Bonsai Techniques & Methods

Structural Pruning (Heavy Pruning)

Performed in late winter or early spring (before the growth flush). Involves removing large branches, reducing height, or establishing the primary branch structure. Always use a concave cutter for clean wounds. Apply cut paste to wounds larger than a pencil diameter on deciduous species. Never remove more than one-third of the tree's foliage in a single session.

Maintenance Pruning (Pinching)

Ongoing trimming throughout the growing season to maintain shape and redirect energy. Use sharp shears to cut new growth back to 1-2 leaf pairs. On conifers, pinch soft candles by hand (never cut with scissors — crushed needle ends turn brown). The goal is to keep the tree's silhouette tight while encouraging back-budding on inner branches.

Key principle: Prune strong areas hard, weak areas lightly. This redistributes energy from dominant (usually apical) growth to weaker inner and lower branches, creating the balanced vigor needed for a convincing bonsai silhouette.

Application Rules

• Wire at 45-degree angles along the branch — never perpendicular
• Always wire two branches with one piece of wire (anchor at the trunk)
• Wire from thick branches to thin, trunk to tip
• Wire diameter should be ~1/3 the branch diameter
• Wrap snugly but not tight — one wire thickness of gap to the bark
• Bend immediately after wiring while positioning is fresh in your mind

Timing & Removal

Wire deciduous species in early spring before leaves emerge (bare branches are easier to wrap). Wire conifers in late autumn/winter when sap flow is reduced. Check wire monthly — fast-growing species can develop wire scars within weeks. Remove wire by cutting each coil individually with wire cutters; never unwind, as this damages the bark.

When to Repot

The ideal window is when buds are swelling but haven't yet opened (late winter/early spring). At this stage, the tree has maximum stored energy and root growth is about to explode. Signs a tree needs repotting: water pools on the surface instead of draining, roots circle the pot bottom, or the tree lifts out of its container.

The Process

1. Prepare the pot: cover drainage holes with mesh, thread anchor wires
2. Remove tree from old pot, gently rake out roots with a root hook
3. Trim roots — remove up to 1/3 of the root mass, targeting thick downward roots
4. Position tree in new pot, secure with anchor wires
5. Fill with pre-sieved soil, working it into root gaps with a chopstick
6. Water thoroughly until water runs clear from drainage holes
7. Keep in shade, protected from wind, for 2-3 weeks while roots recover

Warning: Never defoliate conifers, newly repotted trees, weak trees, or trees that haven't been fertilized. Defoliation is a high-energy technique — performing it on a weak tree can be fatal.

Jin (Deadwood Branch)

Score the bark at the base of the branch with jin pliers, then peel strips of bark downward toward the tip. Crush and tear the wood fibers to create a natural, weathered appearance — never cut cleanly. Taper the jin by removing more wood toward the tip. Apply lime sulfur to bleach and preserve.

Shari (Deadwood Trunk)

A strip of bark removed from the trunk to expose the wood beneath. Mark the desired shari line with a marker, then carefully score along the edges with a sharp knife. Peel the bark within the marked area using jin pliers. Critical rule: never remove bark all the way around the trunk — always leave at least one continuous live vein connecting the roots to the canopy.

Uro (Hollow Trunk)

A hollowed section of trunk that simulates centuries of natural decay. Created using power tools (die grinders, Dremel) to carve out the heartwood while preserving the outer sapwood and bark. The most advanced and dramatic of the deadwood techniques. Primarily used on collected conifers (juniper, pine) where the natural trunk already has areas of dead wood.