Plum Blossom (Prunus mume)

Plum Blossom, Japanese Apricot, Japanese Flowering Apricot, Japanese Flowering Plum, Mei, Mume

The blooms of Japanese apricot are the sign of an upcoming spring in China. They bloom in late winter on bare branches, often appearing under a blanket of snow. The tree has an important cultural significance in East Asia, while its sweet, edible fruit has various culinary uses. Many varieties of Prunus mume are cultivated worldwide as ornamental trees.

I. Appearance and Characteristics 

Prunus mume is a Chinese tree species classified in the Armeniaca section of the genus Prunus subgenus Prunus. Its common names include Chinese plum, Japanese plum, and Japanese apricot. The flower, long a beloved subject in the traditional painting and poetry of Sinospheric countries (including China, Korea, Vietnam, and Japan), is usually called plum blossom. This distinct tree species is related to both the plum and apricot trees. Although generally referred to as a plum in English, it is more closely related to the apricot. In East Asian cuisine (Chinese, Japanese, Korean and Vietnamese cuisine), the fruit of the tree is used in juices, as a flavouring for alcohol, as a pickle, and in sauces. It is also used in traditional medicine.

The tree’s flowering in late winter and early spring is highly regarded as a seasonal symbol.

Prunus mume should not be confused with Prunus salicina, a related species also grown in China, Japan, Korea, and Vietnam. Another tree, Prunus japonica, is also a separate species despite having a Latin name similar to Prunus mume’s common name.

Prunus mume originated around the Yangtze River in the south of China. It was later introduced to Japan, Korea, and Vietnam. It can be found in sparse forests, stream sides, forested slopes along trails, and mountains, sometimes at altitudes up to 1,700–3,100 m (5,600–10,200 ft), and regions of cultivation.

Prunus mume is a deciduous tree that starts to flower in mid-winter, typically around January until late February in East Asia. It can grow to 4–10 m (13–33 ft) tall. The flowers are 2–2.5 cm (0.79–0.98 in) in diameter and have a strong fragrant scent. They have colors in varying shades of white, pink, and red. The leaves appear shortly after the petals fall, are oval-shaped with a pointed tip, and are 4–8 cm long and 2.5–5 cm wide. The fruit ripens in early summer, around June and July in East Asia, and coincides with the East Asian rainy season, the meiyu (梅雨, “plum rain”). The drupe is 2–3 cm (0.79–1.18 in) in diameter with a groove running from the stalk to the tip. The skin turns yellow, sometimes with a red blush, as it ripens, and the flesh becomes yellow. The tree is cultivated for its fruit and flowers.

II. How to Grow and Care

Sunlight

Like most flowering and fruiting trees, plum blossom trees will do best in a location that receives full sun. However, the tree can grow in partial shade conditions but it should receive at least four hours of sunlight a day.

Temperature and Humidity

The ideal climate for plum blossom trees is USDA hardiness zones 6 to 8, which can see temperatures dip below 0°F. Trees planted in the coldest regions should be located in a sheltered area to protect against the effects of harsh winter winds.

On the other hand, if you grow plum blossom trees in a warmer climate, choose a planting location that provides partial shade during the hottest part of the day to avoid foliage damage from intense sun.

Watering

You should water Japanese apricot and adjust the frequency of watering based on its stage of growth, the local weather, and the condition of the soil. Before budding (in mid-spring), it should be watered once. From mid-spring to just before the fall, it should be watered every month. It needs to be thoroughly watered each time you water it, until the water on the soil surface stops draining away. This will ensure that it has sufficient water for growth.

After watering, remember to loosen the soil and remove any weeds in a timely fashion. Stop watering in the autumn and especially in the winter, otherwise it will suffer from frost damage.

Soil

Well-draining soil is the main requirement for the planting site. And while the tree can tolerate a range of soil conditions, loamy, rich soil is ideal. It prefers acidic soil pH levels. 

Fertilizing

Japanese apricot likes to be fertilized. A sufficient amount of fertilizer will ensure that it grows healthily and bears fruit. Organic fertilizer is usually used for its base fertilizer. When applying fertilizer, dig a circular trench around the external circumference of the tree crown, at a depth of 38 cm and a width of 28 cm. Apply the fertilizer evenly throughout the trench, then backfill the soil.

Fertilizer should be applied twice a year, the first time prior to blooming, to supply nutrients for the flowers, and the second time when the fruit is growing larger, to supply nutrients for fruit growth and to increase the yield.

