Bonsai are usually re-potted and re-pruned every few years. Re-potting prevents them from being pot-bound and encourages the development of new feeder roots allowing the tree to absorb moisture more efficiently. You will also have to change the soil to prevent it from becoming rancid and hindering growth.
Where to buy bonsai pots?
It is very easy to access and buy bonsai pots online. Use the box below to refine your search:
Types of bonsai pots
You can tell that a bonsai needs repotting if water takes a long time to drain through the soil or if the roots are crowding round the sides.
To repot, carefully lift the tree from its current pot by tilting it to one side and trying to move it from the base of the trunk. You can’t pull too hard on the trunk – so if this doesn’t work, try tapping the pot with the side of your hand to loosen the root ball or poke a stick through the drainage holes and’push’ the root ball out.
Next, with a chopstick, knitting needle, metal hook or similar, eliminate any moss or accent plants and carefully try to brush and untangle the roots. Start at the edge and slowly work around. Attempt to’comb’ and’tug’ rather than to’pull’ at the roots – for danger of damaging or tearing some very important main roots.
After this has been done – continue to shake and brush off the soil until roughly one third to half of the original soil has been taken away from the edge and base of the root ball.
It would now be a fantastic idea to spray the roots with water to make sure that they do not dry out so they won’t have too much dirt on them when it is time to pruning the roots.
To prune the roots, use very sharp cutters. There are bonsai root pruning scissors commercially available, however you could just use a normal pair of bonsai clippers.
In case you’ve washed away most loose soil the scissors will stay sharp, but if they must cut through soil in addition to the roots – they will get blunt very quickly and need sharpening.
Start by cutting the thick, old brown roots that have come near the edge of the pot and are restricting the development of the young’feeder roots’. Remove a third to a half of these – being careful that you do not remove too many feeder roots in the procedure.
Next, prune the thinner roots that hang below the depth of the pot by trimming all of them into an appropriate shape the pot will adapt. This should be a shape that fits comfortably into the kettle with a 1-2 cm (1/2 to 3/4 in) space between the edges.
The demanding part of this repotting is currently over – if you think that you’ve cut a lot of feeder roots away, the tree will be disadvantaged but you probably will get away with it as new roots will grow from the cuts.
Clean the first pot thoroughly or select a new pot that is more suited to the tree and cover the drainage holes with easy wire mesh. As the plant will now be unstable in the new pot as it’s nothing to anchor it you need to generate some anchors to prevent the tree from falling over from winds or from being transferred.
Thread some wire through the drainage holes or specially designed holes for anchoring and leave for later use. This wire doesn’t need to be very thick.
Add a thin layer of gravel to aid drainage and then a layer of dirt. Moving the tree around, decide a basic position for it (usually off-center and slightly to the rear of the pot) and make a little mound it will sit on. You can now put your bonsai on the mound by gently nestling it in and spreading out its roots evenly throughout along with the soil.
Once you’re happy with the height and position of your tree (it will stay like that for 1-2 years), choose the wires that you threaded and twist them together (usually with the aid of pliers) over the primary root ball of the tree until it’s held firmly (but not too tight) and won’t rock. Because these wires are quite unsightly, you can remove them in a few months time when the tree has settled .
Add more soil up to the bottom of the trunk – which should be just below the bottom of the pot. Tap the side of the pot with your hands to ensure that the soil gets settled and there are no gaps around the roots. Use your chopstick to incorporate the roots to the soil and to be certain they are placed correctly.
Once the soil has been applied, you now have the choice to add supplementary features such as stones, moss, accent plants or gravel to improve the design. When employing moss – be careful that the majority of the original soil is cut off from the floor before you plant it and the moss is not too big or vigorous for the pot or tree.
Now you should thoroughly water the tree – being conscious that the soil level may settle farther and more soil might have to be added. Put the tree in a position where it won’t receive extremes in temperature (i.e. not direct sunlight ) and where it will be able to recuperate. Do not fertilize at this time as this can burn or cause stress to the plant. You can feed in around a month though, once the roots have regained.
Note that in order to balance out the extensive pruning you’ve just done on the roots you need to prune the branches of the bonsai as well so that it can recover faster and not be disadvantaged further. Root growth usually does equal branch development.
Since bonsai is essentially meant to be grown outdoors, you must pay attention to the care of your tree with the changing seasons.