Repotting is not optional when growing bonsai.
Why? Because after growing in the same pot for some time, the tree will become pot bound. This means there is no room for new roots to grow and the plant will have a hard time getting the nutrients it needs to survive.
To be a successful bonsai grower you need to know when to re-pot (and when not to) as well as how to re-pot. How often you need to re-pot is dependent on the species of plant you use for bonsai and you should look into a care guide for your plant to help you decide. So in this article I’ll just focus on how to re-pot.
Step One: Gather needed supplies
Before you begin re-potting you should make sure you have two things ready–the soil and the pot. If you’ll be using a new pot make sure you have a cover for the drainage holes to prevent soil from leaving the pot after watering the plant. You can cover the holes with plastic mesh and keep it in place with bonsai wire.
The new soil you add to the pot should be free draining. That means avoiding ordinary garden soil and regular potting compost. You’ll want to get instead a general purpose bonsai soil or make your own soil.
Step Two: Prepare your tree for potting
The next step in re-potting your bonsai is to prepare your tree for potting. To do this prune unwanted foliage, and branches. And to make re-potting easier, reduce your watering schedule by about half for at least a week. This will make the soil dryer and make it a lot easier to remove the plant from the pot.
Step Three: Remove your tree from the pot
Gently remove the tree from the pot using a tongue depressor to help separate the soil from the sides of the pot. Then pull the tree and the soil out of the pot. You should now be able to see the root ball. Once you have the root ball out, you need to remove the soil from it. This can be done by hand or you can use a root hook. You should brush away the soil from the trunk and take every precaution not to damage the roots. Use a fine bristled paintbrush to remove soil stuck to the roots.
Step Four: Remove soil from the roots
The next step involves combing the roots to straighten them out. Use a pointed stick or a chopstick for the purpose. Prune the excess circling roots. The aim is to remove 1/3 of the overall root mass. Carefully examine the roots and if you find any diseased or dead roots, you should remove them.
Step Five: Prepare the pot for the tree
Wash the pot. Then cover the drainage holes with plastic mesh. Get a wire to anchor the bonsai and put it through two of the holes. Leave long ends on the wire to anchor the tree in place. Bend the wires back so that when you add soil to the pot they don’t get in the way.
Step Six: Put the tree in the pot
Lay a layer of grit at the bottom of the container and then add the bonsai soil. Position your bonsai into the container and then add soil where needed. Put the wires across the root ball. Twist them together to hold the tree in place. Add more soil and gently work it into the root mass until the pot is full. Add some water and then putmoist moss over the soil.
Your bonsai will need extra care after it has been re-potted. After some time you will see new foliage on your bonsai and you’ll know that you have done a good job at re-potting your bonsai.
By Rodney Daut