Repotting and Rootpruning Bonsai - Part II

Page 3 of 3

Page 3 of 3:


After the tree has been root pruned, it is then possible to place the tree back into a bonsai pot. If the pot has not already been prepared, it should be done now.

bonsai repot

The root-pruned Elm and the fully-prepared bonsai pot.

bonsai repot

Cover the base of the pot with a layer of soil creating a small mound where the tree is to be positioned, so that when finally planted, the outer edge of the nebari (surface roots), if there is one, sits just above the height of the rim of the pot. Offer the tree upto the pot; if it will not sit high enough, take it out again and add more soil. If the tree sits too high in the pot, remove some of the soil layer, if it still stands proud of the rim it may be necessary to remove some of the roots from the bottom of the rootball.

anchoring wires for bonsai

Place the tree into the pot and ensure that the exact front of the tree is facing forward. Tie it in firmly with the anchorage wires so that the tree is unable to be rocked about by the wind in the coming weeks whilst new roots are growing.

bonsai root bamboo

Start feeding in new soil around the edge of the rootball. Add fresh soil around the rootball and work it in with a bamboo tool.

bonsai repot

Use your fingertips to gently firm in the new soil; it is much easier to feel where the empty cavities and voids are within the rootball this way.

When the soil is fully worked in, water the tree very thoroughly to ensure that the soil is fully wetted and any remaining air pockets are removed. Watering will settle the soil and it may be necessary to apply more soil to the surface. Re-water until it is certain that the soil has fully settled throughout the pot and all air pockets in the soil have been removed. It should be emphasised, the tree should be held in position by the anchor wires, not by the soil.

bonsai watering in

Watering-in the Elm bonsai. The soil is given a heavy soaking of water to remove air pockets in the soil.


Most trees will show no reaction to repotting and continue on throughout spring without any problems. Some extra care should be taken however in the six weeks after repotting to ensure the health of the tree. Avoid exposure to severe frosts, the tree should be regarded as less hardy than normal for six weeks after repotting. Do not place the tree where it is exposed to strong winds or intense sun. This is particularly necessary with evergreens as the increase in loss of moisture through the leaves as a result of the wind and sun will increase the stress on the newly pruned roots. It is likely that under windy or hot conditions, coniferous species will lose foliage if the reduced rootball is not able to replace evaporated moisture. If foliage does start to dry out on evergreens, provide a shady position out of the wind and mist the foliage regularly.

elm bonsai repot

The repotted English or Field Elm bonsai/Ulmus minor. Height 17”/42cm. Pot by Victor Harris of Erin Pottery.

>>Repotting and Rootpruning Bonsai - Part II : Page 1 2 3