Aug 152009
 

Grapes

Edible grapes (Vitis vinifera) are vigorous deciduous woody vines native to Europe, northern Africa, and western Asia. They climb by means of tendrils, which wrap around objects to support the weight of the vine. Grapes are well suited to hot, dry conditions and full sun. Cultivated grapes have hermaphrodite flowers (both male and female) and are therefore self-fertile, they do not need a second plant as a pollinator. The flowers are pollinated by wind, insects and are also self-pollinated, developing into dense bunches of berries which we refer to as grapes.

Cultivated edible grape varieties are classified as either table (eating) grapes, which are sweet and have a pleasant flavour, or wine grapes which are too tart to eat due to their high acidity. A few, most notably the Muscats, cross over and can be used as both. Grapes can vary in colour from almost black through to green, red, and amber, and they may be seedless or contain seed. They can be use in a variety of ways, eaten raw, dried, used for making grape juice, wine, jams and jellies, and grape seed oil. Excellent on a cheese board, fun halved and frozen as an ice replacer in drinks.

Depending on the variety, the harvest period for grapes can range from mid-January for the very earliest of varieties all the way through to mid-May for the latest season grapes.

Being fast growing climbers, grape vines make great screening plants. They do need some kind of support to climb onto, though the support can be as simple as a trellis which consists of two posts with some wires strung across them. Grapes can be grown across the north or west sides of a house to provide summer shade and then allow the winter sun through after leaf fall in autumn. They’re also an outstanding climber to grow over a pergola to create a nice cool shaded spot to sit under in the peak of summer.

Growing grapes is relatively easy, they require a warm, full-sun position, with deep, moderately fertile soil. Grapes can tolerate a wide range of soil types from sandy soils to clay soils and will grow in soils of high or low fertility. They prefer soil of a neutral pH (around pH 7.0), though they can tolerate soil pH in the range of 4.5 – 8.5, which is acidic to alkaline, though grape vines grown in soils above pH 7.3 (alkaline) are prone to iron chlorosis as the alkalinity reduces the availability of the micronutrient iron.

There is some maintenance involved in growing grapes, they do require annual winter pruning and spraying with copper or lime sulphur fungicide, but beyond that once-a-year task, they’re quite easy to grow and look after. Grapes are deep rooted (but the roots are not invasive) which makes them drought tolerant once established, though it’s important to keep them moist during summer to produce the fullest fruit.

Grapes fruit on new seasons growth which rises from buds on the previous year’s canes (year-old wood), but they spend the first year putting their energy into sending their roots deep into the ground and putting on vertical growth. Production starts in the second year, and decent harvests are produced by the third year. Most varieties will take around 4-5 years to reach full production, and the longer the length the vine grows, the more fruit it produces.

If you’re looking to buy a grapevine, the best time to purchase one is during the winter bare-root season when there is the greatest range of grape varieties available.

Grape Season

The harvest season for grapes runs from November (very early season), peaks in February (mid season) and ends in May (very late season).

Planting your grape

When: The best time to plant your grapevine is anytime from the winter bare-root season through to springtime, as this gives the plant some growing time to spread its roots out establish itself before it faces the summer heat. The next best time would be in the milder autumn weather once the extreme heat has passed.

Where: Grapevines prefer a location with full sun, good air circulation, and deep well-drained soil for healthy growth and good fruit production.

Shallow soils, and soils which do not drain well should be amended to increase drainage otherwise the roots will stay too damp, which will lead to fungal diseases.
If planting more than one grape vine, make sure that they are spaced at least one metre apart or more.

Since grapevines are climbers, they need a structure to climb on. Make sure that you have a support in place for the grapevine to grow onto before planting it in the ground.

How: It is important to properly prepare the soil before planting, this is general good gardening practice which will prevent problems later on. The goal of soil preparation is to break up and loosen any compacted soils, increase moisture retention in sandy soils, and replenish soil nutrients to encourage plant growth and vigour.

• To prepare the soil for planting the grapevine, loosen the soil and mix in compost and cow manure, adding a maximum of 1/3 mixture of compost and cow manure to 2/3 soil.

