Shiranui Mandarin Tree (Citrus reticulata ‘Shiranui’)

The Shiranui Mandarin tree, also known as the Sumo Citrus®, Dekopon, or Citrus reticulata ‘Shiranui’, is a highly sought-after citrus variety prized for its exceptional flavor and unique appearance. This seedless, easy-to-peel fruit offers a delightful combination of sweetness and tanginess, making it a favorite among citrus enthusiasts. This comprehensive guide will delve into every aspect of the Shiranui Mandarin, from its origins and characteristics to detailed care instructions, purchasing options, and even how to find a Shiranui Mandarin tree for sale near you.

Continue reading to unlock the secrets of successfully growing and enjoying this extraordinary citrus. You’ll find detailed tips on cultivating your own tree, ensuring a bountiful harvest, and even explore opportunities to buy Shiranui Mandarin fruit online.

Understanding the Shiranui Mandarin: Origins, Characteristics, and Appeal

The Shiranui Mandarin’s story begins in Japan in 1972. It’s a hybrid, a carefully crafted cross between a Kiyomi tangor (itself a hybrid of a Miyagawa Wase mikan and a Trovita orange) and a Ponkan (a type of mandarin). Researchers at the Nagasaki Prefectural Fruit Tree Experiment Station aimed to combine the best traits of both parent fruits: the easy-peeling nature and sweetness of the Ponkan with the larger size and juiciness of the Kiyomi. The result was the Dekopon, later trademarked as Sumo Citrus® in the United States.

Common name	Shiranui Mandarin, Sumo Citrus, Dekopon
Botanical name	Citrus reticulata ‘Shiranui’
Family	Rutaceae
Genus	Citrus
Species	reticulata
Origin	Japan
Native	Bred in Japan, cultivated in various suitable climates
Life cycle	Perennial
Plant type	Tree, Fruit Tree, Citrus Tree
Hardiness zone	9, 10, 11 (with potential for zone 8 with protection)
Sunlight	Full Sun (at least 6-8 hours daily; afternoon shade beneficial in very hot climates)
Maintenance	Moderate
Water	Moderate, regular watering; allow soil to slightly dry between waterings
Drainage	Well-Drained (essential to prevent root rot)
Spacing	10-15 ft. apart
Flowering period	Spring
Fruiting Period	Late Winter to Early Spring (typically January – April)
Height	8-15 ft. at maturity (depending on rootstock and pruning)
Growth rate	Moderate
Flower color	White
Fruit color	Bright Orange
Stem color	Green to Brown (as branches mature)
Flower benefit	Fragrant, attracts pollinators
Fruit Benefit	Seedless, Easy to Peel, Exceptional Flavor, High Vitamin C
Garden style	Mediterranean Garden, Edible Garden, Container Garden, Orchard
Uses	Fruit Production, Ornamental Tree, Container Plant
Soil pH	Slightly acidic (6.0-7.5)
Propagation	Grafting (most common), Cuttings (more challenging)
Pest Susceptibility	Aphids, Scale, Citrus Leafminer, Spider Mites (regular monitoring recommended)
Disease Susceptibility	Citrus Greening (HLB), Citrus Canker, Root Rot (prevention through proper care is key)
Special Feature	Distinctive topknot on fruit.

The name “Dekopon” is a combination of “deko” (meaning “uneven” in Japanese, referring to the fruit’s characteristic bump at the stem end) and “pon” from Ponkan. The Sumo Citrus® branding emphasizes the fruit’s substantial size and distinctive topknot, resembling a sumo wrestler’s hairstyle.

Key Characteristics of the Shiranui Mandarin:

Appearance	Large, with a distinctive topknot or bump at the stem end. Bright orange, bumpy skin that is surprisingly easy to peel.
Taste	Intensely sweet with a balanced tartness. Seedless and incredibly juicy. A complex flavor profile often described as “honeyed”.
Texture	Tender, melting flesh with minimal pith. Segments separate easily.
Size	Typically larger than most other mandarin varieties.
Season	Late winter to early spring (generally January to April in the Northern Hemisphere).
Tree Size	Moderate, reaching a height of 8-15 feet at maturity, depending on rootstock and pruning.
Foliage	Evergreen, with glossy, dark green leaves.
Cold Hardiness	Relatively cold-hardy for a citrus, tolerating temperatures down to about 26°F (-3°C) for short periods.

