nectarines

I’ve just returned from a South Island road trip, with the back seat of my car piled with Central Otago summer fruit and other regional delicacies destined to fill the fruit bowls and pantries of family and friends. Oh, and mine of course! I enjoyed popping into roadside stalls and also meeting the proprietors of the family-run orchard I order cases of fruit from each summer – it’s always nice to put a face to a name, especially when you live at opposite ends of the island we call home.

One thing I forgot to pick up on the return journey was a few extra white-flesh nectarines. To be honest, my loyalties are very much divided when it comes to stone fruit. I have my particular favourites amongst peaches, plums and apricots and eagerly await the arrival of each cultivar in season. But at a pinch, if allowed only one type of fruit while stranded on a desert island, my pick would be the white-fleshed nectarine. We had two trees in the garden as I was growing up, one by the chook run and one by the neighbours’ fence. The latter remains to this day and I really must get around to seeing if I can procure some stones to propagate from. I have no idea what cultivar they were, but the slightly ironically-named Goldmine was the standard of the era – belying its pale white flesh. Our fruit was freestone and had dark, pronounced red colouration around the stone – to this day, I swear fruit with this marking has far superior flavour than that without.

Popular with the fuzz-averse eaters amongst us, nectarines are essentially smooth-skinned peaches, with a single gene responsible for the presence or lack thereof – fuzzy skin is caused by the dominant allele and smooth skin by the recessive. I am a fan of the skin on peaches, but also subscribe to the line of thought that nectarines have the upper hand when it comes to flavour – nectarines possessing a sharper yet richer, more aromatic flesh quality than their fuzzy cousins. They also tend to be the first stone fruit to arrive on the shelves in late spring to early summer – welcome relief after months of apples and oranges. Although I’ve had dalliances over the years with stone fruit imported from the USA in the deep dark depths of our Southern Hemisphere winter, as the great British cook Nigel Slater says of imported nectarines and peaches “The further they travel, the more disappointing they generally are”. My mature self agrees wholeheartedly – there truly is no substitute for New Zealand grown – so why not make it home grown?

Nectarines: a short family history

Formally described as Prunus persica var. nucipersica (or var. nectarina), nectarines have a bit of a muddy history. Despite their smooth, plum-like skin, distinctive flavour and generally smaller fruit size compared with peaches, they are definitely not a peach/plum hybrid. They are likely to have arisen from and been domesticated alongside peaches in China some 2,000 to 4,000 years ago – modern genetic analysis backs this up. The first instance of nectarines in English literature dates from 1616 and there are mentions in pre-American Revolutionary War publications of the fruit being cultivated in America as early as 1768.

As a result of the process of pollination (and this includes both cross and self-pollination), any fruit produced by a peach or nectarine tree with seed carrying the recessive allele (for smooth skin) will germinate and produce a nectarine tree, and that carrying the dominant allele (for fuzzy skin) will germinate to produce a peach tree. Neat eh?

It is not uncommon, even in modern times, for nectarines to arise from peach trees via spontaneous natural mutations, commonly known as ‘sports’, where by chance a part of a plant produces foliage, flowers or fruit that differ markedly in appearance from that produced on the rest of the plant. A good example is the nectarine ‘Black Pearl’, which was found in Auckland, right here in New Zealand as a sport from a ‘Sanguine’ (blood) peach tree.

Suitable climates and growing conditions

Nectarines can be grown throughout New Zealand – they do have variable winter chilling requirements, ranging from 200-1200 hours depending on cultivar, hence you may find some inconsistencies in performance from region to region.

In the deep south, late frosts may wreak havoc at blossom time and some of the late-fruiting cultivars may struggle to ripen, while humid climates may exacerbate diseases such as brown rot.

Nectarines (and peaches) are generally not as long-lived as other stone fruit trees - in New Zealand, the lifespan of a nectarine tree will be up to about ten years in the North Island and the late teens or early twenties in the south.