• Dig a hole at least twice the width of the root ball near the base of the support structure and plant the vine. Backfill over the roots, firm down and water in well.

It’s a good practise to water in any newly planted plants with seaweed extract, as it contains plant growth stimulants which promote root growth, assisting the plant to establish itself quicker.

Feeding is important for plant growth, so if you didn’t apply any cow manure during soil preparation, you can sprinkle a handful of general purpose fertilizer at a distance of 30cm (1 foot) from the base of the vine a few weeks after planting.

Pruning and training your grapevine

Grapes are produced on the current season’s growth, and are pruned heavily each winter when dormant to produce the next season’s fruiting wood. There are two systems of pruning grapevines, cane pruning and spur pruning, which you use depends on the variety of grape.

Why two systems? The more fertile grape varieties will fruit on new growth growing closer to the base of the year-old cane, and these are usually spur pruned. The less fertile grape varieties will only produce on new growth originating from buds further down the year-old cane, and must therefore be cane pruned, which is a bit more fiddly technique. It’s important to note that some grape varieties can be pruned using either technique. Also, spur-pruned grape varieties can be came pruned for slightly greater yields.

For spur pruned grape varieties (see below), select two canes and train horizontally over wires or another horizontal support. This will form permanent framework canes. Once these canes are trained horizontally, they should start to produce canes from the buds along the length of this cane. These will form the spurs.

Cane-pruned grape varieties

These produce fruit on the current season’s growth on one year wood towards the end of the cane. Cane-pruned grape varieties include Sultana, Carina Currant, Crimson Seedless, Menindee Seedless, Muscat Gordo, Red Globe, Ruby Seedless, and Thompson Seedless.

Establishing a framework for cane-pruned grapes

After a grapevine been growing for a year to establish itself and gain some height, it needs to be pruned to the required shape to develop a framework – a trunk and branches suitable for cane pruning.

The first step to developing the framework is to allow one cane to grow up the support to the desired height and prune it back above bud. Branches will then form from the bud below the pruning cut and the buds below it.

For cane-pruned varieties (see below), select four canes as the current year’s fruiting canes.

Yearly pruning of cane-pruned grapes

In cane-pruning, four canes are selected to produce fruit, and these are renewed every year.

To cane prune a grape vine

1. Prune out the canes that produced the previous year’s crop. These older canes can be identified by the bark colour, which tends to be greyish in colour and rougher in texture, as compared to the newer smooth reddish-bronze canes (which grow from older fruiting canes).

2. Select two new healthy canes on either side of the trunk as the new fruiting canes and tie them to the trellis support wires.

3. Select a new cane on either side of the trunk as a renewal spur and prune them back to 1 or 2 buds. The renewal spurs will produce canes which may also be selected as next year’s canes.

4. Remove all other canes from the vine.

5. Shorten the four new canes to the desired number of buds, this will depend on the grape variety. Most varieties are pruned back to 8-16 buds from the base (not including the bud at the base).

Spur-pruned grape varieties

These produce fruit on the current year’s growth from permanent spurs. Spur pruned grape varieties include Autumn Royal, Black Muscat, Blush Seedless, Cardinal, Dawn Seedless, Early Muscat, Flame Seedless, Italia, Marroo Seedless, Muscat Hamburg, Purple Cornichon and Ribier.

Establishing a framework for spur-pruned grapes

After a grapevine been growing for a year to establish itself and gain some height, it needs to be pruned to the required shape to develop a framework – a trunk and branches suitable for cane pruning.
The first step to developing the framework is to allow one cane to grow up the support to the desired height and prune it back above bud. Branches will then form from the bud below the pruning cut and the buds below it.
For spur-pruned varieties, select two canes as permanent lateral arms, one on either side of the trunk, and tie them back to the horizontal wires of a trellis or frame of a pergola. Once these canes are trained horizontally, they should start to produce canes from the buds along the length of this cane. These will form the spurs.

Yearly pruning of spur-pruned grapes

In spur pruning, new canes are selected to form spurs and pruned back to two buds. These two buds will then produce two fruiting canes. These spurs are renewed every year.

