Acer palmatum
Japanese Maple
Highly refined deciduous tree; delicate branching and strong seasonal appeal; widely used in bonsai.
DeciduousBroadleaf
Now: Mid Spring
- watering
- Maintain even moisture; soil warms—might need daily watering in pots.
- fertilization
- Feed every 2–3 weeks with balanced bonsai fertilizer.
- bud shoot management
- Trim long shoots after first flush to promote ramification.
- pests disease
- Monitor for caterpillars and scale insects.
Care Guide
Placement
Partial shade to full sun
Protect from hot afternoon sun to avoid leaf burn.
Watering
High
Never allow to dry out completely.
Fertilization
Balanced
Avoid high-nitrogen after midsummer.
Pruning
Structural in early spring, maintenance through summer
Pinch new shoots to maintain shape.
Wiring
Spring or Autumn
Use guy wires for older wood to reduce scarring.
Repotting
Every 2-3 years
Repot just as buds begin to swell.
Propagation
Cuttings or seed
Cuttings root easily with hormone.
Winter: Protect fine branches from late frost.
Summer: Mist foliage to counteract dry air.
Zone 8b: Protect roots if temps < 20 F
Seasonal Calendar
Late Dormancy02-15 — 03-10
- watering
- Keep soil lightly moist to prevent desiccation during root activation.
- pruning
- Perform final structural cuts before bud swell; avoid heavy pruning.
- wiring
- Safe to wire before buds open, but wood is brittle—use caution.
- pests disease
- Clear debris to reduce overwintering pests.
- winter protection
- Provide root insulation; watch for late freezes.
- wound management
- Seal larger pruning cuts to reduce cold damage.
Early Spring03-11 — 04-15
- watering
- Gradually increase; encourage steady moisture as buds swell.
- fertilization
- Begin light feeding with balanced 10‑10‑10 formula post-leafing.
- repotting
- Repot window opens just before leaf burst; root prune carefully.
- pruning
- Trim new buds lightly to refine structure.
- wiring
- Apply or adjust wiring while cambium is active.
- bud shoot management
- Pinch long shoots to encourage back-budding.
- pests disease
- Scout for aphids; treat organically if seen.
- propagation
- Softwood cuttings may be rooted at this time.
- development
- Allow trunk base to thicken by limiting aggressive top pruning.
Mid Spring04-16 — 05-10Now
- watering
- Maintain even moisture; soil warms—might need daily watering in pots.
- fertilization
- Feed every 2–3 weeks with balanced bonsai fertilizer.
- bud shoot management
- Trim long shoots after first flush to promote ramification.
- pests disease
- Monitor for caterpillars and scale insects.
Late Spring05-11 — 05-31
- watering
- Increase frequency based on warming temperatures.
- fertilization
- Switch to higher nitrogen (e.g., 12‑6‑6) if tree is vigorous.
- pests disease
- Leaf-chewing pests may emerge—treat promptly.
Early Summer06-01 — 06-30
- watering
- Deep water regularly—pots warm up quickly in heat.
- fertilization
- Continue balanced feed every 2 weeks.
- pruning
- If leaf size becomes excessive, consider partial defoliation.
- wiring
- Minor wiring for refinement before tissue hardens.
- defoliation
- Partial defoliation after first flush can reduce leaf size.
- pests disease
- Watch for mites; treat with horticultural oil if needed.
- summer protection
- Provide afternoon shade during heatwaves.
Mid Summer07-01 — 08-10
- watering
- Monitor daily; ensure no drought stress.
- fertilization
- Taper nitrogen; hold feed during hottest weeks.
- pruning
- Pinch back soft spring growth; wait until fall for structure.
- pests disease
- Check for powdery mildew in humid weather.
- summer protection
- Ensure root ball doesn’t overheat—shade or pot insulation.
Late Summer08-11 — 08-31
- watering
- Maintain consistent moisture as growth slows.
- fertilization
- Apply phosphorus high feed to support root health.
Early Fall09-01 — 09-30
- watering
- Gradually reduce watering frequency.
- fertilization
- Final feed of the season to build winter reserves.
- pruning
- Structural wiring/pruning before leaf color onset.
- wiring
- Optimal time for wiring with active sap.
- development
- Encourage hardening of summer growth.
Mid Fall10-01 — 10-31
- watering
- Reduce watering as foliage falls.
Late Fall11-01 — 11-15
- watering
- Water sparingly; avoid soggy pots in cool temps.
- winter protection
- Begin root insulation; move pots to sheltered area.
Early Winter11-16 — 12-31
- watering
- Minimal watering only during dry periods.
- winter protection
- Keep protected from frost; mulched pots preferred.
Mid Winter01-01 — 01-31
- watering
- Check moisture monthly; prevent dehydration.
- pests disease
- Scan for winter insect eggs or scale.
- winter protection
- Ensure root insulation through coldest weeks.
Late Winter02-01 — 02-14
- watering
- Resume regular watering as buds begin swelling.
- repotting
- Begin planning for spring repot; prep soil and tools.