Site selection and planting

Follow the general rules for fruit trees – select a sheltered but sunny site, nectarines will tolerate some shade but the fruit ripens best with adequate sun, and warm, dry conditions will help keep fungal diseases at bay. Well-drained soils are best, and although nectarine trees will handle a range of soil types, waterlogging is the one thing that will make them curl up their toes. If you have heavier soil types on your property (e.g. clay), you could try planting a tree grafted on to plum rootstock, as these trees will do better than a nectarine on its own roots in this instance. Some protection from wind is desirable and it’s best to also avoid frost-prone areas, as the blossom is susceptible to late frosts in the spring.

If you have the means to do so, take a leaf from the history books and grow your nectarine in a fan shape up against a north-facing brick or concrete block wall. This will provide not only the benefit of shelter but also increased heat units during flowering and fruiting. The only caveat is you’ll need to keep an eye on the watering, as the soil around walls tends to dry out quickly. Here’s some interesting reading material regarding the cultivation of so-called ‘wall peaches’ on an impressively large scale in 19th century France https://www.ediblegeography.com/solar-peach-walls/

Trees are best planted out in late autumn or winter and allow five to eight metres between trees. Work some compost or sheep pellets into the soil in the planting hole and water the tree in well. In the home orchard, plan to keep your trees below four metres in height for ease of picking and general management. Nectarines are trees are generally self-fertile but will benefit from having other peach or nectarine neighbours. Pollination is insect-assisted, so fingers crossed for warm, dry conditions at flowering. If lack of fruit set is continually an issue, you could try transferring pollen from flower to flower by hand with a paintbrush.

As with peaches, nectarines can be grown readily from stones, and while it’s quite likely they will grow true to the parent tree, there is always the unpredictability aspect provided by genetic variation. Who knows, you might even end up with something better! Seedling-grown trees are often hardier than their grafted or budded counterparts too, and will start producing around three years of age. If you don’t have time for DIY cultivation, your local nursery will likely stock a range of grafted nectarine trees, giving the advantage of producing a crop potentially earlier than seedlings, and on a rootstock tailored to suit your soil type – several dwarf cultivars are also available, which are suitable for pot culture.

It is not unknown for mature trees to produce in excess of 20-30 kg of fruit, and it is advisable to thin heavy crops to prevent biennial bearing (a heavy crop one year and next to nothing the following). Undertake this when the central stone begins to harden (split open a few immature fruits if you’re not sure about timing). Remove a sufficient number of fruit to allow the remainder to reach a good size without stressing the tree and also take into consideration the size and strength of each branch in regards to what it can carry to maturity.

Don’t forget to harvest nectarines when fully ripe, as the full sweetness, texture and flavour will not be obtained once the fruit is off the tree. As Nigel Slater says (again!) “An unripe nectarine is barely distinguishable from munching a rubber ball”.

Culture and care

For optimum crops, nectarines require some fertiliser inputs. This can be of a standard general fertiliser or an organic preparation, allowing 250-500 g per year of age for young trees, up to a total of 5 kg/tree at maturity. Split this into two or three applications, applied in spring and early summer. Don’t forget to spread this fertiliser before rainfall, or water it in well afterwards.

In terms of irrigation, make sure you keep the water up to your trees in the fruit formation period. Drip irrigation close to the soil is ideal, as sprinklers that project moisture up into the canopy are a party invitation for fungal diseases. Nectarines have a degree of drought-tolerance but it’s best not to let them come under water stress. Keep the area directly under the tree free from grass and weeds to prevent competition for water and nutrients – a layer of organic mulch may also be applied.

Pruning

An open-centre vase shape suits nectarines well as it ensures adequate light penetration and air movement through the canopy. At planting in the winter, choose two to three strong, well-spaced shoots and remove the rest of the wood.

Cut the remaining shoots back by a third and to an outward-facing bud, sealing all cuts immediately with pruning paint. This will be the only winter pruning required.

Upright shoots will develop from these initial shoots in the spring – later in the first summer you can select four or five of these to form the tree’s main leaders. Clear out any other vertical shoots in competition, as well as those growing in the centre of the tree.

The leaders will develop side branches, and from these you need to select flatter, horizontal-growing branches to be your fruiting arms. More upright-growing branches will need to be tamed by pruning into a flatter position or removed, so they don’t compete with the leaders. Trim the tips of the fruiting arms to encourage lateral growth and subsequent fruit production.

