Varieties and Cultivars of Plum

2.1. European Plum (Prunus domestica)

This is the most widespread and diverse group in temperate‑climate countries. The European plum is a polyploid species (hexaploid, 2n=48) that is thought to have arisen from natural hybridisation of the diploid cherry plum (Prunus cerasifera) and the tetraploid blackthorn (Prunus spinosa) (Westwood, 1993; Mandal, 2021). This is why it combines traits from different ancestors.

Key characteristics:

• Cold hardiness: In general, European plums are more winter‑hardy than Asian ones and are suitable for regions with cold winters. They have a higher winter chill requirement (800–1000 hours below 7 °C to break dormancy) (Hill & Perry, 2011).
• Soils: They tolerate heavy clay soils better than other plums, although they prefer well‑drained loams (Hill & Perry, 2011).
• Fruits: Often oval or egg‑shaped, with firm flesh that separates easily from the stone (freestone). They contain more sugar and dry matter, making them ideal for drying (producing prunes). The flesh is usually yellow or greenish.
• Flowering time: They bloom later than Asian plums, which helps them avoid damage from spring frosts.
• Canopy shape: Trees usually have a more compact, upright or pyramidal crown.

Main cultivar groups within European plum:

1. Prunes (Hungarian plums): The best‑known group. Fruits are dark blue or purple, elongated, with a waxy bloom. The flesh is firm and sweet. These are the cultivars used for prune production (Choudhary, 2003). They are also excellent for jams and compotes. Examples: Hungarian domestic, Italian Hungarian (Mandal, 2021).

2. Green Gages (Renclods): Fruits are round, often green or golden‑yellow, with very juicy, tender, honey‑sweet flesh. These are perhaps the most delicious European plums for fresh eating, but they are less transportable and more demanding in care (Choudhary, 2003). The cultivar ‘Green Gage’ is considered a taste standard (Mandal, 2021).

3. Mirabelles: Small‑fruited, yellow plums with firm flesh and a small stone. They are valued for their high pectin content and are used for making jams, preserves, and the famous mirabelle brandy (Mandal, 2021).

4. Egg plums (Egg plums): Large, yellow or red fruits of egg‑shaped form. They are mainly used for canning and compotes.

2.2. Asian (Japanese) Plum (Prunus salicina)

This group originates from China but became widely known thanks to breeders in Japan and later in the United States. Today it is the main group for warm regions and for commercial fresh‑market plum production (Gull et al., 2023).

Key characteristics:

• Heat‑loving: Less winter‑hardy than European plums. They have a lower chill requirement (250–700 hours), so they break dormancy earlier and flower earlier, making them vulnerable to spring frosts (Hill & Perry, 2011). Recommended for regions with mild winters (USDA zones 6–9).
• Soils: Prefer light, well‑drained sandy loams and loams.
• Fruits: Large, often heart‑shaped or round, with juicy, aromatic flesh. The stone usually adheres to the flesh (clingstone). Skin colour can be yellow, red, purple, or almost black. Taste ranges from sweet‑tart to very sweet. These plums are not suitable for classic drying.
• Canopy shape: Trees often have a more spreading crown, requiring more space and formative pruning (Hill & Perry, 2011).

This group is renowned for its early bearing – many cultivars start fruiting in the third or fourth year after planting (Mandal, 2021). The famous American breeder Luther Burbank created many still‑popular Japanese plum cultivars, including the celebrated ‘Santa Rosa’ (Westwood, 1993).

2.3. American Plums and Hybrids (Prunus americana and others)

This group includes both wild species and cultivars bred from them. They are a real boon for gardeners in northern regions (USDA zones 3–5).

Key characteristics:

• Exceptional cold hardiness: Many species and hybrids withstand frosts down to ‑40 °C. They are ideal for areas with severe winters where European and Japanese plums freeze out.
• Low maintenance: They can grow on a wide range of soils, often on those too wet or heavy for other plums (Hill & Perry, 2011).
• Fruits: Usually small to medium‑sized, red, yellow, or dark blue. The taste varies from sour to sweet, often with astringency, so they are mostly used for processing (jams, jellies, sauces) or eaten fresh in processed form.
• Shrubby form: Many species have a shrubby habit and produce suckers, which is convenient for hedges but requires control.

Of particular interest are American hybrids obtained by crossing American species with Asian or European plums. They combine the best qualities: winter hardiness from the “American” parent and flavour from the “Asian” parent (Hill & Perry, 2011).

