How to Repot a Bonsai Made Easy Without the Mess or Stress

Repotting bonsai trees is essential in achieving healthy growth and pleasing aesthetics. All too often bonsai tree growth is stunted by repotting, which takes too long or is simply not done at all. However, we should exercise caution when it comes to hasty repotting. We will examine these issues and more. 

Although we will expand on it later, the basic procedure for repotting bonsai trees is as follows: 

• Select a pot. Large pots allow for more growth. It is important to understand, regardless, that when repotting bonsai trees we don’t need to change the pot if we don’t want to.
• Set a mesh screen on the bottom of the pot and wire it in place. Prepare some wiring to set your bonsai tree in place as well. 
• Carefully remove the bonsai tree from the old pot and trim excess roots. Avoid removing more than 30% of these roots, more or less. 
• Re-soil your bonsai tree. There are several different mixtures that can be used. A mixture of akadama, gravel and compost is quite typical. 
• Water the bonsai tree and let it rest, protected from winds. 

Understanding Bonsai Growth Needs

Bonsai trees may be small, but they have big needs when it comes to root health. Over time, their roots fill the pot, making it difficult for them to absorb nutrients and water efficiently. Without repotting, your bonsai can become root-bound, leading to stunted growth, poor soil aeration, and even disease. Repotting helps refresh the soil, trim excessive roots, and create space for new growth, keeping your miniature tree thriving.

So, how do you know when it’s time to repot? Keep an eye out for slowed growth, water draining too quickly through the soil, or roots pushing up from the pot’s surface. If your tree seems to struggle despite regular care, it’s likely in need of a new home.

Repotting offers multiple benefits beyond just making space. It replenishes nutrients, enhances soil drainage, and allows you to inspect and trim unhealthy roots. A well-timed repot keeps your bonsai strong, resilient, and beautiful.

When to Repot Bonsai Trees?

It is important not to take too long to repot. There are several factors that will tell a bonsai owner when to make this happen. 

The size of the bonsai pot and the tree species greatly influence the timing of repotting. Fast growing species must be repotted every couple years. Younger bonsai trees need to be repotted once a year. They evidently grow fast and roots can become a problem quite quickly. Alternatively, other species, and particularly mature trees, are to be repotted every four years or so.  Note that these are rough guidelines. 

Some of the signs that suggest repotting a bonsai tree is necessary are:

• Slow rate of growth compared to the rate of growth previously. 
• The water uptake has decreased due to excessive leakage underneath. 
• Reduction of aesthetics: noticeably smaller leaves, for instance, or discoloration/yellowing of leaves. 
• Falling of leaves, which occurs too early/suddenly. 

What to Look for Before Repotting

Repotting bonsai trees is not to be done haphazardly. It is vital that we observe our trees carefully and the signs that point towards the need to repot. Repotting will essentially protect our tree from choking itself off from the soil, water and nutrients through excess rooting. 

Early spring is an ideal moment to check on a bonsai tree’s roots. Remove the tree carefully from its pot and observe the roots. If the roots circle around each other, and constitute a sort of block, so to speak, it is time to repot. Such mesh of roots displace the soil, pushing it away from the tree and thus essentially starving the bonsai tree. If, however, the roots are still within soil, repotting need not take place just yet. 

Materials

Having the right materials is very handy when repotting bonsai trees. Things such as root rakes, scissors, wire cutters and chopsticks are standard. A roothook is quite useful to remove excess roots and soil when we lift the tree from its pot. As usual, wire is a handy material (copper or aluminum). 

Pots are evidently another item to consider. Occasionally it will be possible to repot the bonsai tree in the same old pot. Other times, we may want to repot in an entirely new pot.  

Finally, there are several types of soil that can be used when repotting bonsai trees. Compost soil, gravel, akadama, and obviously water are a typical mix. 

Steps to Repotting Bonsai Trees: In Detail 

How to Repot a Bonsai tree

1. If the bonsai tree is anchored, cut the wire from beneath the pot.
2. Remove the bonsai tree from its pot. 
3. Evaluate the roots: Are the roots still inside the soil? Conversely, are they circling around the pot? Have they formed a solid block, without access to soil or even water? 
4. Use the chopstick to remove the old soil around the bonsai tree and beneath it. Be careful with the roots and don’t place any unnecessary stress on them. Note that this cleansing must be prudent; pines for one, require about half of the roots to be left untouched for proper health. 
5. Trim very long roots with the scissors. In general, however, be careful both with this trimming and with the aforementioned cleansing of roots. It is best not to prune bonsai more than 30% of roots at one time. Also, cleanse soil, but don’t worry about getting rid of it all. In any case, observation and further trimming may take place the following spring. 
6. Once pruning of roots has taken place, cover the drainage holes with mesh first, to avoid the new soil from seeping out. 
7. Set a wire to anchor the bonsai tree in the new pot.  
8. Now, re-soil the pot. This process is best done in several stages:
   1. Set a thin layer of heavy soil below, such as lava rock or akadama. This will be our main drainage layer. 
   2. On top of this drainage soil, set another thin layer of Bonsai soil as such. 
   3. Place the bonsai tree back in the pot. Use the wires set before to better support it in place. 
   4. Add soil around the bonsai tree and use the chopstick to make sure this soil seeps in correctly.
9. After re-soiling is over, water the bonsai tree and let it rest. Protect it from strong winds for a couple of months. 
10. Monitor the bonsai tree in the weeks and months after repotting and notice its progress. 

Check out: How to Repot a Cactus without a Hassle

Bonsai Repotting Soil Mix

Soil mixture is a major consideration when repotting bonsai trees. There are two guidelines that we should understand. 

First, the soil mix must be able to drain and prevent the roots from rotting. Second, this soil mixture needs to be able to absorb enough water to nourish the bonsai tree. 

Varying the soil mix and its ratios of mixture also depends on the environment. Wet climates, for one, can make do with mixtures that are more draining (such as mixtures with more lava rock). 

A typical soil setup is something like this: akadama, gravel, and compost in a 2:1:1 ratio. Note, however, that there are several types of mixes that are possible. Pumice, akadama, and lava rock are another fairly popular mix. 

FAQs on Repotting Bonsai