Nectarines fruit on the previous season’s lateral growth, so you need to keep encouraging the production of fresh new wood. Remove laterals that have fruited in their second year and thin out one year old laterals if there are too many. Keep an eye out and learn to distinguish fruit buds from leaf buds – the former are round and full-bodied, the latter are flatter and pointier. Being able to distinguish the two will help prevent you trimming off the following season’s crop!
If you’re keen to train your nectarine against a wall, the Royal Horticultural Society has some hints and tips, found here: https://www.rhs.org.uk/fruit/peaches/grow-your-own Just remember this is advice for the Northern Hemisphere, so south becomes north and adjust the months to suit the southern seasons!

Aim to make all maintenance pruning cuts while the weather is still warm and dry to prevent silver leaf (Chondrostereum purpureum) infection – February for earlier cultivars and as soon as possible following harvest for the later cultivars.

Pests, diseases and what to do about them

Ask anyone who grows peaches or nectarines what the number one disease issue is and it’s highly likely they will say it’s the dreaded leaf curl. Caused by the fungal pathogen Taphrina deformans, the symptoms are very obvious and somewhat unsightly – leaves begin to pucker inwards and become distorted with lumpy reddish protrusions. Exacerbated by damp conditions, severe infections can result in lesions on the flowers, deformed fruit and premature fruit drop.

Prevention is much better than a cure with this disease, so try a late-winter clean-up spray of copper oxychloride fungicide just as the buds begin to swell, and again after leaf fall at the end of the growing season. Some people prefer to pick off all the affected leaves by hand and destroy them, then wait for the tree to produce a fresh flush of (hopefully unaffected) new leaves, while others see the disease as a mere cosmetic inconvenience and leave the tree to it. Some cultivars have a degree of resistance to leaf curl and it may be worthwhile to seek these out, especially if you live in a humid climate.

Nectarines are also susceptible to the trifecta of fungal and bacterial diseases which also affect peaches and apricots:

Brown rot is the bane of the stone fruit grower’s existence – it is caused by the fungus Monilinia fructicola and causes unsightly patches of soft, brown rot that can penetrate fruit flesh right to the stone. The disease is exacerbated by warm, wet weather conditions at flowering and results in a host of symptoms including blossom blight, twig blight and canker and the aforementioned fruit rots – the speed at which the latter can march is astounding, under optimum conditions, fruit will decay in 48 hours and the rot can continue to spread post-harvest. You’ll probably be familiar with the regions of brown rot on fruit, decorated with fluffy tan or grey spores that if left unchecked, will result in black, mummified fruit that clings to the tree long after harvest. Part of managing this disease’s cycle is removing all mummified fruit and cankers from the tree and surrounding area, burning the material and applying a suitable fungicide during flowering.

Stone fruit canker and bacterial blast, caused by the bacterium Pseudomonas syringae pv. syringae shows up as limb dieback with weeping cankers and/or gummosis on branches and trunks. You may also see spots on the leaves and blast damage on flower buds and young shoots. Maintaining healthy, vigorous trees by carefully managing irrigation and nutrition can help stave off infection, as may copper sprays during the leaf fall period. Once infected, prune affected limbs back approximately 30 cm below the canker – until you hit clear, unstained wood (you may have to remove an entire branch or leader) – and seal with pruning paint.

Silverleaf is caused by the fungus Chondrostereum purpureum and is characterised by foliage of affected trees taking on a distinct silvery sheen. Infection takes place when airborne spores land on sapwood exposed by open wounds (e.g. at pruning), hence this activity should be avoided in damp weather and all cuts sealed immediately with pruning paint. Once the infection is present, it spreads throughout the tree and is usually fatal – you can try to limit its spread by pruning off affected wood and inserting TrichodowelsTM into the trunk.

In terms of insects, aphids can make an appearance in the spring on young growing shoots, and leafroller caterpillars, scale insects and mites may make themselves known, but are unlikely to cause major issues - neem or pyrethrum-based products applied according to label directions may be of assistance if they do.

Varieties: My top picks

Goldmine – medium-size freestone fruit, mid-late season (mid-February), white flesh, red over green skin colour. Vigorous growth habit. A heritage variety, said to originate from the Kaipara region of New Zealand.