Planting Instructions

You can purchase Japanese apricot seedlings in garden centers. Pay attention to two things before planting. First, choose an area of the garden that has a lower altitude to plant your Japanese apricot. This will help it to acquire enough water because its roots are shallow. Additionally, apply sufficient base fertilizer before planting it, mostly organic fertilizer. Once planted, remember to water it soon after, until the water on the surface of the soil stops draining away. When this happens you have provided sufficient water.

We generally do not sow seeds to propagate Japanese apricot because the seeds need to undergo post-ripening effects. This means that the seeds are not yet mature when they are harvested. It is only after a period of special treatment that the seeds can complete their biochemical processes and reach the condition of being mature seeds that are able to germinate.

Pruning

Japanese apricot sprouts on branches that have strong budding capabilities. However, the branches can easily become overcrowded and need frequent pruning to maintain the shape, air circulation, and light exposure within the tree. This also helps to prevent pests and diseases while at the same time helping the leaves receive more sunlight.

Japanese apricot can generate a large amount of fruit without any artificial pollination. Because japanese apricot can produce a large number of flowers with a high yield of fruit, to maintain its growth and the quality of fruit, it is recommended that some flowers and fruit be removed to concentrate the nutrients for the remaining fruit. As a result, there will not be a large amount of fruit, but those left will be of higher quality and have an improved flavor.

Propagation

Cut a T-shaped opening in the stock, and insert the branch or bud into the cut between its xylem and phloem, while making sure the phloem vessels are in contact with each other. Then, use plastic wrapping to bind them together. After 10-20 days, when the cut has healed and the branch or bud has survived, the plastic wrap can be removed.

Pests and Diseases

Common Pests & Plant Diseases 

Some of the most common pests that are attracted to plum blossom trees are aphids, spider mites, tent caterpillars, and borers. Scale can also be a problem, especially on the fruit produced by the tree.

Diseases that sometimes afflict plum blossom trees are usually fungal. Some of the most common infections are honey fungus, verticillium wilt, silver leaf, and brown rot. In addition, Prunus species are also subject to bacterial canker, which causes sunken, oozing sections of bark and impedes shoot development.

Common Problems 

Plum blossom trees are generally considered to be low-maintenance but they can be impacted by various pests or environmental conditions. The most common issue relates to imbalances in watering or infection from bacteria and fungi.

Leaves Turning Yellow or Brown

If the leaves of the plum blossom tree begin to turn yellow, it could be a sign that the tree is experiencing stress from being under-watered. Check the soil and ensure that it’s moist. Water regularly to improve soil moisture but don’t overwater the tree, remembering that the soil shouldn’t become overly saturated and that it can take time for a tree to recover from drought stress. 

Leaves that turn yellow or develop brown spots can also be a sign of fungal or bacterial infection. A closer inspection of the tree’s limbs and roots can reveal other symptoms that might point to verticillium wilt, bacterial canker, brown rot, or silver leaf disease. If you suspect any of these diseases, it would be best to do more research on the specific condition and how to minimize the impact of the disease on your tree and surrounding landscape plants.

III. Uses and Benefits 

Culinary use

  • Beverage

In China, suanmeitang (酸梅湯; “sour plum juice”) is made from smoked plums, called wumei (烏梅). The plum juice is extracted by boiling smoked plums in water and sweetened with sugar to make suanmeitang. It ranges from light pinkish-orange to purplish black in colour and often has a smoky and slightly salty taste. It is traditionally flavoured with sweet osmanthus flowers, and is enjoyed chilled, usually in summer.

In Korea, both the flowers and the fruits are used to make tea. Maehwa-cha (매화차, 梅花茶; “plum blossom tea”) is made by infusing the flowers in hot water. Maesil-cha (매실차, 梅實茶; “plum tea”) is made by mixing water with maesil-cheong (plum syrup) and is served either hot or cold.

In Japan, a similar drink is made from green plums and tastes sweet and tangy, is considered a cold, refreshing drink, and is often enjoyed in the summer.

  • Condiment

A thick, sweet Chinese sauce called meijiang (梅醬) or meizijiang (梅子醬), usually translated as “plum sauce”, is also made from the plums, along with other ingredients such as sugar, vinegar, salt, ginger, chili, and garlic. Similar to duck sauce, it is used as a condiment for various Chinese dishes, including poultry dishes and egg rolls.

