Repotting and Thinning Mature Ficus and Jades: Steps for Maintenance of Historic Bonsai

Source material: August 2020

            Recently, I randomly ran into someone who inherited some historic bonsai trees that I had previously been caring for alongside the former owner. Mrs. E had 3 different indoor bonsai - a Ficus benjamina dwarf variety, a Ficus macrocarpa, and a jade (Crassula ovata) grove - all 20-30 years old or more. While Mrs. E had an excellent garden and a proven track record for the maintenance watering and care of these trees, she did not have the nuanced experience in bonsai for more serious operations such as repotting and styling. This is why I and other Columbus Bonsai Society members before me were asked to come help her every few years to keep the trees healthy and not let them get too unshapely. She was my first bonsai client when I moved back to Columbus. Normally Mrs. E sat out with me, and we'd chat while I was doing the bonsai work. In this article you can see the before and after from their repotting when I first met her and these trees.

            In Part 2 next week, I will share an "Open Letter to First Time Bonsai Owners" which is adapted from the email I sent to the new owners of these trees. My goal was to provide the essential points needed to keep the trees happy and healthy and to assess their needs for a novice bonsai artist especially for dealing with precious older trees as your first foray into bonsai.

Sections:

1. Repotting of Historic, Mature Tropical Ficus and Jade Bonsai (this week)
1. Ficus benjamina
2. Ficus macrocarpa
3. Crassula ovata, aka Jade
2. Open Letter to First Time Bonsai Owners (next week)
1. How to assess a bonsai's immediate care needs
2. More recent pictures from pruning these historic Ficus bonsai.

In Vivo Bonsai Announcements/Upcoming Events in Columbus

• April 12, 2025 - 4TH Annual Columbus Bonsai Society INVASIVE Alliance / Yamadori Study Group Dig. I am organizing this free event for the 4th year in a row. As I have written about previously, come out and learn your native vs invasive plant ID, get some advice on digging trees and getting them to live, and on turning our home-grown species from wild bonsai/yamadori into successful bonsai. RSVP here by 4/11.
• April 27, 2025 - Columbus Bonsai Society Monthly meeting on Techniques for All Stages of Deciduous Development. I will be leading the discussion and presentation. All members are encouraged to bring one or more deciduous tree and think ahead on what techniques or next steps you think that tree needs for this growing season. Facebook event here.
• May 03, 2025 - Bonsai and Coffee. Intro to Indoor Bonsai Workshop at Casa Cacao Cafe in Columbus, OH hosted by yours truly. Sign up here.

After repotting and pruning on these historic, mature ficus bonsai.

I. Ficus benjamina dwarf

Before pruning and repotting. The tree was very dense both in regards to its foliage and rootball. Some wires were to move branches also previously applied that had done their job by now and could be removed.

The tree was repotted into new soil with some root pruning to remove circling roots as old trees develop those easily when not repotted for long periods. Some sphagnum moss was applied at the top to help retain moisture since this was done in summer.

Also, the top of the tree was pruned to allow more light into the interior. Each branch was pruned back to interior most leaves since Ficus benjamina has a reputation for not backbudding or regrowing on bare branches. The branches I pruned off, I then defoliated and attempted to strike as cuttings, with some success.

II. Ficus macrocarpa

This tree was also dense in its canopy and rootball. There was little interior branching and the foliage had gradually pushed outward to expand the profile of the tree, placing less emphasis on the trunk. By pruning to allow light in and stimulate backbudding we can start to correct this.

Repot in progress. You can see the tree has some impressive aerial roots that grow over the trunk. You can also see the previous caretaker utilized a soil mix with turface and possibly some crushed granite? I'm not sure what the black rocks are. See the types of roots generated in this mix in the next closeup.

You can see this turface based soil has generated some fine roots which is what we need in high numbers to develop strong trees. I did observe though the small particle size could have led to more water retention than I would normally like. Of course, in the course of the repot, I changed it to my own bonsai soil that I typically use.

Ficus macrocarpa after pruning to thin the canopy and after repotting.

III. Crassula ovata, also known as Jade

Jades are a common houseplant and a very resilient species for bonsai. I use them for my introductory bonsai workshops often for this reason, but we must understand how to handle their flaws to maximize their potential. 

Here is the before shot. The clump of trees was crowded by branches that were stuck into the soil to propagation. I always propagate in separate pots from the parent tree that is in progress on its bonsai training so as to not interfere with the actual vision of the trees that I intend to create.

Here in this closeup you can see the old soil type - also turface mixed with some organics as it was with the two ficus previously. You can also see the character of jade bark as it ages and turns more brown and flakey. In this way, a succulent that is not truly woody can appear to have a woody trunk and can work as bonsai. 

The soil held onto a lot of water, so the jades did not need to grow much roots. Jades are succulent so they don't need much roots in the first place to survive. More drainage should be helpful to promote more robust roots.

The soil was especially organic deeper down, almost like potting soil mixed with turface. Again, far from my ideal bonsai soil, but it seemed to serve the trees well enough for a while.

After rinsing out the pot. In hindsight, I should have drilled the plastic or substituted the pot to make bigger drainage holes. This would also help these succulents to sit in less water. Unfortunately, this was the only pot the owner had on hand.

Added some tie down wires to help tie the forest in place. Could add more if more drainage/wire holes were drilled.

My lava, pumice, and pine bark soil. The particle size is definitely a bit bigger than the old soil which should help with drainage until the bark breaks down in a few years.

The finished version of the jade forest. Note that the clutter has been reduced so we can better appreciate the most mature trees in the front. Smaller trees are in the back to give the sense of depth perception. The tops of the trees have also been pruned back some, although they could probably be pruned back even further if desired. My focus here was mostly on the forest arrangement but regular pruning on jades is necessary to keep them from getting top heavy and to develop strategically interesting branch lines via "clip and grow". I will explain this concept more in depth in the June Central Ohio Cactus and Succulent Society meeting where I am presenting on that topic.

Closeup of the trunks of the jade forest. Note that each trunk has been arranged so that each can be seen from the front view with some natural but not too much overlap. The spacing between the trunks in a bonsai forest should be uneven to make it look natural.