To spur prune a grape vine

1. Prune out the canes that produced the previous year’s crop. These older canes can be identified by the bark colour, which tends to be greyish in colour and rougher in texture, as compared to the newer smooth reddish-bronze canes (which grow from older fruiting canes).

2. Select new canes to be cut back to form the new spurs. Prune back these canes back to two buds from the base (not including the bud at the base). Select healthy growth that is spaced evenly along the length of the framework cane, and usually buds are selected that face upwards. Keep the spacing at approximately 15-20cm apart.

3. Prune off all other growth from the framework canes.
Each year, all new growth from the spurs needs to be shortened to the second bud.

Watering and fertilising

Grapevines are drought tolerant but need regular watering during the growing and fruiting season, for optimum production. Watering is usually necessary from early November to late.
To conserve soil moisture and reduce water needs, ensure that the soil around the grapevine is mulched during the summer months.

Fertilize with a slow release balanced fertilizer in spring, if you use manure (which mainly contains nitrogen and phosphorus) it is best to supplement it with potassium (potash) or seaweed extract (which is rich in potassium) during flowering. Grapes don’t need much fertiliser, so don’t overdo it, and don’t use fertilizers that are too high in nitrogen.

Pests and diseases

Grapevines can be prone to fungal problems in humid areas, so avoid wetting the foliage when watering to minimise the risk of disease.

Fungal diseases are best prevented by using a copper-based fungicide or lime-sulphur when the grapevine is dormant, spray according to the product’s directions.

When in leaf, grapevines in high humidity can be affected by powdery mildew, a greyish-white powder covering the leaf surface. This is a fungal disease which can be treated by spraying with potassium bicarbonate (which goes under the product name of Eco-fungicide), or by using a spray of bicarbonate of soda (which is not as effective) – one teaspoon of bicarbonate of soda into one litre of water and add one drop of detergent and one drop of vegetable oil to make it stick to the leaves.

Some gardeners believe that spraying the vine with a bit of seaweed extract (Seasol, Multicrop etc, diluted to foliar feed concentration) can help prevent fungal problems.

If you want to go all the way with fungicide treatment and do what organic farmers do, you can apply wettable sulphur fortnightly from mid-September to late December. Growers usually change over to from wettable sulphur to sulphur dust once the fruit has set. Do not apply sulphur on days when the temperature is to be 30°C or higher.

One pest which can affect grapes is the grape leaf blister mite, which causes raised blisters on a grape leaf which are often mistaken as a fungal disease. The damage is mainly cosmetic, the leaves may look unsightly, but fruit production is not affected. Spraying with lime sulphur at bud-swell should adequate control this pest.

Phylloxera

Now, a serious word of warning with regards to grapes. Due to a nasty little pest of both edible and ornamental grape vines – Phylloxera – movement of grape vines is seriously restricted in Victoria. Before you take your grape vine, vine cuttings, or ornamental grape vine for a ride in the car from one part of the state to another, make sure you are well aware of the Phylloxera exclusion zones that exist throughout Victoria. For more info, check www.dpi.vic.gov.au

Grape Varieties

Now, onto the fun part – picking a grape variety. Here at BAAG we carry a bunch of different grape varieties for most of the year, however please be aware that not ALL those listed below will be available at all times.

Autumn Royal: A hybrid seedless black grape with crisp sweet flesh. The fruits are large and oval shaped with blue black thin to medium skin and delicious firm and sweet translucent yellow-green flesh, with a pleasant and distinctive flavour. Late maturing and spur pruned.

Beauty Seedless: Large clusters of small (same size as sultana grape) seedless black grapes with a firm tender sweet flavoured flesh.

Black Hamburg: This variety is the same as the Great Vine at Hampton Court Palace which is now the oldest and most famous grape vine in existence. Also known as ‘Schiava Grossa’. The grapes ripen in large bunches of dark red / purple seeded fruits, the fruit is medium-large in size and has superb flavour. Hardy and consistently prolific with stunning autumnal foliage.

Black Muscat: Table or wine grape, also for drying to make raisins. Grapes are mid sized, round, dark reddish skin with bloom, compact bunches, strong rich muscat flavour. Vigorous and reliable vine. Spur or cane prune. Matures late summer.

