Peaches

   The ripest peach is highest on the tree
- James Whitcomb Riley, American writer and poet

There’s not much that beats a ripe peach on a hot summer’s day – especially if it is eaten standing in the shade cast by the tree itself. The peach tree of my childhood grew on an overgrown part of our hilly section and bore very small but distinctively flavoured golden-fleshed fruit. It was probably just a random seedling, but three decades passed before I tasted similar fruit again, this time from a friend’s orchard, another small, golden-fleshed peach that had been named ‘Madeline’ after the smallest of the Parisian schoolgirls in Ludwig Bemelmans’ well-known 1939 classic of the same name.

As versatile as a fresh dessert fruit to eat out of hand as they are for bottling and drying, peaches are as useful as they are diverse with their white to yellow to blood-red range of flesh colours. There’s a peach to suit every palate, climate and garden. 

Peaches: a short family history

Peaches (Prunus persica) are native to and were first domesticated and cultivated in northwest China and to this day, China produces the majority of the world’s commercial peach crop. The species epithet persica relates to the movement of peaches from Asia to the Middle East via the Silk Road. Europeans first encountered peaches in Persia, hence the name, with the Greeks and Romans then transporting them throughout Europe. They are an extremely diverse group, with several hundred cultivated varieties.

New Zealand has a strong affinity with peaches, as they were found already growing here around marae sites and other coastal settlements when the first passenger ships arrived in the early 1800s. The earliest European visitors to our shores probably left peach stones behind, beginning the fuzzy fruit’s legacy in Aotearoa. To this day, the Koanga Institute carries, amongst others, a collection of ‘River’ heirloom New Zealand peaches from around the Kaipara Harbour, where peach trees once grew wild in veritable thickets around missions and early settlements.

People either love or loathe the fuzzy, sometimes chewy skin on peaches - it can be somewhat polarising. I think the admirers outnumber the haters however, and Aotearoa has longstanding affiliations with certain varieties – Golden Queen, found growing in 1909 in a Tauranga garden, which went on to be the darling of our canning industry, and the ruby-fleshed Sanguine or blood peach, stalwart of many a back garden and pantry shelf. Several modern dwarf cultivars can be grown, and cropped successfully, in large pots, so even those in small urban sections can consider adding a peach to their patio. 

Suitable climates and growing conditions

Peaches can sometimes be finicky to grow - in the southern regions, late frosts attacking early blossom may affect fruit set, conversely, warmer temperatures further north may provide insufficient chilling hours and pesky rots can decimate ripening crops. Luckily there are plenty of cultivars to choose from, with something to suit just about every climate.  

Peaches have variable winter chilling requirements, ranging from 200-1200 hours depending on cultivar. Modern dwarf cultivars require the least, and hardier peaches such as the Sanguine (formerly Blackboy) peach also tend towards the lower-chill end of the scale and are suitable for growing throughout New Zealand.  

Peaches are, in general, not as long-lived as other stonefruit trees. In New Zealand, the lifespan of a peach tree will be up to about ten years in the North Island and the late teens or early twenties in the South. Trees will begin to crop about two to three years after planting.

Site selection and planting

Follow the general rules for fruit trees. Select a sheltered but sunny site, as peaches 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 peach trees will handle a range of soil types, waterlogging is the one thing that will make them curl up their toes quickly. If you have heavier soil types on your property (e.g., clay), you could try planting a tree grafted onto plum rootstock, as these trees will do better than a peach on its roots in this instance. Some protection from wind is desirable - shelter from a nearby hedge or shelterbelt where the constituent trees are well-spaced is ideal. It’s best to also avoid frost-prone areas, as the blossom is susceptible to late frosts in the spring.

Trees are best planted out in late autumn or winter, allowing five to eight metres between trees. Work some compost or sheep pellets into the soil in the planting hole and water the tree in the well. In the home orchard, plan to keep your peach trees below four metres in height for ease of picking and general management. Peach trees are by and large self-fertile, so if you only have room for one, that’s OK, but there’s no harm in planting several within reasonable proximity either. Pollination is insect-assisted, so fingers crossed for warm, dry conditions at flowering.   

Many peaches are easily propagated from stones, and although there will still be natural variation amongst the offspring, they usually grow reasonably true to type. If you have a friend with a peach tree of admirable pedigree, ask them nicely for a bag of stones at bottling time (or with a bit of luck, they might turn up on your doorstep with a bag of fruit!). On the internet, methods abound for germinating fruit stones. 

