Pluots (Prunus hybrids)

What does this category of pluots and hybrid plums really include?

This category brings together fruit trees obtained by crossing different species within the genus Prunus. It includes genuine plum–apricot hybrids, but also European and eastern European selections derived from several species of diploid plum.

The word pluot is now often used loosely for any fruit appearing intermediate between a plum and an apricot. Genetically, this is not always accurate. The cultivars grouped here do not all share the same parentage, and some hybrid plums may contain no documented apricot ancestry.

The behaviour of a cultivar cannot therefore be predicted from its commercial name alone. Fruit texture, apricot aroma, flowering, pollination, winter hardiness, disease susceptibility and ripening season must be considered cultivar by cultivar.

This diversity is precisely what makes the group valuable. Some cultivars resemble exceptionally aromatic plums, others look more like dark-skinned apricots, while certain eastern European selections behave as early and colourful hybrid plum trees.

Pluot, plumcot, aprium, black apricot or hybrid plum?

Traditional hybrids between apricot and cherry plum

Some of the oldest known plum–apricot hybrids developed from crosses between the apricot and the cherry plum or myrobalan.

These hybrids did not necessarily originate in modern breeding programmes. Spontaneous seedlings could appear wherever apricots and cherry plums grew together, flowered simultaneously and were regularly propagated from seed.

The fruit frequently combines dark purple skin, very juicy and slightly acidic flesh, an attached stone and a genuine aroma of ripe apricot.

Fruit quality varies considerably because the group contains different seedlings and locally selected clones rather than one single uniform cultivar.

The Italian biricoccolo has a much older history than the modern pluot

The biricoccolo is an old Italian fruit that was cultivated long before the names pluot and aprium appeared.

It is generally associated with Prunus × dasycarpa and probably developed from hybridisation between apricot and cherry plum.

The fruit is often dark, sometimes slightly velvety, with flesh combining the juice and lively acidity of a plum with a clearly recognisable apricot perfume.

Italian biricoccoli should not be assumed to represent clones of one original plant. They may descend from several ancient hybridisation events selected locally and preserved through grafting in family gardens and orchards.

Their value is not merely historical. Good selections can combine distinctive flavour, robustness and excellent cooking quality, even when their fruit size or storage life does not match that of a modern commercial cultivar.

Black apricots from Armenia, the Caucasus and eastern Europe

Comparable traditional hybrids have been preserved in Armenia, central Asia, the Caucasus, the Balkans and different parts of eastern Europe.

They are variously described as black, purple or violet apricots and are generally associated with the hybrid group Prunus × dasycarpa.

The Armenian cultivar ‘Shlor-Tsiran’, whose name means plum–apricot, produces dark violet fruit with juicy and lively flesh reminiscent of cherry plum and a genuine apricot aroma.

These resources attracted breeders because certain forms flowered later, tolerated some spring frosts more successfully or displayed better disease behaviour than susceptible apricot cultivars.

Breeding programmes in Russia, Ukraine, Crimea, Bulgaria and neighbouring regions subsequently used similar material to obtain larger, more regular fruit adapted to continental growing conditions.

Eastern origin does not by itself guarantee exceptional winter hardiness or successful ripening in every European climate. The actual pedigree, flowering period, frost tolerance and harvest season of the cultivar remain more informative.

Modern hybrids between apricot and diploid plums

Modern hybridisation can involve apricot, Japanese or Chinese plum, cherry plum and hybrids that already possess a complex pedigree.

Selected seedlings may then be crossed again with plum, apricot or another hybrid to reinforce particular fruit or tree characteristics.

The objective is often to obtain fruit that is larger, firmer, more regular and easier to produce than early spontaneous hybrids.

The result may appear almost completely plum-like while retaining a distinctive apricot aroma, or remain closer to apricot in its flesh, skin and texture.

A multi-generation pedigree cannot be described reliably by a simple visual impression or one theoretical percentage.

Why cross plums and apricots?

The purpose of these crosses is not simply to create an unusual-looking fruit. Breeders try to combine characteristics that rarely occur together in one conventional cultivar.

The apricot aroma is real, but varies greatly between cultivars

The aroma of apricot is not produced by one single substance. It results from a complex combination of lactones, esters, terpenes, carotenoid-derived compounds and other volatile molecules.

A hybrid may retain high concentrations of some compounds associated with apricot while producing very little of others.

This explains why two cultivars with apparently similar parentage can possess completely different flavours.

Some hybrids release an obvious apricot perfume as soon as the fruit is cut.

In others, the apricot influence becomes noticeable mainly in the mouth or in the aroma remaining after the fruit has been swallowed.

Some genuine plum–apricot hybrids display almost no recognisable apricot perfume. Their value may instead lie in colour, sweetness, acidity, precocity, robustness or texture.

