Table Grapes

By Anna-Marie Barnes
This article was originally published on lifestyleblock.co.nz.

In a land where wine grape-producing vineyards are a dime a dozen, if you mention table grapes to the average New Zealander, their thoughts will likely settle on the large bunches of majestic-looking but rather tasteless imported fruit to be found in supermarket chillers year-round. But if we cast our memories back, many of us can probably remember a sprawling vine tucked in a corner of our grandparents’ section or running along the fence line of a childhood home. Nothing screams autumn like the musky-sweet scent of homegrown grapes, hiding in amongst their leafy surrounds and just waiting for the keen eyes of a backyard treasure-hunter.

I’ll be up-front and admit I am a huge fan of older, ‘heritage’ fruit varieties, so if you are looking for thin- skinned, largely seedless delights, avert your eyes…on the plus side, grape skins and seeds are packed with antioxidants, so no harm in chewing them up. This article is a walk through some heirloom delights, big on Wavour, character and hardiness. I believe they deserve a place in your garden and might just help Xll your fruit bowl before the cooler months hit.

Table grapes: a short family history

The table and wine grape species we are familiar with are from the Wowering plant family Vitaceae, which consists of 14 genera of predominantly vining plants. The genus Vitis contains almost eighty species, mainly originating from the Northern hemisphere. The two Vitis species most commonly encountered are Vitis vinifera, the European wine grape, native to the Mediterranean, Central Europe and southwestern Asia and most commonly utilised for wine production, and Vitis labrusca, the fox-grape, native to eastern North America, the provenance of many table and early-era wine grape cultivars.

1. labrusca has the advantage of being more cold-tolerant and disease resistant than its European cousin, and as a result, many hybrid species have been bred, with varying degrees of success in regards to end use. V. labrusca vines are robust (it is not uncommon for vines to become invasive in their native range), and distinguished from V. vinifera in that they have tendrils present at every node, and large, thick leaves with downy white or brown undersides. They are also tolerant of, or at least have a degree of resistance to the root-feeding aphid pest Phylloxera, to which V. vinifera is famously susceptible. The three table grape varieties I will discuss in detail are all cultivars of V. labrusca, but there are several dual-purpose V. vinifera cultivars that are also popular table varieties, such as the Muscats.

You may be wondering where the name ‘fox-grape’ comes from. If you’ve eaten fragrant home-grown table grapes, especially the larger black varieties from old vines, or consumed black grape juice or that fabled American stalwart, grape jelly, you’ll be familiar with the earthy, sweet, musky, and well – unmistakeably ‘grapey’ Wavour and aroma. Back in the day, early settlers from Europe who were establishing themselves in the New World coined the term ‘foxy’ to encompass these strong aromas found in the North American grape species (and the resultant wines) to distinguish them from the distinct (and probably more delicate) characteristics found in the European varietals they were accustomed to. We now know that the aroma compound responsible for ‘foxiness’ is methyl anthranilate, which is now commonly used as a food and beverage Wavour, in perfumery, and also (I think rather amusingly) as a bird repellent to protect seed, grain and fruit crops and pastures such as golf courses. Ironic, seeing as birds are such a fan of grapes in general. I often wondered how a local producer of V. labrusca grapes got away without netting the crop, there might be the answer!

Suitable climates and growing conditions

With our commercial viticulture industry spanning regions across both islands, the hardy table grape will grow with at least some success in most areas. I lived on the South Island’s West Coast for several years, and we had some considerable harvests from vines there in good years, so much so that one year my Dad took to producing grape juice, albeit on a household scale. In the wetter regions, you just need to pay particular attention to site selection and canopy management to ensure a reasonable yield. The ideal climatic conditions for grape growing are cool winters, hot sunny summers and dry autumn conditions during the harvest period, which can be from February to April, depending on the cultivar and growing region. The main climatic issues likely to be faced are frost damage to young spring foliage in cooler regions and pre-harvest defects such as fruit rots and berry splitting near harvest in areas with higher rainfall.

Site selection and planting

Grapevines, like most deciduous fruiting plants, are established in the dormant winter season. They can be grown from hardwood cuttings, which is handy if you want to propagate from a particular vine, or from container-grown or bare-rooted plants purchased from a nursery. Grafting on to an existing vine is also an option if you wish to switch cultivars, with the added advantage of the beneXts of an established rootstock. V. labrusca grapes usually perform well on their own roots, having a degree of natural tolerance to Phylloxera (more details below) but if you choose a Muscat variety (V. vinifera), it is best to purchase a vine grafted on to a resistant rootstock.

