Korean Mountain Ash Sorbus commixta
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The plant known as Sorbus commixta, commonly referred to as the Japanese rowan, exhibits a head-turning display of features throughout the seasons. Characteristically, it bears compound leaves, which are made up of several smaller, oval-shaped leaflets arranged on a central stem, much like the outstretched fingers on a hand. These leaflets have serrated edges, giving the foliage an intricate and textured appearance. In the spring, the Japanese rowan dazzles with clusters of delicate white flowers, each cluster akin to a small, frothy bouquet. These attractive flowers not only add ornamental value but also attract a variety of pollinators to the garden. As the season progresses to autumn, the foliage undergoes a spectacular transformation. The leaves take on a fiery array of colors, exhibiting a tapestry of reds, oranges, and yellows that signal the changing seasons. This vibrant autumnal display is one of its most noteworthy features, providing a striking backdrop against the cooler days. Following the floral display, the Japanese rowan produces berries that are typically bright red or sometimes orange. These berries are small and spherical, like little baubles adorning the branches. They remain on the tree well into the winter months, providing visual interest as well as a food source for birds and other wildlife when other resources are scarce. The overall form of the Japanese rowan is pleasing to the eye, with branches that create an attractive, rounded silhouette. The bark of this plant is another point of interest with a textured surface that adds to its ornamental appeal. The interplay of the striking foliage, showy flowers, colorful berries, and distinctive bark makes the Japanese rowan a sought-after plant for gardeners seeking year-round interest.
About this plant
NamesSynonyms
Korean Mountain Ash, Japanese Rowan
Common names
Pyrus commixta, Sorbus commixta var. sachalinensis, Sorbus sachalinensis
ToxicityTo humans
The Korean mountain ash (Sorbus commixta) is not generally known for being toxic to humans. However, as with many plants, the seeds contain small amounts of cyanogenic glycosides which can release cyanide when digested. Consuming large quantities of seeds could potentially lead to symptoms such as nausea, headache, dizziness, and in severe cases, difficulty breathing and decreased heart rate due to the cyanide inhibiting the body's ability to use oxygen. These occurrences are rare as one would have to consume a very large quantity of seeds for poisoning to occur.
To pets
Korean mountain ash is not typically toxic to pets. The seeds, like in the case with humans, contain cyanogenic glycosides, which can be toxic in large quantities. However, it is unlikely for a pet to consume enough of the seeds to cause cyanide poisoning. Symptoms of cyanide poisoning in pets can include vomiting, diarrhea, difficulty breathing, and lethargy. If you suspect your pet has consumed a large amount of seeds and is showing these symptoms, it is important to contact a veterinarian.
CharacteristicsLife cycle
Perennials
Foliage type
Deciduous
Color of leaves
Green
Flower color
White
Height
15-30 feet (4.5-9 meters)
Spread
15-25 feet (4.5-7.6 meters)
Plant type
Tree
Hardiness zones
5-7
Native area
Asia
Benefits
General Benefits- Aesthetic Appeal: Sorbus commixta, commonly known as the Korean mountain ash, features showy autumn colors and is often used for ornamental purposes in landscaping.
- Wildlife Attraction: The tree produces berries that are a food source for various species of birds and mammals, supporting local biodiversity.
- Shade Provider: With its broad canopy, it provides shade in gardens and parks, making it valuable for creating cool, shaded areas in landscaped environments.
- Erosion Control: Its extensive root system helps stabilize the soil and prevent erosion on slopes and in areas at risk of soil loss.
- Adaptive Growth: Korean mountain ash can adapt to various soil conditions and climates, making it a robust and versatile choice for many regions.
- Seasonal Interest: It offers a year-round interest with blossoms in spring, fruit in summer, vivid foliage in the fall, and a stark silhouette in the winter.
- Habitat Creation: The tree can form part of a habitat garden, offering refuge and nesting sites for birds and other wildlife.
Medical Properties- Astringent: The bark or fruit of Sorbus commixta is said to have astringent properties, which can help to tighten and tone the skin and mucous membranes.
- Antioxidant: This plant has antioxidants that may help in protecting cells from damage caused by free radicals.
- Diuretic: Sorbus commixta may promote increased urine production, which can help in flushing out toxins from the body.
- Liver function support: There is some indication that the plant may support liver health, but concrete evidence is limited and further research is needed.
Air-purifying QualitiesThis plant is not specifically known for air purifying qualities.
Other Uses- Sorbus commixta, commonly known as the Japanese rowan, can be used as a natural dye, providing a range of colors from its bark, leaves, and berries depending on the mordant used.
- The wood of the Japanese rowan is hard and dense, making it suitable for crafting durable wooden tools and handles.
- The berries of Japanese rowan can be fermented to make alcoholic beverages such as wine or liqueur, offering a unique flavor.
- In woodworking, the attractive grain of Japanese rowan wood can be used for veneers and inlays in fine furniture making.
- The Japanese rowan is often used in bonsai practice, appreciated for its elegant branching patterns and colorful autumn foliage.
- Traditional crafts such as basket weaving can utilize the flexible young shoots of the Japanese rowan.
