How to Grow Okitsu Mandarin
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Okitsu Mandarin
Citrus unshiu
treeOkitsu is a seedless mandarin variety originating from Japan, known for its sweet flavor, easy peeling, and prolific fruiting. It is a compact citrus tree that produces abundant fruit without pollination, making it ideal for home gardens. The tree is moderately cold-hardy for a mandarin and has a dense, spreading canopy.
When should you plant Okitsu Mandarin in your zone?
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Example Okitsu Mandarin timeline · Pittsburgh, PA (Zone 6b)
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Plant Okitsu Mandarin
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Okitsu Mandarin
Late summer into fallBefore the first fall frost (≈ Nov 8)
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Growing Conditions
Soil
Growing Zones
Find your zone →Zones 8-10; hardy down to around 12-15°F (-11 to -9°C) with protection
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Get my Okitsu Mandarin timeline →Growth Stages
Establishment (Year 1)
12 monthsYoung tree developing root system and establishing main framework; minimal flowering expected
Water deeply and regularly; apply mulch; stake for wind support; remove early flower buds to redirect energy to growth
Early Fruiting (Years 2-3)
18-24 monthsTree begins producing flowers in spring, developing first commercial-quality fruits
Allow some flowering/fruiting but thin aggressively for larger fruit; maintain balanced fertilization; prune to shape canopy
Flowering & Fruit Development (Spring-Summer)
3-4 monthsFragrant white flowers appear (typically February-March in warm climates); small green fruits form and begin swelling
Thin fruit to 1 per 12 inches of branch to prevent overbearing; maintain consistent watering and fertilizer schedule; monitor for pests
Fruit Maturation (Fall-Winter)
2-3 monthsFruits color from green to orange; sugar content increases; fruit reaches full sweetness
Reduce nitrogen fertilizer; increase potassium and phosphorus; maintain adequate water; fruits ripen on tree
Harvest & Dormancy (Winter)
1-2 monthsFruits ripen fully and are harvested; tree enters semi-dormancy in cooler climates
Harvest when fully colored and slightly soft to touch; prune lightly after harvest; reduce watering in dormant season
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Horticultural oil spray during dormant season or nymphal stage; insecticidal soap; prune heavily infested branches
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Avoid excess nitrogen; remove affected leaves; use sticky traps; beneficial insects (parasitoid wasps) provide natural control
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Neem oil or insecticidal soap spray; horticultural oil; encourage beneficial insects like ladybugs
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Increase humidity; spray with water to dislodge; neem oil; miticide if severe
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Monitor for yellowing leaves; remove infected foliage; avoid moving nursery stock from affected areas; insecticidal soaps
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Spray with strong water stream; insecticidal soap; neem oil; encourage natural predators
Uses
Fresh eating and juice
CulinaryOkitsu mandarins are prized for their exceptional sweetness, thin easy-to-peel skin, and seedless nature. They are perfect for fresh consumption, juicing, and adding to fruit salads or desserts. [source]
Marmalade and preserves
CulinaryThe fruit and peel can be processed into marmalades, jams, and glazes. The thin skin makes them easier to process than thick-skinned varieties. [source]
Ornamental landscaping
HouseholdOkitsu is valued as an attractive ornamental tree with fragrant spring flowers, glossy evergreen foliage, and bright orange winter fruit that extends the garden's visual appeal. [source]
Vitamin C and immune support
MedicinalLike all mandarins, Okitsu is rich in vitamin C and antioxidants, supporting immune function and overall health. A single fruit provides significant daily vitamin C intake. [source]
Aromatherapy from leaves and flowers
HouseholdThe fragrant flowers and aromatic foliage provide natural scent for gardens and can be used in potpourri or dried arrangements. The essential oils have calming properties. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Okitsu mandarins ripen November-January in most climates. Harvest when fully colored and slightly firm to soft; color is the best indicator of ripeness rather than size. Twist or use pruning shears to detach fruit from branch. Fruits will continue to improve in sweetness on the tree; pick at peak color. Handle carefully to avoid bruising.
Fun Facts
- 🌱 Okitsu was developed in Okitsu, Shizuoka Prefecture, Japan in the 1920s and is named after its birthplace. It is one of the most widely planted mandarin varieties in Japan and is sometimes called 'Okitsu Wase' (early Okitsu).
- 🌱 Unlike most citrus, Okitsu is self-fertile and produces abundant seedless fruit without cross-pollination, making it ideal for small yards where space for multiple trees is limited.
- 🌱 Mandarins can bear fruit almost continuously in tropical climates, while in temperate zones Okitsu typically produces one main crop per year (November-January), with occasional off-season flowering.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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