You can easily germinate peaches from stone at home. It’s best to plant the stones ‘fresh’, fairly soon after eating the fruit, or at least before they dry out completely. Grab a medium-sized plant pot for each variety, label it, fill it with potting mix and plant the stones about an inch deep in the mix. If you do this in late summer - early autumn and leave them somewhere semi-sheltered but exposed to the elements, there’s enough time for exposure to some decent winter chill to break the dormancy of the inner kernel, which should sprout readily come spring. Plant quite a few for safety in numbers. Seedling-grown trees sometimes take a bit longer to fruit but are often hardier than their grafted or budded counterparts.  

Most nurseries stock a good range of the most popular peach cultivars, with grafted trees giving the advantage of producing a crop sooner and often a rootstock tailored to your soil type. Seedling trees will start producing around three years of age – although I have heard of mollycoddled trees producing in year two. You can expect some sizeable crops from mature trees, easily over 20 kg. To prevent biennial bearing (a big crop one year then a small crop the next), thinning of heavy crops is desirable – 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.             

Culture and care

For optimum crops, peaches require some fertiliser inputs, ideally early in the growing season. 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 provide ideal conditions for fungal diseases to take hold. Peaches 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 peaches 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.

Peaches 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 from trimming off the following season’s crop.        

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

Peach cultivars vary significantly in their susceptibility to pests and pathogens, from the very hardy, disease-resistant Sanguine (which even shrugs off the dreaded leaf curl, Taphrina deformans), to more delicate cultivars which may need a greater degree of coddling to produce a decent crop.

Leaf curl is probably the most recognisable peach tree ailment. The symptoms of this fungal disease 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 for 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. I have a vigorous seedling golden-fleshed peach that appears to be as hardy as Sanguine in its leaf-curl resistance, even under high-humidity West Coast conditions, so I’ll be grafting and passing on trees to others in the future.

Brown rot is the bane of the stone fruit grower’s existence and the heart-breaking destroyer of many a close-to-harvest peach crop. 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, the 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 late-winter clean-up spray of a copper fungicide formulation just as the buds begin to swell.

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, trunks and sometimes fruit stems at harvest. 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. Dispose of all infected material, preferably by burning – do not mulch or compost.

Silverleaf is caused by the fungus Chondrostereum purpureum and is characterised by the 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

Wiggins – an heirloom variety and my absolute pick of the bunch. Large, green-skinned, white-fleshed fruit which can have a pink blush and pink around the stone. Early season – ripe January in central New Zealand.

Sanguine – a hardy favourite that crops well right around the country. Resistant to leaf curl and grows true from stones. Tawny brown skin with deep red flesh – also freestone, so a bottler’s dream. Late season (March).

April White – a very late-season white fleshed peach with pink-blushed skin. Trees crop heavily and have a good degree of leaf curl resistance and moderate vigour.

Golden Queen – Heinz Wattie’s stalwart canning variety whose early roots were embedded in the Tauranga garden of a Mr Edwin Reeve. As good for eating as it is for bottling, the only downside is that it’s clingstone. Golden skin and flesh ripen late season (March).

Gordon’s Glory – I first came across this late-season beauty on a roadside stall near Southbridge in Canterbury. Ripening March, it has dense golden flesh similar to a Golden Queen, but an attractive red blush on the skin. A heavy cropper that is also resistant to leaf curl.

Flatto’ peaches – a recent introduction to New Zealand, these doughnut-shaped fruit have actually been around for centuries. Handy for stacking in lunchboxes and a boon for packaging companies, look out for these tasty peaches with tiny stones – cultivars available commercially through Waimea Nurseries include Sweet Bonnet™ (yellow flesh) and Sweet Cap™ (white flesh).

Dwarf peaches – small enough to be grown in containers, so ideal for patio gardeners, there are several cultivars available. Look for Bonanza, Garden Lady, Honey Babe and Pixzee (yellow flesh) and red-blossomed Rose Chiffon (white flesh).

What to do with your crop

Peaches are the king of bottling fruit – use the method in Your Backyard Fruit Bowl – Apricots but decrease the amount of sugar to ¾ cup sugar: 3 cups water. When I find I have copious leftover syrup, I either use this to bottle other fruit or you can also reduce leftover syrup, add some lemon juice and then strain and bottle it as cordial.