Grapes are tolerant of most soil types, but free-draining soil with some water holding capacity is ideal. In very heavy soils you may encounter issues such as root rots, so these are best avoided. Choose a sunny, sheltered aspect – north-facing is ideal, and planting on a slope can assist in frost-prone areas. Some form of support structure is necessary, and if an existing framework is available, utilise it! Pergolas, trellises and fence lines are perfect, and may need little modiXcation to support your vine or vines. It is best if you can have a support structure in place prior to planting, before the new growth takes off in the spring. If you are planting more than one vine, allow about two metres between vines on fence lines or trellises, dropping this to about 1.2 metres if you aim to cover a large space like a pergola.

Dig your planting hole wide enough to spread out the roots without bending or breaking them, and as deep so the plants can grow at the same depth they were at in the pot or nursery bed. It’s important not to plant grafted vines too deeply; if the graft zone is buried, the scion region may start to root. Fertiliser requirements are minimal, and if too much is applied, the vine is likely to produce an excess of vegetative material and be light on fruit production. Side dressing with compost a couple of times a year may be all that is necessary in most home garden situations.

Young vines will struggle with weed competition, so keep the area under the vines free of weeds by cultivating gently and not too deeply as you don’t want to disturb the roots. Grapes are highly susceptible to spray damage from herbicides, via both direct application and spray drift, so be extremely judicious in your use of these around vines. Apply sugcient irrigation during the establishment phase to ensure the young vines do not become water stressed, and continue throughout the vigorous spring growth phase and Wowering/fruit set in early summer. Drip tape at the base of the vine is ideal; avoid overhead systems as excess moisture in the canopy encourages foliar diseases and fruit rots during ripening. Water requirements decrease during the ripening season, however if you are in an area with long dry summers but prone to late rainfall, light irrigation in the ripening period can help prevent berry splitting which may occur after a rain event on unirrigated vines.

Culture and care

The vineyard calendar year – approximate timing of events:

Grapevines are easy-care garden additions in that they are wind-pollinated and self-fertile, bearing Wowers with both male and female parts present. You can expect vines to reach mature cropping capacity at around Xve years of age, and yields in the region of 15 kg/vine are possible. A grapevine can be a long-term investment, with lifespans of over 50 years not uncommon. The dormant season for vines ends around September with the arrival of bud burst, followed by shoot development in October. In November, you may want to thin and space the growing shoots to allow good canopy airWow, light penetration and improve fruit quality. Vines will usually produce more than one shoot per bud, so thin these down to the single strongest shoot. Fruit is borne on the current seasons’ growth, with inWorescences appearing a reasonable way in to the growing season, around November or December. Once the fruit has set, to ensure fruit quality and avoid over-cropping and stressing the vine, you can thin the bunches down to one or two per shoot. Fruit development continues throughout January and February, and you will start to see the berries swell and change colour as the ripening period commences. You can judiciously remove some leaves in the fruit zone to expose the bunches to light and increase airWow, but don’t remove too many as you will risk sunburn and leaves are still required to feed the fruit. This is also a good time to get out your bird nets, as the fruit becomes noticeably more attractive to our feathered friends during this time. Once the fruit has suffered bird damage, there may be the additional hazard of wasp infestation as opportunists move in to take advantage of the ready source of sugars.

Pruning

After planting a new vine, the number one goal is to establish a good root system and a sturdy trunk. You can do this by either selecting the strongest shoot present and training it using a string or stake so it eventually reaches your wire or other support system, or leaving the vine to develop into a bush for the Xrst year and develop the trunk in the second year – this option also allows for the selection of multiple trunks if desired. Once you have selected this cane and it reaches the desired height, in the dormant season of that year, trim it by cutting through a bud approximately 10 cm above the wire or support trellis height, and secure it to the support. It is interesting to note that pruning cuts for grapevines are made straight across at a right angle to the bud, as opposed to on an angle for most other pruning cuts, and the cuts should not be made too close to the nodes, as dieback usually occurs.

The next step is to select a pruning method, for grapes there are two systems to choose from: cane or spur. If you are unable to Xnd out which pruning method best suits your chosen cultivar, start with cane pruning, and if it does not result in adequate fruit production, you can shift to spur pruning. Spur pruning often suits frameworks such as pergolas and fence lines where a more permanent vine structure is favourable. Both of these methods produce shoots that can be trained into a downward hanging curtain (popular for table grape production in the USA) or upright shoots – the latter may require one or two moveable foliage wires to hold everything in place as the shoots grow longer.