- The Japanese rowan can be planted as a companion plant in gardens; its dense root system may help stabilize soil and prevent erosion.
- The tree's bright red or orange berries provide food for birds during the winter, thus supporting local wildlife and biodiversity.
- Japanese rowan can be used in urban landscaping as it is relatively tolerant to pollution and can help in greening city environments.
- The leaves of Japanese rowan can be used to create leaf mold, a type of compost that is particularly good for improving soil structure and water retention.
Interesting Facts
Feng ShuiThe Mountain Ash is not used in Feng Shui practice.
Zodiac Sign CompitabilityThe Mountain Ash is not used in astrology practice.
Plant Symbolism- Resilience - Sorbus commixta, commonly known as the Korean Mountain Ash, is known for its resilience as it can thrive in harsh, cold environments, symbolizing the ability to endure difficult conditions.
- Protection - In some cultures, trees similar to the Korean Mountain Ash are considered protective, as their dense canopies and sturdy structure are thought to guard against negative influences.
- Beauty in Change - The Korean Mountain Ash is renowned for its vibrant autumn foliage, symbolizing the beauty and positivity found in change and transformation.
- Renewal - As a deciduous tree that sheds its leaves in the fall and grows new ones in the spring, it represents the cycle of renewal and the idea of new beginnings.
WaterThe Korean Mountain Ash (Sorbus commixta) should be watered deeply to ensure moisture reaches the root zone, typically requiring about 1 to 2 gallons of water per week during active growth in spring and summer. Reduce watering in the fall to once every two to three weeks, with the equivalent of 1 gallon per session, as the plant begins to enter dormancy. During winter, watering can be further reduced, and the tree may only need water every few weeks if there is no significant rainfall. Ensure the soil is well-draining to prevent waterlogging, and always check the top couple of inches of soil for dryness before watering again.
LightThe Korean Mountain Ash prefers full sun to partial shade, meaning it should receive at least 4 to 6 hours of direct sunlight daily. Ideally, plant it in a location where it can enjoy morning sunshine and some afternoon shade, particularly in hotter climates, to protect it from the intense midday sun.
TemperatureThe Korean Mountain Ash can survive in a temperature range from around -20°F to 100°F, with its ideal growth temperatures being between 60°F and 80°F. It is a hardy tree that can tolerate cold winters, making it suitable for many temperate climates where extreme heat does not persist for long periods.
PruningPrune the Korean Mountain Ash to remove dead or diseased branches, improve its shape, and encourage healthy growth. Pruning is best done in late winter to early spring before new growth begins. Thinning out overcrowded branches every two to three years allows light and air to penetrate the canopy and can prevent disease.
CleaningAs needed
SoilThe Japanese Rowan prefers well-draining soil mixed with organic matter, like compost or peat moss. A slightly acidic to neutral pH ranging from 5.5 to 7.0 is ideal. For optimal growth, use a soil mixture that can retain moisture without becoming waterlogged.
RepottingJapanese Rowans are trees and generally do not require frequent repotting once planted in the ground. If grown in a container, repotting every 2-3 years or when rootbound is beneficial for its growth.
Humidity & MistingJapanese Rowan trees are adaptable to a wide range of humidity levels but prefer average to high humidity conditions. No specific humidity level is necessary, making it suitable for most outdoor environments.
Suitable locationsIndoor
Ensure bright light, cool temps, and space for growth.
Outdoor
Plant in well-drained soil, full sun to partial shade.
Hardiness zone
5-8 USDA
Life cycleSorbus commixta, commonly known as the Korean Mountain Ash, undergoes a typical angiosperm life cycle that includes seed germination, juvenile phase, maturity, flowering, pollination, fruiting, and seed dispersal stages. After germination, the seedling develops roots, a stem, and the first leaves, entering the juvenile phase which can last several years before the tree reaches maturity. Once mature, the Korean Mountain Ash produces creamy-white flowers in the spring or early summer that are pollinated by insects. Following successful pollination, ovules develop into seeds within small, reddish-orange pomes (fruits) that mature by late summer or autumn. Birds and other wildlife often eat these fruits, aiding in the dispersal of the seeds, which can subsequently lead to the establishment of new plants if the seeds find suitable conditions to germinate and grow. The tree continues to go through these flowering and fruiting cycles annually until it reaches the end of its lifespan, which can be several decades long.
PropogationPropogation time
Late Winter
Propogation: The most popular method of propagation for Sorbus commixta, commonly known as Japanese rowan, is through seed sowing. Seeds should be collected in the fall once the berries have ripened and should undergo a process called cold stratification to break seed dormancy; this typically involves mixing the seeds with moist sand and storing them in the refrigerator (around 33-40 degrees Fahrenheit or 1-4 degrees Celsius) for 2-3 months. After stratification, seeds can be sown in containers with a well-draining soil mix either in a cold frame or in a sheltered outdoor spot in the spring. Germination can be slow and irregular, but the emerging seedlings require careful attention to watering and protection from extreme weather until they are strong enough to be transplanted to their final location in the garden or landscape.
