Grapes
Grapes are very long lived and vines can survive for a century or more. They tolerate all sorts of soils and climates and are drought-hardy due to their deep roots.
Grapes are such giving plants. They provide bunches of delicious fresh fruit that can be transformed into wine. If the vine is trained over a pergola, they also give cool shade right through summer and autumn.
If you’ve opted for an ornamental rather than fruiting variety you can also enjoy glorious autumn colour as its leaves colour brilliant red, burgundy and yellow before they drop. In return, all they ask for is a hard prune in winter.
Grapes are very long lived and vines can survive for a century or
more. They tolerate all sorts of soils and climates and are drought-hardy due to their deep roots. Although they get by with little care or attention, for a good harvest you need to put in some work to train, manage and care for your vine throughout the year.
Why grow a grape?
The first question to answer is to decide what you want to do with
the grapes you produce. If you want to harvest the crop for your own wine vintage or to have worthwhile amounts of table grapes, then it’s necessary to grow the vine or vines on a traditional trellis or fence. This is done so they are easy to maintain, to protect from birds, and to harvest.
Select the variety you plant with care as there are varieties for winemaking, others that are better for eating fresh (known as table
grapes), some that are dual purpose (both drinking and eating) and yet others that are suited to drying (for raisins or sultanas, for example).
Grapes can be seedless (that is, with no seeds or very few)
or seeded and the fruit can be red (known as black) or green in
colour. There is also a difference in ripening time, fruit size, disease resistance or susceptibility and, of course, flavour between the myriad varieties available.
If your interest in a grapevine lies more in enjoying the shade beneath the vine and adding a splash of autumn colour to the garden, simply select an ornamental vine and grow it over a pergola.
Growing needs
Winter chilling requirements are low compared to other deciduous
fruit plants — around 150 hours, which means they can be grown in many parts of tropical and subtropical regions as well as in traditional grape-growing regions that have a cool or Mediterranean climate. Although grapevines grow in most areas, grape quality and production are best in areas with cold winters and hot but dry summers.
Vines are widely available for purchase in winter and this is the
best time to plant a grapevine or a vineyard. A productive, well-trained and pruned vine can yield 40 bunches of grapes.
For fresh grapes over many months, select varieties that ripen
between midsummer and late autumn. Popular varieties include ‘Flame Seedless’ (early to mid-season) and ‘Thompson Seedless’, also called ‘Sultana’ (late season). This variety is also grown for drying as raisins.
For wine production, many vines of the same variety are needed to
provide the quantity needed to press. Those 40 bunches of grapes per vine may yield only four bottles of wine!
Troubleshooting
Many pests attack grapevines and their succulent fruit, from
caterpillars that feast on the newly opened leaves to birds that peck
at the ripening grapes. Large pests such as birds are managed in
an organic garden by using exclusion methods such as netting over
vines or bagging of fruit clusters.
Insect pests may require other physical or chemical intervention.
The caterpillars of grapevine hawkmoth and grapevine moth feast
on grape leaves and can skeletonise leaves and defoliate the vine.
They can be removed by hand or sprayed with an organic caterpillar control such as Dipel, or Bt (Bacillus thuringiensis).
Grapeleaf blister mite and grapeleaf rust mite are microscopic
insects that cause blistering damage on leaves. Although the vine may look tatty, fruit will not be affected. To control mites, remove
affected leaves and make a note to spray in late winter, after pruning, with lime sulphur.
Downy mildew is a fungal disease that attacks grape leaves,
causing brown, yellow or red patches on the top of the leaf with
patches of white downy growth on the underside. Remove affected
growth and use preventive control in winter by applying a Bordeaux mix, a traditional treatment made from a mixture of copper sulphate and slaked lime.
In warm or humid areas, the heritage variety ‘Isabella’, a table
grape, is grown for its disease resistance. Grapes that are well
managed, watered in spring but left drier through summer, will also be less susceptible to disease.
Grapes that don’t receive full sun as they ripen may be slow to
ripen or may ripen erratically.
Pruning & training
Pruning is the number-one task when it comes to managing a productive vine. While the base of the vine can be old, gnarled and thick, the fruiting canes are constantly renewed to maximise fruit production. Pruning in winter removes old wood and encourages new, productive wood.
In the early years after planting, each vine is trained to its desired height and encouraged to form a framework of horizontal growth. The general rule once the framework is established is that each winter the previous year’s growth, some 90 per cent of the plant, is cut back to the horizontal framework.
Some varieties have more specifi c pruning needs, so it’s important to check on the correct pruning method for the variety you’re growing.
Harvest, storage & preserving
Grapes ripen in late summer and autumn, the timing depending on
the variety and the growing conditions. Grapes are harvested when
the fruit is at its maximum sweetness. They can be eaten fresh, used to make to wine, vinegar or verjuice, or dried.
While you’re waiting for your first grape harvest, the new spring leaves can be used to wrap foods. Dolmades (stuffed grape leaves) are a traditional dish made from grape leaves (see our previous issue). The leaves can be blanched and frozen or packed into brine for storage so they can be used later in the season.
Warm Grape & Walnut Salad
Serves: 2
1 tbsp sesame seed oil
1 celery stick, sliced on an angle
1 carrot, peeled into ribbons
½ cucumber, peeled into ribbons
½ fennel bulb, thinly sliced
2 spring onions, sliced on an angle
10 grapes, halved
50g walnuts
50mL red-wine vinegar
- Heat sesame oil in a wok over medium heat.
- Add all ingredients except red-wine vinegar and toss through the heated oil for 2 mins.
- Add vinegar, toss and infuse for 30–40 secs.
- Serve in an iceberg lettuce boat.
