How to Cut Bonsai Roots

Root Trimming

• 1

  Place the bonsai into the large plastic tray to catch any dirt and debris generated by the root-trimming process.

• 2

  Cut or untwist the anchor wires underneath the pot holding the bonsai's root mass in the pot. Clip off any twists that could damage the roots as the wires are pulled out through the root mass.

• 3

  Slide a small knife around the inside edge of the pot to release the root mass from the edge of the pot.

• 4

  Gently grasp the trunk of the bonsai and lift it carefully from the pot.

• 5

  Remove the drainage mesh and old anchor wire that held the root mass in the pot and clean the pot.

• 6

  Brush the soil from the surface roots using the nylon brush or bonsai rake. Brush gently but firmly from the trunk to the outer edges of the root mass until the upper roots are exposed for examination.

• 7

  Comb the soil and grit gently from the outer and bottom roots with the bonsai rake and root pick or chopsticks. If the bonsai is heavy, comb the soil out of the bottom roots and set the bonsai carefully on an upturned pot so the roots hang down around the sides of the pot as you clean them. Be careful not to damage or tear the roots.

• 8

  Trim about one-third of the roots from the root mass using sharp scissors. Cut out roots that circle back over other roots, thicker roots, damaged roots or surface roots that do not add to the aesthetic look of the nebari, the exposed roots at the base of the trunk. Trim back any fine roots enough so they do not need to be folded to fit in the pot. Keep as many of the fine roots as possible because the bonsai absorbs nutrients and water through them.

• 9

  Cut a few small wedges into the root base from the outside edge to allow fresh soil access to the middle of the root mass. This only needs to be done if the root mass is very dense.

Repotting

• 10

  Place pieces of drainage mesh over the holes in the bottom of the pot and spread a thin layer of grit or small stones over the bottom of the pot, if required.

• 11

  Spread a thin layer of soil over the grit or stones and place the root mass into the pot.

• 12

  Cut new anchor wires and position them around the root mass, threading them through the drainage mesh at the bottom of the pot. Do not tighten them down at this point.

• 13

  Add bonsai soil carefully around the root mass, using chopsticks to push the soil carefully into holes around the roots. Position the tree as you add soil and fasten the wire once the tree is in place. Secure the root mass firmly into the pot because any movement risks damaging the new roots. Continue to add soil around the root mass until the root mass is covered as desired.

• 14

  Tap the pot gently to remove any remaining air holes and tamp the soil down. Cover the soil with your preferred medium, such as Japanese Akadama clay or moss.

• 15

  Water the bonsai more than normal to saturate the soil and flush any small particulates out, then place it in a protected position out of the wind and protected from strong sun.