Fiches de culture

Create a bonsai from a seed: step-by-step guide

Jeune érable du Japon en formation dans un pot de culture en terre cuite, son tronc ligaturé au fil d'aluminium, posé sur un banc de bois usé
In this article 8

A bonsai is not a dwarf species. It is an ordinary tree — the same one that would reach twenty meters in a forest — kept small through continuous work on its roots and branches. What miniaturizes it is constraint, not genetics.

Starting from a seed rather than an already trained specimen changes everything: you control the silhouette from day one, the cost is negligible, and the tree adapts to your conditions from germination onward. In return, you have to accept a timetable measured in years.

Choosing your species

The criterion is not the appearance of the mature tree but the size of its leaves: they shrink with training, but never enough to make naturally large foliage look proportionate.

Reliable choices for beginners

  • Japanese maple (Acer palmatum) — the great classic. Fine foliage, spectacular autumn colors, and abundant branching. Requires 8 to 12 weeks of cold stratification.
  • Japanese privet (Ligustrum japonicum) — probably the most tolerant of all. Fast-growing, and tolerant of pruning and watering mistakes. The best choice for a first attempt.
  • Wild olive (Olea europaea sylvestris) — small leaves, a trunk that quickly develops character, and drought-resistant. Excellent in mild climates.
  • Barberry (Berberis vulgaris) — hardy, small foliage, interesting bark.

To learn more

  • Aleppo pine and Atlas cedar — conifers require a different technique (pinching rather than pruning) but produce the most evocative silhouettes.
  • Italian cypress and bald cypress — the latter tolerates waterlogged soils remarkably well, which is rare.
  • Ginkgo biloba — unique foliage, golden yellow in autumn. Difficult to densify its branching: this is a bonsai best trained in a simple upright style.
  • Chinese redbud — pink flowers on old wood, spectacular. Scarify the seeds before stratification.
  • Pomegranate — small leaves, bright red flowers, miniature fruits. One of the most accessible fruiting bonsai trees.
  • Albizia, jacaranda, royal poinciana — tropical species to grow indoors, with very fine compound foliage.
Species to avoid for a first attempt

Naturally large foliage — magnolia, persimmon, guava — remains disproportionate even after years of defoliation, and species with very long germination times are discouraging before they produce anything. They remain worthwhile, but for a second tree.

Step 1 — germination

This is where most attempts fail, and almost always for the same reason: dormancy has not been broken.

  • Cold stratification — essential for most temperate species: maple, pine, cedar, dog rose, Chinese redbud. Allow 4 to 12 weeks at 1 to 5 °C in a moist substrate. The complete method is in Cold stratification.
  • Scarification — for hard-coated seeds: Chinese redbud, albizia, flamboyant. Lightly file them or soak them for 24 hours in lukewarm water.
  • Constant warmth — for tropical species: jacaranda, flamboyant, guava. At least 25 °C.

Sow in deep pots, not seed trays: these species develop a taproot within the first few weeks, and a shallow container makes it spiral permanently. Well-draining substrate — seed-starting mix lightened with one-third sand or perlite.

Young oak seedling removed from its deep pot, its white taproot extending the entire height of the container
Within a year, the taproot often reaches the bottom of the pot while the stem is not even ten centimeters tall: the tree builds its roots before its silhouette. This is the tip that is cut off at the first repotting.
A Collection That Can Wait Until the Second Spring

Germination in these species takes place over several weeks, and some of the seeds do not sprout until a year later, after a second period of cold. Keep the pots for one more winter, in the shade, and never let them dry out completely: a pot discarded after a month has almost always been discarded too soon.

Step 2 — let it thicken (years 1 to 3)

This is the most common misconception: people want to miniaturize the tree immediately. But a thick trunk can only be obtained by letting the tree grow freely. A tree restricted from its first year will remain a twig all its life.

During these three years:

  • Grow it in a generously sized pot, or even in the ground — that is what produces the finest trunks, by far.
  • Let the shoots grow freely. You will cut them later; each leaf fuels thickening.
  • Only one useful intervention: at the end of the first year, cut the taproot during the first repotting. This forces the development of fine lateral roots, the basis of the future nebari — the visible spread of roots at the surface, which makes the tree appear anchored.
  • Outdoors for all temperate species, including in winter. A maple kept indoors will decline — it needs its dormancy period.
Three years before the first pruning

Years 1 to 3: free growth, no shaping. Only one cut during this entire period: pruning the taproot at the end of the first year. Structural pruning only begins between the third and fifth years, when the trunk has finally reached the desired thickness. Restricting the tree earlier does not slow it down: it permanently stunts it.

Step 3 — shaping (from year 3 onward)

Once the trunk has reached the desired thickness, the work changes in nature: reduce and structure it.