2.4. Other Important Species and Modern Hybrids

• Blackthorn (Prunus spinosa): A wild thorny shrub that produces small, astringent dark‑blue fruits. It is used as a rootstock for cultivated varieties and also for creating hybrids with European plum (Westwood, 1993; Kurennoy, 1985).
• Cherry plum (Prunus cerasifera): This is a diploid species that was one of the ancestors of the European plum. Cherry plum itself produces small sour fruits, but modern large‑fruited cultivars (e.g., hybrid cherry plum) are very popular in southern regions. They are early‑bearing, productive, and undemanding (Potapov, 2000; Trunov, 2012).
• Pluots, apriums, and plamcots: These are interspecific hybrids between plum and apricot. A pluot is a hybrid with mostly plum characteristics (75% plum, 25% apricot), while an aprium is the reverse (Hill & Perry, 2011). The fruits of such hybrids are often sweeter and more aromatic than those of ordinary plums and have a unique flavour. They require special pollination and care conditions but are of great interest to enthusiast gardeners.

How does this help you choose a cultivar?

A simple rule: for most regions of Russia, Belarus, and Ukraine, especially those with cold winters, the best choice is locally adapted cultivars of European plum or American hybrids. If you live in a southern region with mild winters, you can confidently choose among Asian (Japanese) cultivars, which will reward you with large, juicy fruits. For guaranteed yields in harsh conditions, look to American hybrids or cultivars bred from Prunus ussuriensis.

Understanding these basic groups is your key tool for avoiding mistakes when buying a sapling and choosing a tree that will truly grow and bear fruit in your climate. In the next chapter we will break down a detailed step‑by‑step algorithm for selecting a specific cultivar.

Step 1. Assess your climate: winter hardiness and chill requirement.

This is the most important step, as it eliminates unsuitable options.

Task 1.1: Determine the hardiness zone (USDA zone) for your region. Find out what minimum temperatures occur in your area in winter. If winters are severe (down to ‑35…‑40 °C and lower), your choice is American plums and their hybrids, as well as certain exceptionally hardy European plum cultivars (especially those with Ussuri plum in their pedigree). For temperate climates (down to ‑25…‑30 °C), most European plum cultivars will do. For warm regions with mild winters (down to ‑15…‑20 °C), the door is open to Asian (Japanese) plums.

Task 1.2: Evaluate the winter chill requirement (Chilling Hours). Each cultivar has a specific number of hours (at temperatures below 7 °C) that it must “serve” in winter for proper spring awakening. European plums have a high requirement (800–1000 hours), Asian plums a low one (250–700 hours) (Hill & Perry, 2011). If you plant a low‑chill cultivar in a cold region, it will wake up too early and be hit by frost. If you plant a high‑chill one in a warm region, it will not break dormancy and will flower poorly (Choudhary, 2003). Check this parameter for cultivars available in your area.

Conclusion after Step 1: You have determined which plum group (European, Asian, or American) is suitable for your climate.

Step 2. Decide on the main purpose for using the fruit.

Ask yourself: what do you want the plum for?

• Fresh eating (dessert cultivar): Look for cultivars with juicy, sweet, aromatic flesh. Asian plums often have tender, very sweet flesh; European plums have firmer flesh, but some green gages and certain prunes are also excellent fresh.
• Processing and preserving (jams, compotes): Cultivars with firm flesh that does not break down during cooking and a bright sweet‑tart flavour are well suited. Many European cultivars, especially prunes, fit here.
• For drying (prunes): You need cultivars with high sugar and dry matter content, firm flesh, and a small, easily separated stone. These are classic Hungarian plums (the “Prune” group) (Choudhary, 2003).
• Universal cultivars: Many modern European plum cultivars are good both for fresh consumption and for processing.

Conclusion after Step 2: You have narrowed the search by fruit quality characteristics.

Step 3. Learn about the pollination requirements of your cultivar.

The vast majority of plum cultivars are self‑sterile (Hill & Perry, 2011; Gull et al., 2023). This means that a single tree, even of the best cultivar, will not produce a crop without a neighbouring pollinator cultivar of the same species (European with European, Asian with Asian).

Task 3.1: When buying, always ask whether the cultivar is self‑fertile, partially self‑fertile, or self‑sterile.