Apricot perfume develops mainly at full maturity

Many of the compounds responsible for apricot aroma increase during the final stage of fruit maturity.

A hybrid picked too early may already possess an attractive skin colour and firm edible flesh while remaining almost devoid of perfume.

The fruit may soften after harvest without developing the complete aromatic profile that it would have produced on the tree.

This explains why the same cultivar can taste exceptional when harvested fully ripe from a garden yet seem relatively ordinary when picked early for transport.

To evaluate a pluot or plum–apricot correctly, taste fruit that has reached physiological maturity rather than fruit that has merely softened during storage.

A hybrid does not express half of every characteristic from each parent

A direct hybrid receives approximately half of its genetic material from each parent, but this does not mean that every fruit characteristic will be exactly intermediate.

A seedling may possess almost entirely plum-like skin and flesh while retaining an intense apricot perfume.

Another may display velvety skin and apricot-like flesh while keeping the acidity, juiciness and attached stone of a cherry plum.

Later generations make theoretical percentages even less useful because hybrids may be crossed back to a plum, an apricot or another complex hybrid.

A relatively small part of the genome may exert a major influence on aroma, colour, fertility or disease response.

It is therefore more rigorous to identify documented parents and describe the characteristics actually observed in the cultivar than to rely on an approximate plum-to-apricot percentage.

Do not confuse eastern European hybrid plums with plum–apricot hybrids

Many eastern European hybrid plums were created by crossing cherry plum with Japanese, Chinese, Ussurian or other diploid Asian plums.

These cultivars may offer outstanding flavour, spectacular skin and flesh colours, very early maturity and excellent adaptation to continental climates.

None of these qualities proves that apricot occurs in their pedigree.

Orange flesh or a strong perfume should not be treated as genetic evidence either.

A cultivar may remain within this commercial category because it is an original and valuable Prunus hybrid, but its product page should describe it as a hybrid plum unless apricot ancestry has been reliably documented.

Which characteristics should be compared before choosing a cultivar?

Ripening season remains decisive in cool European climates

A cultivar may be completely winter hardy while remaining incapable of developing its full fruit quality during a cool summer.

Apricot perfume, sugar concentration and flesh colour depend strongly on light and temperature during the final stage of maturity.

A late cultivar selected in a continental region may tolerate winters much colder than those of western Europe yet still require a warmer and brighter summer to ripen successfully.

Winter hardiness and the ability to ripen under cool conditions are therefore separate characteristics.

For northern, maritime or elevated sites, prioritise cultivars whose early or mid-season maturity has been demonstrated in temperate European conditions.

View the Pluot and Hybrid Plum Harvest Calendar

The calendar is intended primarily for comparing cultivars. Actual dates vary according to country, region, exposure, rootstock, crop load and seasonal weather.

Improved frost tolerance is possible, but not automatic

Some black apricots and eastern European hybrids flower later or tolerate certain frost events better than conventional apricot cultivars.

This improvement was one of the historic objectives of crossing apricot with cherry plum and other hardy species.

It would nevertheless be incorrect to conclude that all pluots are more resistant to frost.

Some hybrids begin growing and flowering as early as Japanese plums or apricots.

Flowering date, intrinsic frost tolerance of the buds and flowers, duration of the cold event and stage of young fruit development must be considered separately.

An early hybrid planted in a frost pocket may be at greater risk than a later-flowering European plum growing only a short distance away.

Chromosome groups help explain pollination difficulties

Apricot, cherry plum and Japanese plum are generally diploid species, meaning that they possess two sets of chromosomes.

Many hybrids developed from these groups are also diploid or belong largely to the diploid plum gene pool.

This can allow pollination between certain Japanese plums, cherry plums and closely related hybrids, provided that their flowering periods overlap and they are genetically compatible.

European plums such as many gages, quetsches and damsons are generally hexaploid, with six sets of chromosomes.

Their different chromosome structure and frequently different flowering period mean that they should not be recommended automatically as pollinators for a diploid pluot or hybrid plum.

Chromosome number alone does not prove compatibility. It only helps identify which botanical groups are more plausible pollinating partners.

Pollination of interspecific hybrids requires particular attention

Interspecific hybrids can possess reduced pollen fertility because chromosomes inherited from different species do not always pair normally during pollen formation.

This problem is especially evident in some hybrids close to the first generation.

A tree may therefore flower abundantly and receive pollen successfully while remaining a poor pollinator for neighbouring trees.

It is important to distinguish the ability to receive pollen, the ability to produce viable pollen and genetic compatibility with another cultivar.

These three characteristics are related but not identical.

What can pollinate a pluot or plum–apricot hybrid?

The answer depends entirely on the cultivar and its pedigree. There is no universal pollinator for every hybrid within the genus Prunus.

Another hybrid flowering at the same time may be effective when it produces viable pollen and is genetically compatible.

