Chinese Juniper / Shimpaku
Juniperus chinensis · Shimpaku (真柏)
The undisputed monarch of conifer bonsai. Celebrated for its tight scale foliage, dramatic carved deadwood (jin and shari), and incredible hardiness, Shimpaku junipers (particularly the Kishu and Itoigawa cultivars) are the cornerstone of classic exhibition displays.
Substrate & Soil Mix
60% Akadama, 20% Pumice, 20% Volcanic Lava (sharp drainage essential).
Watering Discipline
Moderate; let surface substrate dry slightly between thorough soakings.
Sunlight & Placement
Full sun year-round. Shade causes interior foliage to brown and die back.
Pruning & Pinching Window
Late spring through mid-summer via finger-pinching (never scissors on needle tips).
Wiring Season
Late autumn through winter during sap dormancy.
Repotting Cadence
Every 2–3 years for young specimens; 4–6 years for mature trees in early spring.
Curatorial Cultivation Manual
Irrigation Technique
Junipers thrive on regular misting of foliage and deep watering when the soil surface dries. Avoid keeping the rootball waterlogged, which promotes Phytophthora root rot.
Seasonal Fertilizing Program
Apply organic slow-release fertilizer cakes (e.g. Bio-Gold or 5-5-5) from bud-burst through late autumn. Cease nitrogen feeding during the peak heat of midsummer.
Pruning & Pad Refinement
Pinch vigorous terminal shoots with your fingers to preserve compact pads. Scissors will oxidize and brown cut needle tips. Deadwood carving is best executed in autumn.
Root Reduction & Repotting
Repot in early spring just as root tips show active green growth. Never wash the entire rootball; preserve native mycorrhizal fungi.
Winter Cold Protection
Extremely frost-hardy down to -15°C (5°F). In colder climates, shield the pot from desiccating freezing winds in a cold frame or unheated garage.
Common Pests & Pathogens
- Spider mites
- Juniper scale
- Fungal tip blight
- Cedar-apple rust
Traditional Classical Styles
- Informal Upright (Moyogi)
- Cascade (Kengai)
- Literati (Bunjin)
- Windswept (Fukinagashi)
- Raft (Ikadabuki)
Document Your Chinese Juniper / Shimpaku in Kenara
Log repotting histories, track seasonal wiring timelines, and run optical foliage health diagnostics on your trees.