Repotting is an essential part of bonsai. Often an overlooked element but one that is so crucial. To the long term health and sustainability of your trees. It is worth taking the time to ensure that your trees have a well developed root system, able to support the tree and the development of the tree, over time. It is also essential that you check the roots annually. Even if you do not carry out a full repot, as this is often where problems can start in the soil or with the roots. There are many mediums to grow bonsai trees in and it is important that you find the right soils for the species of trees you have as well as the conditions you grow your trees in. The growing medium may need to change over time as the root system develops as the requirements of the different root types can vary and by ensuring the correct growing medium is used will encourage an efficient root system which in turn aids with the overall growth and development of the whole tree. Below are a few examples of repotting by our club members from this year.
Repotting an Acer
Really pleased with the root development on this Acer, it has a healthy fibrous root pad but for this year I have increased the depth of the pot to aid with the development of the tree as the original pot depth was around 4cm. The ramification has been slow so I am and trying a 7cm depth pot to provide the tree with a greater soil volume and access to moisture and nutrients to see if this improves the back budding and crown development of the tree now that the roots are well developed.
Repotting a Hawthorn
Repotting a Zelkova
The condition of this small Zelkova has declined in the past year and one of the reasons was drying out in hot weather last year due to having an insufficient root system to aid with moisture uptake. More work is needed on developing an improved fibrous root pad as opposed to the longer more stringy root system it currently has.
Repotting a Ginkgo group
This small group of Ginkgo are developing well but the pot size is a bit small to maintain the tree all year round in when the weather is very hot in the summer so this year it will be repotted into a slightly larger pot to aid with development of the trees and to improve the overall health of the group.
Repotting a Mame Cryptomeria
This is a fabulous little tree originating as an air layer from a Club member and the root development has been superb. It continues to develop good roots and also develops aerial roots too which is fun.
Repotting a Cork Bark Chinese Elm
This Cork Bark Chinese Elm has been a slow one to develop a strong fibrous root pad, it started with no root pad at all but just cut large structural roots and over the past few years it has been root pruned annually to aid with the development of the fibrous element of the root system. This is now forming but still a long way off. It has affected the stability of the broom crown development and caused the loss of branches and twigs as the balance of the crown development is not in line with that of the an advanced functioning fibrous root pad. To reduce the stress on the tree due to the lack of balance the crown has been reduced heavily last year and this has reduced the branch loss and aided with foliage and crown stability. Hopefully as the roots improved each year this will allow the improved development once again of the broom style crown.
Repotting a Shohin Ginkgo
This has been a fun tree to develop a better root system on, and the fleshly roots are starting to form a dense pad of roots from the main structural root ends. The root tips are very healthy and the overall condition of the root plate is good. There is still work to do to improve the nebari on one side as there are still crossing roots which look unsightly at the back and more work is needed to over time remove these but grow new ones to replace them but positive results so far in its development.