Why is the Shiranui Mandarin So Popular?

Several factors contribute to the Shiranui’s widespread appeal:

• Exceptional Flavor: The combination of sweetness, acidity, and juiciness is unparalleled. It’s often described as a gourmet citrus experience.
• Seedless and Easy to Peel: These qualities make it a convenient and enjoyable snack for people of all ages.
• Unique Appearance: The distinctive topknot and large size make it a visually appealing fruit.
• Limited Availability: The relatively short growing season and specific cultivation requirements contribute to its exclusivity and desirability.
• Health Benifits: Rich Vitamin C, fiber.

Nutritional Value (per approximately 1 medium-sized Shiranui Mandarin – 200g):

Nutrient	Approximate Amount	% Daily Value (DV)
Calories	100-120	5-6%
Carbohydrates	25-30g	8-10%
Sugars	20-25g
Fiber	3-4g	12-16%
Protein	1-2g	2-4%
Fat	<1g	<1%
Vitamin C	100-120mg	110-130%
Potassium	300-350mg	6-7%
Folate	30-40mcg	8-10%
Calcium	30-40mg	2-3%

(Note: These values are approximate and can vary depending on the size and specific growing conditions of the fruit.)

This table offers a clear overview of the nutritional benefits, reinforcing the Shiranui Mandarin’s appeal as a healthy and delicious choice. The high Vitamin C content is particularly noteworthy.

A study published in the Journal of Agricultural and Food Chemistry analyzed the volatile compounds in Dekopon mandarins, revealing a complex profile that contributes to its unique aroma and flavor. These findings further support the fruit’s premium quality and distinguish it from other mandarin varieties. The research provides scientific backing for the sensory experience that consumers enjoy.

Cultivating Your Own Shiranui Mandarin Tree: A Comprehensive Guide

Growing a Shiranui Mandarin tree can be a rewarding experience, providing you with a supply of these delectable fruits. Success depends on understanding the tree’s specific needs and providing the right conditions.

1. Climate and Sunlight:

• Ideal Climate: Shiranui Mandarins thrive in warm, subtropical climates, similar to USDA hardiness zones 9-11. While they can tolerate short periods of cold down to 26°F (-3°C), prolonged freezing temperatures can damage the tree and fruit.
• Sunlight Requirements: Full sun is essential for optimal growth and fruit production. Aim for at least 6-8 hours of direct sunlight per day. In hotter climates, some afternoon shade during the peak summer months may be beneficial to prevent leaf scorch.
• Microclimates: Consider creating a suitable environment, for areas slighly outside ideal zone. South facing area, provide wind protection, near building for radiant heat.

2. Soil and Drainage:

• Soil Type: Well-draining soil is crucial. Shiranui Mandarins prefer slightly acidic soil with a pH of 6.0 to 7.5. Avoid heavy clay soils that retain too much water, as this can lead to root rot.
• Improving Drainage: If your soil is heavy, amend it with organic matter like compost, perlite, or coarse sand to improve drainage. Raised beds or containers are also excellent options for ensuring proper drainage.
• Soil Testing: Before planting, it’s recommended to conduct a soil test to determine its pH and nutrient levels. This will help you identify any deficiencies and amend the soil accordingly.

3. Planting Your Shiranui Mandarin Tree:

• Choosing a Tree: Select a healthy tree from a reputable nursery. Look for a tree with strong, well-developed branches and no signs of disease or pests. Consider buying a grafted tree, as this will ensure earlier fruiting and better disease resistance.
• Planting Time: The best time to plant a Shiranui Mandarin tree is in the spring after the last frost, or in the early fall in milder climates.
• Planting Procedure:
  1. Dig a hole twice as wide as the root ball and just as deep.
  2. Gently remove the tree from its container, being careful not to damage the roots.
  3. Loosen any circling roots around the root ball.
  4. Place the tree in the hole, ensuring that the top of the root ball is level with the surrounding ground.
  5. Backfill the hole with soil, gently firming it around the roots.
  6. Water the tree thoroughly after planting.
• Spacing: If planting multiple Shiranui, allow approximately 10-15 feet of space.

