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Plant care

Coral Bark Maple (Coral Bark Japanese Maple) care

Acer palmatum 'Sango-kaku'

Also called Coral Bark Japanese Maple, Sango Kaku Maple.

RHS H6USDA 5–8Pet-safeIndoor 5–7 m tall

Watering rhythm

5-7days

When the top 3–5 cm of soil is dry, roughly every 5–7 days in summer; reduce in winter

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Light

Bright indirect light (just back from a sunny window)

Soil

Moist, humus-rich, well-drained slightly acidic loam or ericaceous mix; pH 5.5–6.5

Humidity

40–70%

Temp

−20 to 30°C

Pet safety

Pet-safe

Mature size

5–7 m tall

Care at a glance

Light

Coral Bark Maple is what florists mean by "bright spot, no direct sun" — close enough to a south or east window to feel the brightness, with a sheer curtain or a few feet of distance keeping the sun off the leaves. Best stem colour develops in full to partial sun. Morning sun with afternoon shade is ideal in warmer climates. Full sun is well tolerated in the UK. Shelter from cold, drying winds to prevent bark splitting and leaf scorch. A phone lux-meter at the leaf surface should read 1,500-3,000 lux at noon.

Watering

Water coral bark maple when the top 3–5 cm of soil is dry, roughly every 5–7 days in summer; reduce in winter. The actual day count varies with pot size, light, and season — the finger test (or lifting the pot to feel its weight) is more reliable than a fixed calendar. Empty any drainage saucer afterwards so the pot isn't sitting in water. Consistent moisture throughout the growing season maintains stem and leaf health. Container plants must not be allowed to dry out. Reduce watering after leaf fall but keep roots from completely drying during winter.

Soil and pot

Coral Bark Maple grows best in moist, humus-rich, well-drained slightly acidic loam or ericaceous mix; ph 5.5–6.5. Incorporate leaf mould or composted bark into planting soil. Refresh container compost every 2–3 years. Good drainage is critical to prevent root disease. Mulch around the base conserves moisture and regulates root temperature. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Coral Bark Maple sits happiest at around 40–70% humidity and −20 to 30°C (−4 to 86°F). Content in typical temperate garden humidity. Extra humidity measures are unnecessary outdoors in the UK. In very dry indoor or heated environments, ensure adequate root moisture rather than misting. If you keep the room above −20 to 30°C year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed coral bark maple sparingly. Apply a slow-release balanced granular fertiliser in early spring. A second light application in early summer supports vigorous growth. Avoid fertilising after late July — soft autumn growth is susceptible to frost damage and reduces stem colour intensity. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on coral bark maple in the Growli community. Each is annotated with the most common cause so you know where to start.

  • Reduced stem colour — Fades on older wood — rejuvenate by pruning some stems to the base to encourage bright young growth.
  • Leaf scorch — Brown leaf margins from drought, hot afternoon sun, or wind exposure; improve watering consistency and provide shelter.
  • Verticillium wilt — Dieback of individual branches; prune back to healthy wood and sterilise tools between cuts.
  • Aphids on new growth — Common in spring; treat with insecticidal soap or neem oil if population is high.
  • Late frost damage — Emerging spring foliage is frost-sensitive; protect with fleece if late frost threatens after bud-break.

Companion plants

Coral Bark Maple pairs well with Nandina, Camellia, Mahonia, and Snowdrops. These are species with similar light and water needs, so you can group them in the same room or on the same shelf and water as a batch.

Propagation

Grafted onto Acer palmatum seedling rootstocks to reproduce cultivar characteristics; this is the standard commercial method. Hardwood cuttings in autumn are occasionally attempted but have low success rates. Plants cannot be reliably reproduced true-to-type from seed. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Coral Bark Maple is pet-safe. Acer palmatum 'Sango-kaku' is not listed by the ASPCA as toxic to cats, dogs, or horses. Japanese maples as a group are not considered toxic in the veterinary literature for common companion animals. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Coral Bark Maple care — frequently asked questions

What is the common name for Acer palmatum 'Sango-kaku'?

Acer palmatum 'Sango-kaku' is most commonly called Coral Bark Maple, but it is also known as Coral Bark Japanese Maple, Sango Kaku Maple. The names refer to the same species, so care instructions for Coral Bark Maple apply identically to anything sold as Coral Bark Japanese Maple.

How much light does coral bark maple need?

Coral Bark Maple grows best in bright indirect light (just back from a sunny window). Best stem colour develops in full to partial sun. Morning sun with afternoon shade is ideal in warmer climates. Full sun is well tolerated in the UK. Shelter from cold, drying winds to prevent bark splitting and leaf scorch.

How often should I water coral bark maple?

Water coral bark maple when the top 3–5 cm of soil is dry, roughly every 5–7 days in summer; reduce in winter. Consistent moisture throughout the growing season maintains stem and leaf health. Container plants must not be allowed to dry out. Reduce watering after leaf fall but keep roots from completely drying during winter. The finger-test (or lifting the pot to feel its weight) beats a fixed weekly calendar because pot size, light, and season all change how fast the soil dries.

Is coral bark maple toxic to cats and dogs?

Coral Bark Maple is pet-safe. Acer palmatum 'Sango-kaku' is not listed by the ASPCA as toxic to cats, dogs, or horses. Japanese maples as a group are not considered toxic in the veterinary literature for common companion animals.

What USDA hardiness zone does coral bark maple grow in?

Coral Bark Maple is rated for USDA zone 5–8 and RHS hardiness H6. Outside that range, grow it as a container plant that overwinters indoors before the first hard frost.

Coral Bark Maple deep-dive guides

Every aspect of coral bark maple care, each with its own calibrated guide:

Featured in these plant shortlists

Coral Bark Maple qualifies for 10 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

Related guides

Coral Bark Maple is also commonly called Coral Bark Japanese Maple or Sango Kaku Maple.