Snow Queen – early season, large freestone red-skinned fruit with white flesh. Excellent flavour.

Black Pearl – a Sanguine (black/blood) peach sport, freestone, smooth dark burgundy skin and flesh. Late season.

Mabel® – a highly ornamental cultivar with pink blossom in spring followed by striking burgundy foliage. Fruit is red-skinned with white flesh, not always a heavy cropper but worth it as orchard eye-candy.

Fantasia – a mid-late-season (mid-February), low-chill cultivar suitable for warmer climes. Large, juicy, well-flavoured freestone fruit with red over yellow skin.

Pouto Gold – a New Zealand heritage cultivar available from the Koanga Institute. Small but sweet and juicy yellow-fleshed fruit, red over yellow skin.

Button Bright™ – a ‘Flatto®’ nectarine, good for novelty value and lunchbox stacking! Ornamental in spring with prolific blossom and a heavy cropper in mid-late summer, producing doughnut-shaped flat, red-skinned, yellow-fleshed fruit in perfect portion size.

Waimea Nurseries also stock three dwarf nectarines suitable for small spaces and container culture:

Flavourzee – mid-season, yellow flesh, self-fertile.

Garden Delight – low chill, yellow flesh, freestone, self-fertile.

Nectar Babe – low chill, yellow flesh, freestone, best when planted near another peach or nectarine for pollination. Produces attractive deep pink blossom in spring.

What to do with your crop

The nectarine’s number one claim to fame has to be as a superb fruit to eat fresh out of hand, preferably underneath the tree on which it grew. They bottle just as well, if not better than peaches as the skin stays intact and holds the flesh together nicely. The process is all the more easy if you choose a freestone cultivar of course (see Your Backyard Fruit Bowl – Apricots for the basic preserving method). They also dehydrate wonderfully in their natural state as halves or slices, or stewed and pureed for fruit leather.

On the savoury front, nectarines pair well with meat – particularly pork, bacon and poultry. Jane Grigson describes a nectarine sauce for poultry in her excellent Jane Grigson’s Fruit Book (Penguin, 1983). They are equally at home with cheese too, be it soft, milky fresh cheeses such as mozzarella or pungent blues. Thinking summer salads? Try adding sliced nectarines to your next leafy one and include fresh basil leaves or a mint-flecked lemony dressing alongside.

You can substitute nectarines for peaches in any number of hot and cold desserts calling for the latter – from peach Melba to peach pie. My favourite use for over-ripe or disappointingly flavourless nectarines is to flash them through the oven with some honey and spices to concentrate the flavour and bring them back into the realm of good taste.

Roasted nectarines

Preheat oven to 180°C

500 g halved nectarines – stoned and prepared weight, cut out any bruises or bad bits
1-2 tbsp of your favourite honey – a mild-flavoured type for sweet combinations, or try Central Otago thyme honey with the thyme leaves suggested below for an accompaniment to serve with meat dishes.
Optional extras: a split and scraped vanilla pod, a cinnamon stick, a few strips of lemon peel or 1-2 tsp grated lemon rind, a scattering of thyme leaves and a knob of butter.
A little water – 1-2 tbsp.

Place the halved nectarines cut side up in a baking dish and add a little water to the base of the dish. Drizzle with the honey and tuck in or scatter over one of the additional flavourings suggested.

Bake in the oven for approximately 40 minutes, basting with the cooking liquid halfway through. Serve warm or at room temperature as a dessert or side dish for meat. Leftovers will store in a covered container in the fridge for up to three days.


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.

The New Zealand Tree Crops Association is a voluntary organisation promoting interest in useful trees, such as those producing fruit, nuts, timber, fuel, wood, stock fodder, bee forage and other productive crops. Find out more about the NZTCA here: https://treecrops.org.nz/
Disclaimer: the information supplied above is of a general nature and provided as reference material only. In regards to pest and disease control, please consult your agrichemical consultant for suitable products, application rates and further region-specific information.

Image credits
Nectarines on tree - Fruchthandel_Magazin via Pixabay.com
Nectarine fruit - Bruno /Germany via Pixabay.com
Black Pearl nectarine – A & B Phillips