• Self‑fertile cultivars (few, e.g., some old European varieties) can set fruit from their own pollen, but even they benefit from a pollinator.
• Partially self‑fertile will give a small crop without a pollinator, but for full production they need a partner.
• Self‑sterile (the majority) absolutely require a pollinator cultivar.

Task 3.2: Choose at least two cultivars of the same species that flower at roughly the same time. Flowering time can be found in the cultivar description or from the local nursery. The distance between them should be no more than 40 metres, preferably 10–20 metres, so that pollinating insects can easily transfer pollen (Hill & Perry, 2011; Martin, 2019).

Conclusion after Step 3: You ensure future harvests by properly combining cultivars.

Step 4. Check disease and pest resistance.

This factor is especially important in regions with humid climates where fungal diseases such as moniliosis, clasterosporium disease (shot hole), and sharka (Plum pox virus) are widespread (Seethapathy et al., 2023).

Task 4.1: When selecting a cultivar, pay attention to the description, which indicates its resistance or susceptibility to major diseases. Many modern cultivars are bred for combined resistance. Prefer such cultivars to minimise the number of treatments.

Task 4.2: Find out which diseases are a problem in your region and choose cultivars resistant to them. For example, resistance to sharka (Plum pox virus) is a critical trait for many European regions (Mandal, 2021).

Conclusion after Step 4: You choose a cultivar that is easier to care for and reduce the risk of crop loss.

Step 5. Consult local specialists.

The most reliable source of information is local nurseries, gardening societies, and experienced gardeners in your region.

Task 5.1: Ask at local nurseries which cultivars grow and fruit best in your area.

Task 5.2: Look at which cultivars your gardening neighbours are growing. That will be the most visual and practical answer to the question “which cultivar to choose”.

Conclusion after Step 5: You obtain time‑tested, locally adapted information that takes into account all the local nuances not described in general catalogues.

Summary: Your checklist for buying a sapling

1. Species: European, Asian, American (depending on climate).

2. Winter hardiness and chill requirement: Matches your region.

3. Purpose: Fresh eating, processing, drying.

4. Pollination: Self‑sterile? — needs a pollinator of the same species and flowering period.

5. Disease resistance: Preferably high resistance to the most common diseases in your area.

Following this algorithm, you will not make a mistake and will lay the foundation for a healthy, productive orchard that will delight you for many years. In the next chapter we briefly review how cultivars are distributed across major world regions to give you a global picture.

4.1. Europe

Europe is the homeland and main centre of cultivation for European plum (Prunus domestica). The greatest diversity of cultivars of this group is concentrated here.

• Central and Eastern Europe (Germany, Poland, Czech Republic, Hungary, Romania, Serbia, Bulgaria): These countries traditionally grow cultivars with high winter hardiness, suitable for continental climates with cold winters. The basis of the assortment consists of prunes (Hungarian types) (especially for drying and brandy production) and local old cultivars adapted to local conditions. In Germany, for example, the cultivar ‘Hauszwetsche’ occupies an important place, known for its undemanding nature and productivity (Mandal, 2021).
• Southern Europe (Italy, France, Spain): Here, in milder climates, Japanese plums (Prunus salicina) are grown alongside European ones (Gull et al., 2023). In Italy and France, much attention is given to fresh‑market cultivars – large‑fruited, attractive, with dessert flavour. Classic French cultivars such as ‘Reine Claude Verte’ (Green Gage) and ‘Mirabelle’ from Lorraine are flavour benchmarks and remain popular (Choudhary, 2003; Westwood, 1993). France is also actively breeding interspecific hybrids (pluots).

Key problem in Europe: The spread of sharka virus (Plum pox virus) seriously limits the cultivation of susceptible cultivars, especially in the Balkan countries (Romania, Bulgaria, Serbia), where plum production declined significantly in the past due to this disease (Mandal, 2021). Therefore, breeding for sharka resistance is actively pursued in Europe.

4.2. Asia

Asia is the homeland of both Japanese plum and many species of European plum.