As fruit leather, mix with up to 50% mashed banana, stewed apple or pear before blending, use some leftover fruit syrup if the mixture needs thinning – dehydrate for about 10 hours on a medium heat setting.  

If you’re not into baking, how about grilled peaches as a stunning summer dessert? Speed up the process and cut down on mess by using a sandwich press, lined with baking paper. Add a little butter and brown sugar, and away you go. Peaches also make a great tarte Tatin, and have the advantage of taking less time to cook down for this than the traditional apples. 

Although you don’t often think of peaches as a jam fruit, I made a memorable batch of citrus-influenced peach and nectarine jam a few years back, perfect if you have some surplus fruit looking for a purpose. Stash a few jars away in the pantry and it’s guaranteed to brighten a gloomy winter’s morning.

Peach and citrus conserve

  • 1.5 kg peaches, or a mixture of nectarines and peaches (prepared weight).
  • 900g sugar
  • 2 oranges and 1 lemon, or use a mixture of your favourite citrus or whatever’s in season.
  • 1 tbsp orange blossom water (find this in Middle Eastern groceries and specialist food shops)
  • 3 tbsp orange liqueur

You’ll also need some second-hand commercial glass jars – you’ll re-use about five 300-400 g jam or peanut butter jars with sound, unscratched, (and undented) lacquered metal lids for this recipe.

You can use some slightly underripe fruit in the mix if you have windfalls or otherwise damaged fruit, just prepare it carefully and remove any bruised spots.

Place the sugar in a large non-reactive bowl, big enough to take all the ingredients. Slice the citrus fruit, removing any pips, and place in a food processor fitted with the chopping blade. Process until finely chopped and then add to the sugar, and stir well.

Stone the peaches and remove any damaged sections. Chop into large chunks and add to the sugar/citrus mixture. Stir well and cover, then refrigerate overnight.

Next day, preheat your oven to 125°C. Wash jars and lids in hot soapy water, drain, then place jars on their side on oven racks. Heat for at least 30 minutes to sterilise. If you have a metal preserving funnel, wash this along with the jars and pop it in the oven too.

Place the peach mixture into a preserving pan or large saucepan and cook over moderate heat until it reaches a gentle simmer. Stir frequently with a wooden spoon, and cook down until the mixture forms a thick gel on the back of the spoon – this will take about 45 minutes. At the 30-minute mark, pop a couple of saucers in your freezer.

Place metal lids in a small saucepan and cover with water. Drop in a ladle and set of tongs too. Bring to the boil then simmer at least 10 minutes to sterilise. Remove the hot jars from the oven using your sterilised tongs and place them on a wooden chopping board. Place the preserving pan on a heat-resistant mat near the board with the jars. Remove your metal funnel from the oven with tongs and place in the mouth of a jar. If your funnel is plastic, rinse briefly with boiling water (to be honest, I recommend investing in a metal funnel). 

Test to see if the jam is ready by dropping a teaspoonful on a cold saucer from the freezer. Let it cool slightly, then run your finger through the jam. If wrinkles and a clear path appear, the jam is ready to bottle.

Fill the jars with hot jam to within 5 mm of the rim. Wipe any bits of fruit from the rim using a clean cloth, dipped in boiling water. Pick up a hot lid from the saucepan with your tongs and drop it on top of the jar. Wiggle it in place and line up the thread – screw it down firmly. Grab a tea towel – wrap this around the jar and tighten the lid all the way. Line another spot on the bench with tea towels and place the finished jars on the towels to cool – if you put them straight on a cold surface they will crack, game over. 

Leave the jars on the bench for at least 24 hours – properly sealed jars will have concave lids. Clean any spilt jam from the jars using tepid water (hot water can crack the jars and your hard work will go down the drain) and a cloth - a nail brush also works wonders. Refrigerate any jars that haven’t been sealed for immediate use.


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.

Anna-Marie Barnes is an active New Zealand Tree Crops Association member who endeavours to grow and preserve as much of her 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/

 

Image credits

‘Flatto’ peaches – Mike Ljung via pixabay.com

Peaches on branch 2 – Hans Benn via Pixabay.com

Yellow peaches - Anna Armbrust via Pixabay.com