Black Sultana: Red to black seedless table grape. A heavy cropper that bears medium sized, oval shaped fruit and ripens mid-season.

Blush Seedless: Bright red, oval and seedless, may be uneven in size. The skin is tender and crisp with meaty flesh. Bunches are large, compact and well filled in, uniformly long, conical and symmetrical.

Cabernet Sauvignon: A black grape that makes an excellent red wine of good colour, tannin and varietal character. Vigorous growing vine. Provides good summer shade when grown over a pergola. Best in cool regions. Mid season grape.

Cardinal: Popular table grape. Very sweet large round red grapes. An excellent table grape. Cane prune. Suitable to grow over a pergola. Very early season.

Carina Currant: Small, seedless, very sweet black grape that is suitable for fresh eating or drying. Larger than Zante Currant.

Chardonnay: Makes a high quality wine with distinctive character. Medium vigour vine, spur prune. Early season harvest.

Crimson Seedless: A bright red seedless grape. Crisp firm sweetly tart, almost spicy fruit. Great fresh or in fruit salads. Can also be used to make raisins.

Delight: A very good grape for coastal and mild winter (low chill) areas. Seedless. Large size. Greenish-yellow, resembling Thompson Seedless in color. Crisp, delicate Muscat flavour. Fine keeping quality. It produces heavily in big, loose clusters. Table and raisin use.

Diamond Muscat: An early season white seedless with a pleasant and mild muscat flavour – slightly more intense than that of Summer Muscat. Lovely dessert grape but also makes superb raisins. Raisins dried on the vine have a stronger muscat flavour than tray dried one.

Early Muscat: Medium sized very early maturing berries with a strong muscat flavour. A table grape that has also been used successfully as a wine grape.

Fantasy Seedless: A mid-season blue-black seedless table grape. The large berries are thin skinned, firm and have excellent flavour when fully mature. They are seedless, sweet, oval and form cone-shaped clusters. The flesh is pale green in colour and juicy with a mellow flavour.

Flame Seedless: These light red seedless grapes are crisp and juicy and ideal for snacking on or in salads. Round in shape, medium sized with firm flesh, they hold well on the vine. These are the crisp, red seedless grapes found in most supermarkets, but are even better when allowed to vine ripen.

Glenora: Looks simply fantastic on a cheese platter, and the flavour perfectly complements the sharper cheeses. Vigorous highly productive vine with excellent disease resistance producing large, blue black, seedless dessert grapes. These grapes are sweet, juicy and have a unique spicy underbite. A fine thin skin adds to the perfect package. Fruits early in the season.

Grenache: A wine variety. Thin skinned with tight bunches, the vine buds early and requires a long growing season in order to fully ripen. Grenache is often one of the last grapes to be harvested. The high sugar content makes sweet bunches of grapes (and high alcohol levels in wine). Pale red coloured fruit.

Himrod: The most successful table grape released from the Cornell University grape breeding program (1952). It produces large bunches of white seedless grapes with excellent, honey-like flavour and melting, juicy texture.

Italia: Very popular table grape. Large, golden coloured, seeded grapes. A good, white muscat flavour. Virus free, reliable and heavy cropping. Tolerates wet conditions. Can be grown over a pergola. Mid to late season maturity.

Marroo Seedless: A mid-season variety recently developed in Australia. Juicy berries with a mellow flavour and a crisp skin. A vigorous and productive vine.

Mataro (Mourvèdre): A black-skinned variety that has been grown in vineyards all around the western Mediterranean for centuries. Thought to have originated in Spain, it is now grown extensively throughout the Iberian Peninsula, southern France, California and South Australia.

Menindee Seedless: Light green to yellow oval-shaped grape with deliciously sweet, firm flesh and no seeds. Exceptional grape, very popular. Superb grape eaten fresh – but can also be used in hot dishes.

Muscadine Adonis: Large ripe fruits (20-25mm) are golden bronze in colour, sweet and juicy with a delicious and distinctive fruity flavour.