• China: China is the undisputed world leader in plum production, accounting for more than half of the world harvest (Mandal, 2021). The main species in China is Japanese plum (Prunus salicina). Numerous cultivars have been developed both for the domestic market and for export. Chinese breeding focuses on large, transportable fruits with good shelf life, suitable for long‑distance transport (Gull et al., 2023; Mandal, 2021).
• Japan: In Japan, Japanese plum (Prunus salicina) is also the main crop. Cultivars with white or pink flesh, high sugar content, and low acidity – so‑called “honey” plums – are highly prized. Japanese cultivars are distinguished by exceptional flavour and attractive appearance (Westwood, 1993).
• Central Asia and the Caucasus: These are regions where plum has an ancient history. Alongside cultivated cultivars, wild species – cherry plum (Prunus cerasifera) and blackthorn (Prunus spinosa) – are of great importance, used as rootstocks and in breeding. Local cultivars of European and Asian plums often have high drought and heat tolerance (Westwood, 1993).

4.3. North America

North America has a unique situation. Alongside introduced European and Japanese cultivars, there is a rich group of native species (Prunus americana, P. nigra, P. angustifolia, and others). American species are renowned for their exceptional cold hardiness, but their fruits are often smaller and more sour than those of cultivated varieties.

However, thanks to the efforts of breeders (notably Luther Burbank), American hybrids were created that combine the winter hardiness of native species with the large fruit size and flavour of Japanese and European plums (Hill & Perry, 2011; Westwood, 1993). These hybrids are most popular in the northern US states and Canada (USDA zones 3–5). California, with its mild climate, is a world centre for production of Japanese plums and pluots for the fresh market (Hill & Perry, 2011).

4.4. Other Regions

• South America (Chile, Argentina): Chile and Argentina are major plum exporters, supplying the world market during the northern hemisphere winter. The main cultivars here are Japanese plums for fresh consumption, as well as European cultivars (especially ‘D’Agen’) for prune production (Gull et al., 2023).
• South Africa and Australia: These regions also have active plum production for export. The assortment is based on Japanese plums and pluots adapted to local climatic conditions (Mandal, 2021).

4.5. Cultivars for Russia

Russia is a country with a huge diversity of climatic zones, so plum breeding here proceeds in several directions.

• Southern regions (Krasnodar Krai, Rostov Oblast, Crimea, North Caucasus): Most cultivars of European plum (various prunes, green gages) and Asian (Japanese) plum, as well as hybrid cherry plum, are grown successfully here. The State Register of Breeding Achievements of the Russian Federation for these regions includes many cultivars that combine high fruit quality with productivity and disease resistance (Trunov, 2012).
• Central Russia and the Middle Belt (Moscow, Vladimir, Ryazan, Voronezh, and other regions): This is the main region for amateur gardening. Here winter hardiness becomes crucial. Leading cultivars are bred from Prunus domestica but with the involvement of frost‑resistant species such as Ussuri plum (Prunus ussuriensis). The State Register for this region includes well‑known cultivars such as ‘Hungarian Moscow’, ‘Early Red’, ‘Kolkhoz Renclod’, ‘Pamyat Timiryazeva’, ‘Eurasia 21’, and ‘Smolyanka’ (Trunov, 2012; Potapov, 2000). These cultivars are distinguished by good winter hardiness, relative disease resistance, and stable fruiting.
• Northern regions, Ural, Siberia, and the Far East: In these harsh conditions, plums are grown that can withstand frosts down to ‑40 °C and lower. The basis of the assortment here consists of American hybrids and cultivars of Ussuri plum (Prunus ussuriensis) and its hybrids. Cultivars for these regions – ‘Altai Jubilee’, ‘Vika’, ‘Dolinskaya Krasavitsa’, ‘Khabarovsk Early’ – often have small but sweet fruits and are highly winter‑hardy (Trunov, 2012; Kurennoy, 1985). They are the result of breeding work at the Research Institutes of Horticulture in Siberia and the Far East.

Important practical conclusion: For gardeners in Russia, the choice of cultivar is primarily determined by the climatic zone. The most reliable solution is to choose regionally adapted cultivars from the State Register of Breeding Achievements for your region. This guarantees that the cultivar has been tested in local conditions and can produce stable yields.

In the next concluding chapter we will analyse typical mistakes when choosing a cultivar and answer frequently asked questions.

5.1. Common Mistakes in Cultivar Selection

Mistake 1. Buying a “pretty” cultivar without regard for climate.

This is the most frequent and most unfortunate mistake. Seeing large, juicy fruits of a southern cultivar in a catalogue, the gardener buys it for his garden in the middle belt. The tree may grow, but it will flower and fruit poorly, and in a harsh winter it will freeze. Always choose cultivars that are adapted to your region. Remember: the climatic zone is the primary filter (Hill & Perry, 2011; Westwood, 1993).