Certain Japanese plums, cherry plums or eastern European hybrid plums may pollinate cultivars belonging predominantly to the diploid plum group.

This compatibility must still be confirmed cultivar by cultivar.

The presence of an apricot tree does not guarantee successful pollination.

The fact that a breeder once obtained a controlled cross between apricot and plum does not mean that every apricot will easily pollinate every plum–apricot hybrid in a garden.

European plums should not be recommended automatically because they are generally hexaploid and may flower at a different time.

Where reliable pollination information is unavailable, planting two unrelated diploid hybrids with strongly overlapping flowering periods is more prudent than relying on one arbitrary plum or apricot cultivar.

Why might a hybrid flower without producing fruit?

The absence of a compatible pollinator is the first possibility to investigate, but it is not the only explanation.

The cultivar may produce pollen of low fertility or its flowering period may fail to overlap sufficiently with the intended partner.

Low temperatures can prevent normal pollen germination and growth of the pollen tube.

Bees and other pollinating insects are also less active during cold, windy or continuously wet weather.

Frost can destroy the ovules or young fruit without immediately removing the petals, creating the impression of normal flowering before the small fruit stops developing.

A young tree may also flower before it has developed enough vigour and leaf area to retain a substantial crop.

Should the fruit be thinned?

Productive hybrids can set more fruit than the tree is able to ripen properly.

Numerous small fruits may remain crowded together on relatively thin branches.

Excessive crop load reduces fruit size, sugar concentration and apricot aroma while delaying maturity.

After natural fruit drop, leave enough space for the remaining fruit to develop without touching at maturity.

The correct spacing depends on the expected fruit size of the cultivar.

Remove malformed, damaged or poorly positioned fruit first, particularly where it is carried by a weak branch.

Thinning also reduces the risk of branch breakage and can improve crop regularity from one year to the next.

Are hybrid plums more resistant to disease?

Hybridisation can transmit useful tolerance of particular diseases, but it does not automatically create a tree resistant to every problem affecting plums and apricots.

Some black apricot genotypes have shown useful behaviour against brown rot and shot-hole disease compared with susceptible apricot cultivars.

This concerns specific selections and cannot be generalised to the whole category.

Pluots and other hybrids can still be affected by blossom and fruit brown rot, bacterial canker, shot-hole disease, leaf spots, aphids and the principal pests of plums.

A cultivar selected in a dry continental climate may behave differently during a persistently wet spring in western or northern Europe.

An open crown, moderate pruning, removal of mummified fruit and a well-drained planting position remain important even for a cultivar described as robust.

Brown rot, rain and fruit splitting

Brown rot can infect flowers during wet weather and cause the death of blossom clusters and short shoots.

Close to harvest, split or wounded fruit becomes especially vulnerable to fungal decay.

Very juicy and high-sugar hybrids may split when heavy rain or substantial irrigation follows a dry period.

Susceptibility to splitting is highly dependent on cultivar and cannot be predicted solely from skin thickness or flesh firmness.

Relatively consistent soil moisture, appropriate thinning and picking at the correct stage reduce aggravating factors without making a susceptible cultivar completely resistant.

Which rootstock should be chosen?

The rootstock should be selected according to the dominant parentage of the cultivar, documented compatibility and soil conditions.

The presence of apricot in the pedigree does not mean that an apricot rootstock is automatically the most suitable choice.

Many plum–apricot hybrids behave predominantly like diploid plums and are more commonly grafted onto plum-compatible root systems.

Read our guide to fruit-tree rootstocks

How should pluots and hybrid plum trees be trained and pruned?

Most hybrid plums and pluots crop on relatively young branches and on short fruiting structures that can remain productive for several years.

They should not automatically be pruned like peaches, whose crop depends much more heavily on shoots formed during the previous season.

An open-centred tree or a central leader with well-spaced framework branches can both provide sufficient light around the fruit.

Pruning should concentrate on removing badly positioned branches, dead wood, cankered sections and areas that have become excessively dense.

Avoid systematically shortening every shoot. Severe cutting stimulates excessive vegetative growth and may delay fruiting.

Large cuts are preferably made during dry weather while the tree is actively growing, reducing the period during which wounds remain vulnerable to wood diseases.

How can full maturity be recognised?

Skin colour is not always a reliable maturity indicator.

Some cultivars remain green, yellow-green or mottled when fully ripe, while others become darkly coloured several days before reaching their best eating quality.

Observe the background colour, slight softening of the flesh, development of aroma and ease of detachment.

The apricot perfume frequently becomes much stronger during the final days of maturity, making tasting essential.

Fruit exposed to the greatest amount of sunlight normally ripens first.

Several selective picking rounds provide much better quality than harvesting every fruit on the tree as soon as the first specimens are coloured.

A fruit picked too early may soften after harvest while remaining acidic, low in sugar and almost devoid of aroma.

Which hybrid should you choose?