In Korea, maesil-cheong (매실청, 梅實淸, “plum syrup”), an anti-microbial syrup made by sugaring ripe plums, is used as a condiment and sugar substitute. It can be made by simply mixing plums and sugar together, and then leaving them for about 100 days. To make syrup, the ratio of sugar to plum should be at least 1:1 to prevent fermentation, by which the liquid may turn into plum wine. The plums can be removed after 100 days, and the syrup can be consumed right away, or mature for a year or more.

  • Flower pancake

In Korea, hwajeon (화전, 花煎; “flower pancake”) can be made with plum blossoms. Called maehwa-jeon (매화전, 梅花煎; “plum blossom pancake”), the pancake dish is usually sweet, with honey as an ingredient.

  • Liquor

Plum liquor, also known as plum wine, is popular in both Japan and Korea, and is also produced in China. Umeshu (梅酒; “plum wine”) is a Japanese alcoholic drink made by steeping green plums in shōchū (clear liquor). It is sweet and smooth. A similar liquor in Korea, called maesil-ju (매실주, 梅實酒; “plum wine”), is marketed under various brand names, including Mae hwa soo, Matchsoon, and Seoljungmae. Both the Japanese and Korean varieties of plum liquor are available with whole plum fruits contained in the bottle. In China, plum wine is called méijiǔ (梅酒).

In Taiwan, a popular 1950s innovation over the Japanese-style plum wine is the wumeijiu (烏梅酒; “smoked plum liquor”), which is made by mixing two types of plum liquor, meijiu (梅酒) made of P. mume and lijiu (李酒), made of P. salicina, and oolong tea liquor.

In Vietnam, ripe plums are macerated in sticky rice liquor. The resulting liquor is called rượu mơ. A brand selling plum liquor is Sơn Tinh.

  • Pickled and preserved plums

In Chinese cuisine, plums pickled with vinegar and salt are called suanmeizi (酸梅子; “sour plum fruits”), and have an intensely sour and salty flavor. They are generally made from unripe plum fruits. Huamei (話梅) are Chinese preserved plums and refer to Chinese plums pickled in sugar, salt, and herbs. There are two general varieties: a dried variety, and a wet (pickled) variety.

Umeboshi (梅干) are pickled and dried plums. They are a Japanese specialty. Pickled with coarse salt, they are quite salty and sour, and therefore eaten sparingly. They are often red in color when purple shiso leaves are used. Plums used for making umeboshi are harvested in late May or early June, while they are ripe enough in yellow, and layered with much salt. They are weighed down with a heavy stone (or some more modern implement) until late August. They are then dried in the sun on bamboo mats for several days (they are returned to the salt at night). The flavonoid pigment in shiso leaves gives them their distinctive colour and a richer flavor. Umeboshi are generally eaten with rice as part of a bento (boxed lunch), although they may also be used in makizushi (rolled sushi). Umeboshi are also used as a popular filling for rice balls (onigiri) wrapped in nori. Makizushi made with plums may be made with either umeboshi or bainiku (umeboshi paste), often in conjunction with green shiso leaves. A byproduct of umeboshi production is umeboshi vinegar, a salty, sour condiment.

In Korea, there is ‘maesil-jangajji’ which is similar to ‘Umeboshi’. It is a common side dish in Korea.

A very similar variety of pickled plum, xí muội or ô mai is used in Vietnamese cuisine. The best fruit for this are from the forest around the Hương Pagoda in Hà Tây Province.

Medicinal uses

Prunus mume is a common fruit in Asia and is used in traditional Chinese medicine.

IV. Harvesting and Storage

The fruits of japanese apricot usually ripen in the early fall and can be picked for eating. If the fruit needs to be stored or transported a long distance, it is better to harvest the fruit before it softens, such as during the late summer or early fall. Note that fruit should be handled gently and, ideally, and the twig should remain on the fruit.

Plum Blossom (Prunus mume) Details

Common name Plum Blossom, Japanese Apricot, Japanese Flowering Apricot, Japanese Flowering Plum, Mei, Mume
Botanical name Prunus mume
Plant type Tree
Hardiness zone 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
Growth rate Fast
Harvest time Summer
Height 15 ft. 0 in. - 20 ft. 0 in.
Width 15 ft. 0 in. - 20 ft. 0 in.
Sunlight Full sun (6 or more hours of direct sunlight a day)
Soil condition High Organic Matter
Flower color Pink
Leaf color Green