4. Watering and Fertilizing:

• Watering: Shiranui Mandarins require regular watering, especially during dry periods. Water deeply and thoroughly, allowing the soil to dry slightly between waterings. Avoid overwatering, as this can lead to root rot. The frequency of watering will depend on your climate, soil type, and the age of the tree. Young trees require more frequent watering than mature trees.
• Fertilizing: Citrus trees are heavy feeders and require regular fertilization. Use a citrus-specific fertilizer that contains micronutrients like iron, zinc, and manganese. Follow the manufacturer’s instructions for application rates and timing. Generally, fertilize young trees every 2-3 months during the growing season (spring and summer) and reduce fertilization in the fall and winter. Mature trees can be fertilized 3-4 times per year.
• Mulching: Apply a layer of organic mulch, such as wood chips or bark, around the base of the tree. This helps retain moisture, suppress weeds, and regulate soil temperature. Keep the mulch a few inches away from the trunk to prevent rot.

5. Pruning and Training:

• Pruning: Pruning is essential for maintaining the shape and health of your Shiranui Mandarin tree. Prune to remove dead, damaged, or crossing branches. You can also prune to shape the tree and encourage fruit production. The best time to prune is in late winter or early spring, before new growth begins.
• Training: Young trees may benefit from training to establish a strong framework. This can involve staking the tree to support its growth and selectively pruning branches to encourage a desired shape.

6. Pest and Disease Management:

• Common Pests: Shiranui Mandarins can be susceptible to various pests, including aphids, scale insects, citrus leafminers, and spider mites. Regularly inspect your tree for signs of pests and take action if necessary.
• Pest Control: Use organic pest control methods whenever possible, such as insecticidal soap, neem oil, or horticultural oil. For severe infestations, you may need to use a stronger insecticide.
• Common Diseases: Citrus trees can be affected by diseases such as citrus greening (Huanglongbing or HLB), citrus canker, and root rot. Prevention is key. Choose disease-resistant rootstock, ensure proper drainage, and avoid overwatering.
• Disease Management: If you suspect a disease, consult with your local agricultural extension office or a certified arborist for diagnosis and treatment recommendations.

7. Harvesting Your Shiranui Mandarins:

• Ripening: Shiranui Mandarins typically ripen from late winter to early spring. The fruit will turn a deep orange color and develop its characteristic topknot.
• Harvesting Technique: Gently twist or clip the fruit from the tree, being careful not to damage the branches. Handle the fruit carefully, as it can bruise easily.
• Storage: Shiranui Mandarins can be stored at room temperature for a week or two, or in the refrigerator for several weeks.

Purchasing Shiranui Mandarin Trees and Fruit: Options and Considerations

Whether you’re looking to buy a tree to cultivate your own fruit or simply want to enjoy the delicious taste of Shiranui Mandarins, there are several options available.

1. Buying Shiranui Mandarin Trees:

• Local Nurseries: This is often the best option, especially if you’re looking for a tree that’s adapted to your local climate. Local nurseries can also provide expert advice on planting and care. Search online for “Shiranui Mandarin tree for sale near me” or “citrus tree nursery [your city/state]” to find local options. Gardencenterpoint.com can help you locate reputable nurseries in your area.
• Online Retailers: Several online nurseries specialize in citrus trees, including Shiranui Mandarins. This can be a convenient option if you don’t have access to a local nursery that carries them. Be sure to choose a reputable retailer with good reviews and a guarantee on their trees.
• Things to Consider When Buying a Tree:
  • Tree Size: Choose a tree size that’s appropriate for your space.
  • Rootstock: Consider the rootstock, as it can affect the tree’s size, cold hardiness, and disease resistance.
  • Tree Health: Inspect the tree carefully for signs of pests or diseases.
  • Shipping: If ordering online, inquire about shipping costs and policies.

2. Buying Shiranui Mandarin Fruit (Sumo Citrus®):

• Grocery Stores: During the season (typically January to April), Shiranui Mandarins (often labeled as Sumo Citrus®) are increasingly available in major grocery stores and specialty produce markets.
• Online Retailers: Several online retailers specialize in delivering fresh produce, including Shiranui Mandarins. This can be a convenient option if you can’t find them locally.
• Farmers Markets: Local farmers markets may offer Shiranui Mandarins during the season, providing an opportunity to support local growers.
• Price consideration: Prices can vary depending on several factors, including location, retailer, and time of year.

