Planting advice

A Japanese maple succeeds thanks to two simple things: a sensible site (light, wind) and a healthy root environment (moist but well-drained). Here are our nursery guidelines for a clean, no-nonsense planting.

Planting in the ground

When to plant?
  • Autumn (frost-free): ideal—your tree establishes before the following summer.
  • Late winter / early spring: also excellent, especially in colder climates.

Avoid planting during prolonged frost or when the soil is waterlogged.

Choosing the right spot
  • Light: morning sun / bright partial shade is the easiest.
  • Wind: a sheltered location almost always gives cleaner foliage and more regular growth.
  • Soil: moist but draining. The real enemy is standing water in winter.
Preparing the soil (the key point)
  • If your soil is light and drains well: a gentle improvement is enough (well-decomposed organic matter).
  • If your soil is clayey / compact: the priority is to aerate and improve drainage (structure).

Practical tip: after rain, if water sits in the same spot for a long time, adapt the planting (a slight mound, improved drainage).

How to plant (simple method)
  1. Soak the rootball for 10–15 minutes if it is dry.
  2. Dig a wide hole: about 2× the width of the rootball (not necessarily very deep).
  3. Loosen the sides of the hole (to avoid the “buried pot” effect).
  4. Set at the right level: the top of the rootball / root collar level with the soil—never deeply buried (and never bury the graft union).
  5. Backfill with the excavated soil, optionally lightly improved (without excess).
  6. Water in thoroughly to settle soil around the rootball.
  7. Mulch straight away (without piling mulch against the trunk).
Common mistakes in the ground
  • Planting too deep (buried collar).
  • Planting in a winter-wet area without adaptation.
  • Adding a lot of “pure compost” into clay soil (it can create a basin that holds water).

Planting in a container

Choosing the right pot
  • Size: the larger the pot, the more stable the culture (temperature, watering).
  • Drainage: essential (generous holes).
  • Saucer: possible, but never leave standing water permanently.

Simple tip: slightly raise the pot (small feet) so water can drain freely.

Potting mix: moist but very free-draining

In a container, the mix must stay airy. A good principle:

  • a quality horticultural base (structure + humus),
  • plus a mineral component for drainage (lava rock/pozzolan, pumice, horticultural grit).

Example mix (adjust to your local climate):

  • 60–70% quality composted bark/structured potting mix (not bagged “ericaceous soil”)
  • 30–40% mineral (pozzolan / pumice)

The idea: a mix that absorbs water but doesn’t compact.

How to pot up (clean and long-lasting)
  1. Check the pot drains properly (holes clear).
  2. Add a first layer of mix, then position the rootball.
  3. Level: the top of the rootball slightly below the rim (2–3 cm) to make watering easier.
  4. Backfill and firm lightly (do not compact).
  5. Water generously once.
Common mistakes in containers
  • Pot too small (unstable, dries out too fast).
  • Mix too fine / too “peaty” (compacts).
  • Water left standing in a saucer.

If you’re unsure

If you’d like us to guide you toward the safest planting option, please tell us:

  • container or in the ground,
  • exposure (morning sun / full sun / partial shade),
  • wind (sheltered / exposed),
  • soil type (free-draining / clay),
  • and the cultivar or habit you’re aiming for.

Ericaceous soil: why we don’t recommend it (despite the common belief)

You often read that a Japanese maple “needs ericaceous soil”. In practice, bagged ericaceous soil is very often too fine and too water-retentive (often peat-based), which can:

  • compact over time (lack of air for roots),
  • hold water and encourage root suffocation in wet conditions,
  • become hydrophobic when dry (water runs off and penetrates poorly),
  • create an unstable medium if used alone or in large proportions.

What a Japanese maple really wants is not “magic acidic soil”, but a living, humus-rich soil that is above all well-drained—moist without stagnant water.

Instead: improve your soil with well-matured organic matter + an airy structure, and in containers use a mixed organic/mineral substrate.

FAQ

Should I plant a Japanese maple in ericaceous soil?

We don’t recommend it: bagged ericaceous soil is often too fine, compacts, and holds too much water. Japanese maples prefer a humus-rich, free-draining root environment.

When should I plant a Japanese maple?

Autumn (frost-free) is ideal; otherwise late winter/early spring also works very well.

What potting mix for a Japanese maple in a container?

An airy mix: a structured organic base + a draining mineral component (pumice/pozzolan). Avoid very fine mixes.

My soil is clay—can I plant in the ground?

Yes, but you must improve structure and drainage. Otherwise, container growing can be easier to control.

How deep should I plant?

Keep the root collar level with the soil. Planting too deep is a common cause of decline.