Repotting guide

When & how to repot Monkey Puzzle Tree (Araucaria araucana)

Also called monkey puzzle tree, Chilean pine, pehuén.

More about monkey puzzle tree

About Monkey Puzzle Tree

Araucaria araucana · also called monkey puzzle tree, Chilean pine · edible

The monkey puzzle is an ancient, architectural evergreen from the Chilean and Argentine Andes, instantly recognisable by its stiff, spiralling triangular leaves and umbrella crown. Female trees bear large cones packed with edible piñones, a traditional Mapuche food. It is slow but very long-lived, cold-hardy, and needs full sun, deep moist-but-drained soil, and patience.

Mature size: Reaches 20-30 m tall and 8-12 m wide over many decades; a large landscape tree needing space, not a small-garden plant.

Watch for — Honey fungus (Armillaria): Monkey puzzles are notably susceptible to this root-rot fungus, which causes branch dieback and death. Avoid sites with a history of Armillaria and keep trees unstressed.

How to tell monkey puzzle tree needs repotting

Repotting on a calendar is less reliable than reading the plant. For monkey puzzle tree, watch for these signs:

Roots circling the bottom of the module or pot, or poking out of the drainage holes.
The seedling dries out within a day and growth has visibly stalled.
Roots are white and matted in a tight spiral when you tip the plant out.
It has outgrown its current container for the stage of the season — pot monkey puzzle tree on before it becomes hard root-bound.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot monkey puzzle tree

Pot on seedlings as they grow; not a perennial repot. Monkey Puzzle Treeis grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Slow-growing, upright evergreen conifer with a distinctive symmetrical, domed crown of horizontal branches; lower limbs are shed with age to reveal a clean trunk..

What size pot to step monkey puzzle tree up to

Pot monkey puzzle tree on gradually — a seedling jumped straight into a huge pot sits in cold, wet, airless soil and stalls. Step up one or two sizes at a time as the roots fill each container, finishing in a large final pot or the ground. The aim is roots that never circle and never check.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot monkey puzzle tree

Pot monkey puzzle tree on through the active growing season, whenever roots fill the current container — there is no single date, just "before it becomes root-bound". Avoid potting on during a cold snap.

Step-by-step: repotting monkey puzzle tree

Pot on before it is root-bound. Check monkey puzzle tree regularly; move it up as soon as roots reach the edge of the cell or pot, not after they have circled.
Step up one or two sizes. Choose the next container up — not a giant one. Cold, wet, unused soil around a small root system stalls seedlings.
Knock it out gently. Support the stem, tip the pot, and ease the rootball out without breaking it. A little teasing of circled roots at the base is fine.
Pot into rich mix. Set it into fresh deep, fertile, well-drained loam, slightly acidic at the same depth (tomatoes are the exception — they can go deeper to root along the stem).
Water in and grow on. Water well, keep it in good light, and resume feeding once it is established and growing again.

Aftercare

Water monkey puzzle tree in well and keep it in bright light; a freshly potted-on seedling can wilt for a day while roots settle, so do not overcompensate by drowning it. Do not fertilise for about 1 week — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for monkey puzzle tree

Monkey Puzzle Tree wants deep, fertile, well-drained loam, slightly acidic. Prefers a rich, moisture-retentive yet free-draining soil. Avoid thin chalky or permanently wet ground; mulch to keep roots cool and steady. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting monkey puzzle tree — frequently asked questions

How often should you repot monkey puzzle tree?

Pot on seedlings as they grow; not a perennial repot for monkey puzzle tree. Monkey Puzzle Tree is a seasonal crop, so you pot it on as a growing plant rather than repotting a perennial. Step seedlings up gradually into deep, fertile, well-drained loam, slightly acidic so the roots never circle the cell, ending in a large final container. A root-bound transplant stalls and never fully recovers.

What size pot does monkey puzzle tree need?

When is the best time of year to repot monkey puzzle tree?

Can you put monkey puzzle tree straight into a much bigger pot?

No. Even a fast-growing monkey puzzle tree should only go up one pot size at a time. A vastly oversized pot holds a reservoir of wet soil the roots cannot reach, which stays cold and soggy and rots the roots — the opposite of what you wanted.

Should you fertilise monkey puzzle tree after repotting?

Not immediately. Wait about 1 week after repotting monkey puzzle tree. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.