, as a further pest preventative.

Week 50: Rest the vines in winter by giving full ventilation and allowing some frost into the house.

Apply a tar oil winter wash to the rods (if not done previously) while they are dormant and renew the top 25-50mm (1"-2") of border soil.





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