Structural pruning

At the end of winter, when there is no frost, before bud break. Remove anything that conflicts with the desired silhouette: crossing branches, branches parallel to the trunk, shoots growing inward, and one of the two branches emerging from the same point.

Maintenance pruning

During the growing season: let the shoot develop five or six leaves, then cut it back to two. Repeated, this action densifies the branching and gradually reduces leaf size. It is what makes a bonsai, more than anything else.

The tip of a maple shoot cut back to two leaves, with the fresh, clean cut visible just above the upper leaf
Make the cut just above the retained pair of leaves, without leaving a stub: a bare piece of stem dries out without producing new growth and leaves an unnecessary scar.

Wiring

Aluminum wire wound in a 45° spiral, without tightening. It guides branches and the trunk while the wood lignifies, then is removed once the shape has been acquired.

Bare aluminum wire wound in an ascending spiral around the trunk of a young maple, with the bare bark remaining visible between each turn
One turn approximately every two centimeters: enough to hold the branch, but loose enough for the bark to breathe. The wire should remain loose enough for a fingernail to fit underneath.
Forgotten wire permanently scars the bark

The trunk thickens while the wire stays put: it eventually grows into the wood and leaves a sunken spiral that nothing can erase. Check monthly, and always remove the wire by cutting it piece by piece—unwinding it breaks the branches it was holding.

Repotting

Every two or three years for a young tree, at the end of winter. Untangle the root ball, prune one-third of the roots, and replant in a well-draining substrate. This repeated root pruning is what keeps the tree small—and forces it to produce the fine rootlets on which it depends.

Routine care

  • Watering — this is the critical point. A bonsai pot is shallow and dries quickly: in summer, often once a day. Water until it drains out through the holes, then let the top centimeter dry before watering again.
  • Substrate — very well-draining, never potting soil alone. A mix of akadama, pumice, and bark, or, failing that, potting soil lightened with half coarse sand and pumice.
  • Fertilizer — little and often, only during the growing season. A well-draining substrate retains little: small, regular applications are better than a heavy dose.
Never bring a temperate tree indoors in winter

Maple, pine, cedar, privet: these species need their cold dormancy, and spending a winter in a warm living room exhausts them within one or two seasons. This is the mistake that kills the most gifted bonsai trees. They stay outdoors year-round—and what needs protection from severe frost is the pot, not the tree: roots freeze much faster in a few centimeters of substrate than in the ground.

The actual timeline

Period What happens
Year 0 Stratification followed by sowing. Irregular germination
Year 1 Free growth. First repotting at the end of the year, cutting the taproot
Years 2–3 Free growth to thicken the trunk. No shaping
Years 3–5 First structural pruning, beginning wiring
Years 5–10 Refining the branching, reducing the foliage, moving into a bonsai pot
Beyond Care and the tree continues to improve for decades

Let's be clear: a bonsai grown from seed takes five to ten years to look like something. If you want quick results, buy an already-trained tree. If you want a long-term project and a tree that will be entirely your own, sow seeds.

Frequently asked questions

Can you make a bonsai from any species?

Technically, almost, but not all species produce a harmonious result. Large-leaved species remain disproportionate, even after years of defoliation. Choose a small-leaved species from the outset.

Do I need an indoor or outdoor bonsai?

Nearly all temperate species are outdoor trees: they need winter cold. Only tropical species — jacaranda, flamboyant, guava, neem — can be kept indoors, and they require plenty of light there.

Why aren't my seeds sprouting?

Nine times out of ten, dormancy has not been broken. Check whether the species requires stratification, scarification, or both. Only then should you consider the temperature and freshness of the batch.

When should you move it into a bonsai pot?

Not before the trunk has reached the desired thickness — generally in the fifth year or later. A shallow pot considerably slows thickening: it is an end goal, not a starting point.

Can you harvest seeds from a garden tree?

Yes, and it is an excellent way to get started: maple, hornbeam, elm, dog rose. Harvest when ripe, then sow or stratify promptly. See How to store your seeds.

How many seeds should you sow?

Several, systematically. The germination rate of these species is often low, and above all: out of ten seedlings, two or three will have an interesting form or trunk movement. Selection is part of the work.

Key points

The essentials in three lines

First, break dormancy: this is where nine out of ten attempts fail. Then let the tree grow freely for three years — advice that goes against intuition but makes all the difference, because miniaturization only comes later, through repeated pruning and repotting. Start with a Japanese privet or a maple, sow several, and accept the timeline: it is a ten-year project, and that is what makes it worthwhile.

To learn more

Discover our collection of trees, shrubs and bonsais — species requiring stratification are indicated on each product page.

Read more

Mains d'un homme tenant un tamis à cadre de bois au-dessus d'un plateau, la balle légère s'envolant tandis que les graines propres restent dans le plateau
Girolles dans la litière d'une hêtraie claire, chapeaux jaune d'œuf en entonnoir et plis épais fourchus descendant sur le pied.

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