Cane pruning involves selecting two shoots growing from the main trunk you developed in the Xrst year to form a T-shaped vine framework – choose an opposing pair about 5-15 cm below your support wire or structure, and secure them horizontally to the wire with ties – these become your fruiting canes. Prune off the rest of the shoots growing below the fruiting canes from the trunk, and remove any fruit and suckers so growth is channelled only into the shoots you are keeping. When the vine goes dormant again, shorten your two canes back to no more than 10 buds per cane. It is these buds that will produce fruit in the following year. After the vine produces fruit on the new shoots in the third year and goes dormant once again, comes the scary part – to ensure continued fruit production and a good vine structure, you need to prune off 80 to 90% of the current season’s wood. Choose two canes (one per side) close in to the trunk to form the new fruiting canes, laying them down and trimming as for the previous year. Choose a further two canes near these new cordons and trim them to one or two buds – these are your renewal spurs for the following year. This process is now repeated in perpetuity each annual dormant season.

Spur pruning differs from the above process in that after the third growing season, instead of choosing two new fruiting canes to lay down and two replacement spurs, the old horizontal canes are retained and become cordons – a permanent part of the vine structure. Each of that year’s fruiting canes are then cut back to 2-3 bud spurs, spaced about 10 cm apart along the cordon, aiming for about 30 buds per vine. In subsequent years, the process is repeated, again selecting 2-3 bud spurs comprising one year old wood sections close to the cordons, spacing them appropriately as before and aiming this time for no more than 60 buds per plant, depending on the variety and age of the plant.

It is good hygiene practise to dispose of prunings by burning or mulching and composting to prevent the spread of disease.

Pests, diseases and what to do about them

As mentioned, V. labrusca table grapes are hardy beasts and are less susceptible to ailments than their European cousins. Here are a few of the most common pest and disease issues likely to be encountered by grapes in general.

Phylloxera is a grapevine root-feeding aphid, native to North America, which was transported to Europe on the roots and soil of exported vines in the 1850s, devastating the wine industry there. North American grape species have varying degrees of natural resistance to Phylloxera, having co-evolved with the pest, and as such a number are used as rootstocks for the vulnerable European species. The use of grafted plants on resistant rootstocks is the sole management strategy for Phylloxera; the pest is now present in most wine- growing regions worldwide and due to its soil-dwelling nature, is impossible to eradicate once established.

Mealybugs are soft-bodied sap-sucking insects from the order Hemiptera, which have detrimental effects on grapevines, namely decreased vine vigour due to feeding activity and acting as vectors of grape leafroll viruses. They can also cause phytosanitary issues in other export fruit crops. Though unlikely to impact home garden production, environmentally-friendly control strategies for outbreaks include softer-option horticultural oil sprays, and the biological control agent Cryptolaemus montrouzieri, a ‘wolf in sheep’s clothing’ predatory ladybird species which is commercially available.

Fungal diseases affecting grapevines include powdery mildew (Uncinula necator), downy mildew (Plasmopara viticola) and botrytis bunch rot (Botrytis cinerea). Cultural controls that may help in the home garden setting include maintaining an open canopy with adequate airWow throughout the season, avoiding overhead watering and maintaining good hygiene after pruning by removing spent canes from the area. Lime sulphur spray applied in the dormant season is one option for the control of powdery mildew.

Birds are the number one enemy standing between you and your grape crop. Net fruit at veraison, as soon (or just before) the berries start to turn colour. Wasps will likely follow the birds, feasting on the sticky juice of punctured berries. Consider installing a wasp trap or two in the vicinity of your vines if numbers get out of control.

Varieties: My top picks

Niagara (sometimes known here as White Albany)
Berry colour: Green-gold
Approximate ripening period: Late February to mid-March
Niagara is an outstanding fresh eating grape with a sweet, aromatic Wavour that belies its green colour – you will often smell them before you see them. Niagara originates from Niagara County, New York State, where it was bred by crossing Concord, the famous American juice-and-jelly black grape with Cassady, a white variety. It became a commercial variety in 1882 and is still used for the production of white grape juice in the USA. As it starts ripening in February in some areas of New Zealand, it is a good option to plant alongside one or two of the later-ripening varieties to provide fruit right across the season.