Muscadine Fry: Sun-sweetened bronzed beauties. This improved form of the Scuppernong originates from Georgia, USA and produces larger, sweeter, and heavier-bearing crops than others of its kind.

Muscat Gordo: Fabulous strong muscat flavour in a large fleshy white fruit. One of the earliest grapes used for wine making, now commonly used for drying or as a desert grape.

New York Muscat: Superb seedless (or partially seedless) Black Muscat Grape. Lovely intense muscat flavour with sweet blackcurrant tones. A large blue black grape. Can be used as a magnificent table grape or to make wine.

Ohanez: Golden green, medium to large in size, cylindrical and seeded. Thick and tough skinned, with firm juicy flesh with a neutral flavour. Late season.

Perlette: Pale green seedless crisp juicy fruit with a thin white skin – ideal table grape for cool climates. Requires less summer heat than other white varieties.

Pinot Noir: Black grapes on a vine of relatively low vigour – will not swamp your pergola! Makes an excellent red wine of varietal character. Suits cool regions. Early season.

Purple Cornichion: Large clusters of elongated to egg shaped berries, with thick purple skin and soft juicy flesh and seeds.

Red Globe: A table variety developed in the late 1980s with very large appealing seeded dark ruby red round berries. Crisp and crunchy with a delicious delicate sweet fruity flavour. Popular for eating and decorating. Ripens late.

Rhine Riesling: Wine grape. Green-yellow small grape of moderate vigour. Suits cool regions. Produces an excellent white wine with varietal character. Suitable to grow over a pergola. Spur prune. Mid-season.

Ribier: One of America’s bestselling grapes. A mid-season cropper with big bunches of large round sweet black berries, with a slight tart tang and a few seeds.

Ruby Seedless: This mid-season variety has large clusters of small to medium crisp red seedless fruit. Bold textured foliage makes it ideal to train over an arbour or pergola.

Sauvignon Blanc: Small white fruit maturing mid-season, flourishes in Australia’s cooler regions. Incredibly popular variety over the last 3 decades, seems to be taking over the wine world after so long being a little idiosyncratic variety from the Loire Valley.

Shiraz (also known as Syrah): Dark-skinned and delicious. Grown throughout the world to primarily produce intoxicating heady red wines. This grape is very versatile and also produces scrumptious juices and jellies and can be eaten right off the vine as a refreshing snack as well.

Suffolk Red: These grapes are seedless, have very tender skin and are delicious eaten fresh (tender skin makes them appear to almost melt in your mouth) or chilled as a dessert. Very juicy with a tangy, sweet and spicy flavour. Bunches are open and loose. Good autumn foliage colours as a bonus.

Sultana: Popular table grape. Long bunches of medium sized, oval, seedless, yellow green to copper skinned, sweetly flavoured grapes. Needs warm, dry conditions.  White table grape and for drying as sultanas. Also used as a ‘filler’ in wines. Suitable to grow over a pergola. Cane prune. Mid season.

Summer Muscat: A seedless raisin grape. It has the sweet, strong muscat flavour that is so popular. Wonderful table grape.

Thomson Seedless: A very popular, consistent heavy cropper with seedless berries, thin skin and firm very juicy pulp. Very sweet and good flavour. Not much more to say really – unbelievably popular grape.

Venus: Large with a blue-black colour. Its flavour is a wonderful sweet fruitiness with a suggestion of muscat. Excellent for table, wine, and juice. Very vigorous with good productivity.

Waltham Cross: Loose, conical bunches of large, oval grapes. Yellow – green to gold skin, crisp flesh with very good flavour and one seed. Vigorous vine. Mainly used as a table grape due to its good flavour. Also used for drying (raisins). Spur prune. Late summer to early autumn.

White Muscatel: Large yellow-green, seeded grapes with firm, very sweet flesh with strong muscat flavour. Great for drying (raisins), as a table grape and in white muscat wine. Not vigorous but bears heavily. Spur or cane prune. Mid to late season.

Zante Currant: Also known as Black Corinth. Small intensely sweet, intensely flavoured deep black grapes. Seedless with a tender skin. Beautiful fresh, or more conventionally, dried.

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