Example Pricing (as of 2024/2025, subject to change):

Grocery Stores	$3-$5 per pound	Prices may vary depending on location and retailer.
Online Retailers	$4-$7 per pound (plus S&H)	Shipping costs can add significantly to the overall price.
Farmers Markets	$3-$6 per pound	Prices may be slightly higher, but you’re supporting local growers.
Local Nurseries(Tree)	$30-80+ (tree)	Price depends on the tree size, rootstock.

Common Shiranui Mandarin Tree Problems

Even with the best care, you may encounter some challenges when growing a Shiranui Mandarin tree. Here are some common problems and their solutions:

• Yellowing Leaves: This can be caused by several factors, including nutrient deficiencies (especially iron), overwatering, underwatering, or pest infestations. Conduct a soil test to determine if nutrient deficiencies are the issue. Adjust your watering schedule as needed. Inspect the leaves for pests and treat accordingly.
• Leaf Drop: Some leaf drop is normal, especially during seasonal changes. However, excessive leaf drop can indicate stress from factors like temperature fluctuations, drought, overwatering, or disease. Identify the underlying cause and address it.
• Fruit Drop: Premature fruit drop can be caused by stress factors, such as inconsistent watering, nutrient deficiencies, or pest infestations. Ensure consistent watering, fertilize regularly, and manage pests.
• Lack of Fruit Production: If your tree is not producing fruit, it may be due to several factors:
  • Age: Young trees may not produce fruit for the first few years.
  • Lack of Sunlight: Ensure your tree receives at least 6-8 hours of direct sunlight per day.
  • Poor Pollination: While Shiranui Mandarins are self-fertile, cross-pollination with another citrus variety can sometimes improve fruit set.
  • Nutrient Deficiencies: Conduct a soil test and fertilize accordingly.
  • Improper Pruning: Avoid excessive pruning, as this can remove flower buds.
• Pest Infestations: As mentioned earlier, aphids, scale insects, citrus leafminers, and spider mites can affect Shiranui Mandarins. Regularly inspect your tree and take action if necessary, using organic pest control methods whenever possible.
• Sunburn: Sunburn can occur in areas with intense sunlight. Provide a shade cloth if necessary.

Advanced Tips for Shiranui Mandarin Success

• Rootstock Selection: The rootstock on which your Shiranui Mandarin is grafted can significantly impact its growth, fruit production, and disease resistance. Some common rootstocks for citrus include:
  • C-35 Citrange: A popular rootstock that offers good cold hardiness, disease resistance, and dwarfing characteristics.
  • Carrizo Citrange: Another popular choice with good disease resistance and compatibility with various citrus varieties.
  • Trifoliate Orange: Known for its excellent cold hardiness, but can be more susceptible to certain soil conditions.
  • Discuss rootstock options with your nursery to determine the best choice for your specific needs and climate.
• Microclimate Management: Even if your overall climate isn’t ideal for citrus, you can create microclimates within your yard to improve growing conditions. Planting your tree near a south-facing wall, for example, can provide radiant heat and protection from wind.
• Companion Planting: Certain plants can benefit citrus trees by attracting beneficial insects, repelling pests, or improving soil health. Consider planting companion plants like:
  • Marigolds: Repel nematodes and other soilborne pests.
  • Nasturtiums: Attract aphids away from the citrus tree (trap crop).
  • Legumes (clover, beans): Fix nitrogen in the soil, providing a natural fertilizer.
• Winter Protection: In areas with occasional frosts, protect your Shiranui Mandarin tree by:
  • Watering deeply before a freeze: Moist soil retains heat better than dry soil.
  • Covering the tree with a frost blanket or burlap: This can provide several degrees of protection.
  • Using Christmas lights (incandescent, not LED) to provide warmth: String the lights around the branches of the tree.
• Soil Amendments: Regularly amend your soil with organic matter to improve drainage, fertility, and water retention. Compost, aged manure, and worm castings are excellent choices.