Iona
Berry colour: Pink
Approximate ripening period: March-April
This diminutive dusky-pink beauty is the grape of my childhood, although I only came to know it by name as an adult. Wherever we moved as a family, there was always a vine of this variety in the backyard and I feel it deserves a higher proXle. In the New Zealand climate it is deemed a hardy variety, touted to be suitable for coastal conditions and with a degree of resistance to the fungal diseases which plague grapes, therefore suitable for areas with higher humidity. The mid-season fruit is small but sweet and aromatic. A little research reveals that Iona has a somewhat chequered history, rising to fame towards the end of the American Civil War. An open-pollinated seedling of the variety Diana (which is itself a seedling of Catawba, “the Xrst great American grape”), it was brought into the public eye in 1863 by a plant-breeding dentist by the name of C.W. Grant. Much puffery and promotion ensued (with fans and detractors in equal measure) and although it showed promise as a wine grape, as well as for table and juice purposes, it also was deemed to have a number of defects and as such, has all but disappeared from commercial production in the USA. It remains a popular home-garden cultivar in New Zealand, seeming to do well in our maritime climate, and one commercial fruit winemaker in the Auckland region produces a single varietal Iona wine.

Albany Surprise (other common synonyms include Isabella and Fragola) Berry colour: Black
Approximate ripening period: mid-March to late April
A New Zealand selection of the American variety Isabella, Albany Surprise was once our mainstay national backyard grape. Its propagation is attributed to Mr George Pannill of Albany, Auckland in
c. 1900, and the rest is history. The original Isabella is thought to perhaps be not a true V. labrusca but a labrusca x vinifera hybrid as it is said to have some susceptibility to fungal disease. One school of thought regarding this cultivar’s origin is that it was discovered in 1816 by Mrs Isabella Gibbs of South Carolina, but there are conWicting reports of it originating in other parts of the country as well. Whatever its provenance, this heavy-cropping, Wavoursome variety deserves to be preserved in perpetuity. As well as a dessert fruit, it makes excellent juice, jam and even pie Xllings.

Bishop Pompallier
Berry colour: Black
Approximate ripening period: Early March

Although I’m not personally familiar with this cultivar, I think it deserves a mention as part of our national heritage. A large, sweet black grape, it is said to have arrived on our shores in 1838 with Bishop Jean Baptiste François Pompallier (the Xrst Catholic bishop of the South PaciXc) and was planted in the Hokianga. Given its origins, there is little doubt it was used to produce communion wine at the time, and it now enjoys modern-day status as a Wavoursome dessert variety.

What to do with your crop

Apart from the obvious suitability of grapes as a fresh fruit for eating out of hand, here are some additional uses for your harvest.

Try your hand at home made grape juice and bottle your excess for winter days – you can Xnd instructions on how to process this online.

If you have a crop that fails to ripen sugciently, or an unpalatable cultivar, make a batch of verjuice – a tart condiment that can be used in salad dressings and sauces to add a bit of bite.

Use black grapes to make a tasty fruit pie Xlling, jam or jelly.

Make your own wine vinegar.

Freeze surplus bunches as a cooling snack for hot summer days (if they last that long!).

Use the young leaves to make dolmades (Xlled vine leaves) in spring. Livestock, especially sheep and goats will appreciate any summer prunings.

Use the dormant canes (while still Wexible, straight after pruning) to make decorative wreaths. Grapes, even underripe fruit or wine grapes, make excellent sauces – see below.

Here is a recipe for grape ketchup adapted from a WW2-era pickling book (waste not, want not). I made a batch one year using some black wine grapes and friends dubbed the result “Grape HP” after the famous sauce. See what you think!

Grape ketchup

2.5 kg stemmed grapes 600 ml vinegar
Simmer these two ingredients together in a large pan for thirty minutes, then pass through a sieve or mouli. Return the pulp to the pan, and add:

500 g sugar
1 tablespoon plain salt
1 tsp ground cinnamon
1 tsp ground cloves
1 tsp ground allspice
1 tsp ground cayenne pepper

Simmer until fairly thick; about an hour. Heat clean glass bottles or jars in the oven at 125°C for 30 minutes and boil their lids in a saucepan of water on the stove top for 10 minutes. Fill the bottles with the hot sauce and screw down the lids. Store in a cool pantry – this should keep well for 2-3 years, improving with age. It goes well with cold meats and cheeseboards.

Anna-Marie Barnes is an active member of the New Zealand Tree Crops Association who endeavours to grow and preserve as much of her own fresh produce as possible. When the weather’s no good for gardening, she can usually be found inside working on a batch of homemade cheese or soap.

Find out more about the New Zealand Tree Crops Association here: https://treecrops.org.nz

Niagara grapes
Image: Andrew Leahey, CC BY-SA 2.0, via Wikimedia Commons. https://creativecommons.org/licenses/by-sa/2.0 (https://creativecommons.org/licenses/by-sa/2.0)

Albany Surprise grapes
Image: MM, Public domain, via Wikimedia Commons.

Spur-pruned vine
Image: Michael Tampakakis/Pixabay.

Cane-pruned vines
Image: Man Vyi, Public domain, via Wikimedia Commons.