How To Repot Juniper Bonsai: A Step-By-Step Guide

 

When to repot juniper bonsai

Which time of the year to repot

Timing is crucial when it comes to repotting juniper bonsai or any bonsai for that matter.  Choosing the right time ensures that your tree recovers quickly and minimizes stress during the process.  While the specific timing may vary depending on the climate and the juniper species, there are some general guidelines to follow.

Best time to repot

The best time of the year to repot any juniper bonsai is very late winter to early spring, just before the tree enters its growth phase again.  Repotting at this time of the year gives your tree ample time to develop a healthy root system during the growing season.

Be careful if the temperature gets cold below 40°F (5°C) anytime after repotting.  If it does, your tree needs some protection from the cold, like putting it in a shed or greenhouse.

If you live in a warmer region, you may be able to repot in the beginning of fall as well.  But when you do, do not make a hard prune on the root system.  Your tree may not have enough time to recover before winter comes.

When not to repot

Avoid repotting during summer and winter.  The growth of bonsai roots largely decelerates under a hot and stressful summer climate, after vigorous growth in spring.  There is almost no root growth during winter and repotting can make them go through too much stress.

How often to repot

In general, juniper bonsai trees should be repotted every 2 to 3 years when they are young and every 3 to 4 years when they mature.

Before repotting, check the soil and roots to identify soil degradation and poor drainage.  If the soil particles are broken down and no longer provide good drainage, you have to repot your trees despite the recommended frequency.

What you need to repot juniper bonsai

To repot a juniper bonsai tree, you need;

1. new bonsai soil mix
2. a pot bottom net
3. a (new) bonsai pot
4. bonsai scissors
5. wooden chopsticks and
6. string/wire.

Bonsai soil mix

Recommended soil mix for juniper bonsai is;

-Akadama: 50%
-Lava rock: 25%
-Pumice: 25%

Premixed

If you are looking to use premixed bonsai soil, the following product I found on Amazon best matches the mixture ratio for juniper bonsai (Bonsai Soil by The Bonsai Supply).

Bonsai Soil by The Bonsai Supply

(Link to Amazon)

Other premixed soil products for juniper (or coniferous) bonsai trees often contain tree bark.  These may be good if you live in a hot and dry region like California or Texas but if not, they may keep too much moisture for juniper trees which prefer to be kept in well-drained, drier soil rather than very wet one.

Homemade

If you want to make your own soil mix at home, here are the ingredients you need.

(Link to Amazon)

I explained everything you need to know about juniper bonsai soil in the following post.  If you are interested, please check it out.

As for Akadama, it is unique in the sense that it checks all the boxes to be a good bonsai soil.  But it is quite expensive to purchase outside Japan.  If you do not want to spend that much on Akadama, vermiculite is a good candidate for an Akadama alternative.

[Burpee Organic Vermiculite]

Burpee Organic Vermiculite

(Link to Amazon)

To know how to make bonsai soil at home and more about Akadama alternatives, please check the following posts.

If you are thinking about reusing bonsai soil that has been used for several years, I wouldn’t recommend it.  Common bonsai soils have a lifespan of 2 to 7 years and it may not be in good condition anymore.

Bonsai pot

When selecting a pot for your juniper bonsai, choose one made of stoneware if it is available.  Stoneware pots have an earthy look that complements the rustic beauty of juniper bonsai.  The naturalistic texture and color found in stoneware pots can create harmony with your tree and its style.

Look for one with a rectangular or square shape.  The rectangular/square shape has a rigid and vigorous impression that matches the austere look of juniper bonsai trees.  As to the color, dull reddish colors like purple and brown ones have a remarkable contrast with the beautiful green foliage throughout the year.

If your trees are in the training phase, a clay pot is ideal for their healthy growth.

To know more about which pot type to choose, the following post might be helpful.

Bonsai scissors

Bonsai scissors are different from ordinary garden pruners.  They are made especially for the purpose of pruning tiny leaves in dense foliage and cutting off roots cleanly.  Ordinary bypass pruning scissors are not for fine pruning and there is a risk of damaging roots and tearing branches.

These traditional bonsai scissors with a long shank (Ashinaga) shown below are my first choice because they are for general-purpose bonsai pruning that is good for both branch and root cutting.

Wazakura Ashinaga Bonsai Scissors

(Link to Amazon)

For more about bonsai scissors, please check the following post.