Mistake 2. Planting a single tree (ignoring pollination).

When buying one sapling, the seller may say the cultivar is “self‑fertile” and does not need a pollinator. Even if that is true, the yield from a single tree will be much lower than with cross‑pollination with another cultivar. The solution: always plant at least two cultivars of the same group (two European or two Japanese) that flower at the same time (Hill & Perry, 2011; Martin, 2019).

Mistake 3. Wrong choice of pollinator cultivar.

You plant ‘Hungarian’ and ‘Green Gage’ thinking they will pollinate each other. In most cases – yes, but not always! Cultivars must be of the same species. European plum (Prunus domestica) will not effectively pollinate Japanese plum (Prunus salicina) and vice versa. Always check the species identity of the cultivar, not just its name (Gull et al., 2023).

Mistake 4. Ignoring flowering times.

Even two cultivars of the same species may not suit each other if one flowers two weeks earlier than the other. By the time the second cultivar opens its flowers, the first’s flowers will have faded. When selecting pollinators, always compare their flowering periods. This information can be found in the cultivar description (Mandal, 2021; Westwood, 1993).

Mistake 5. Wrong choice of cultivar for the intended use.

Some gardeners try to dry dessert cultivars with juicy, soft flesh. The fruits do not dry but rot. Each use has its own suitable cultivars. For drying, only prunes (with firm, dry flesh and high sugar content) are suitable. For fresh eating, dessert cultivars (Choudhary, 2003).

5.2. Frequently Asked Questions (FAQs)

Question 1: What is “chill requirement” (Chilling Hours) and how do I find it out?

Answer: It is the number of hours (usually at temperatures below 7 °C) that the tree must “experience” in winter in order to break bud dormancy and flower properly in spring. European cultivars have a high requirement (800–1000 hours), Japanese cultivars a low one (250–700). This information can be found in the cultivar description or obtained from the seller. Planting a cultivar with an unsuitable chill requirement is one of the main reasons for lack of fruiting (Hill & Perry, 2011; Martin, 2019).

Question 2: Can I plant just one plum cultivar and expect a crop?

Answer: In most cases – no. Most cultivars are self‑sterile and require cross‑pollination with another cultivar of the same species. Even partially self‑fertile cultivars will give a full crop only with a pollinator present. The only exceptions are a few old, proven self‑fertile cultivars, but they still benefit from neighbours (Hill & Perry, 2011).

Question 3: Do I have to plant a pollinator on my own plot? Could a neighbour’s tree serve?

Answer: Bees can carry pollen up to 100 metres, but for guaranteed pollination the distance between trees should be no more than 20–40 metres (Martin, 2019). If neighbours within that radius have a flowering plum of the same species, it might work. However, for certainty it is better to plant your own pollinator cultivar.

Question 4: How can I tell a European plum from a Japanese plum?

Answer: The main differences are:

• European: Fruits are often oval, flesh firm, stone separates easily. Tree more compact, flowers later. Higher winter hardiness. Requires more chill (Hill & Perry, 2011; Choudhary, 2003).
• Japanese: Fruits are often round or heart‑shaped, flesh juicy, stone adheres. Tree spreading, flowers earlier. Lower winter hardiness. Requires less chill (Hill & Perry, 2011).

Question 5: Which is better: a sapling on a seedling or a clonal rootstock?

Answer: The rootstock is the root system onto which the cultivar is grafted. It determines the vigour and longevity of the tree. In Russian nurseries, seedlings on seedling rootstocks (seedlings of cherry plum, blackthorn, wild plum) are more common. They are well adapted to local conditions and winter‑hardy. Clonal rootstocks (e.g., ‘Druzhba’, ‘VVA‑1’) produce more compact and earlier‑bearing trees but may be less winter‑hardy and more demanding on soil (Potapov, 2000; Trunov, 2012). For an amateur garden in the middle belt, it is better to choose regionally adapted saplings on seedling rootstocks.

Question 6: Can I graft another cultivar onto an old plum tree if I don’t like the chosen one?

Answer: Yes, this is quite feasible. If you have a winter‑hardy tree but its fruit does not satisfy you, you can regraft it (by budding or cleft grafting) onto another, more valuable cultivar. This is called “top‑working”. This method allows you to quickly obtain a crop of a new cultivar on an already established plant. Important: the new cultivar must be compatible with the rootstock (Potapov, 2000).