Convert root-over-rock to exposed root?

[SharonP]

I started this Ficus natalensis as a root-over-rock July 2024, exposed the rock by May 2025, and it's thriving. I constantly have to cut it back--see photo after recent haircut. For now, it's in the same plastic container I buried the rock in when I was first starting the ROR.

I recently realized the rock I choose is too big/heavy to ever move this tree (and its rock) into a ceramic bonsai pot. The tree is just 10" tall (a little bigger than a shohin), but the rock is about 5 lb. In addition, the rock is ugly and the same color as the roots, making it hard to see that it's even a ROR.

One option I just thought of was to carefully untangle the roots from the rock and repot this as an exposed-root tree instead. Has anybody tried this? Pros or cons? Thanks in advance.

 

[nuttiest]

I like it. I like to grow schefflera on a smooth rock and make a birdcage root formatiion.

 

[Shibui]

It can be done, depending how many of the roots have fused together. I sometimes have failed ROR when no roots around the back of the rock, in which case the expanding roots push the tree away from the rock. Most of those end up as exposed root trees.

You will have to see how the trunk and roots look before making the final decision. Sometimes exposed root just looks awkward and doesn't look good.
Next option would be to layer higher up the root system to get a formal upright bonsai.

 

[rockm]

I wouldn't remove that from the rock. I would thin the roots a bit so the rock is more visible. If you try to pry this off, the end result is going to look odd for a very very long time.

This is a pretty decent ROR and you've done well getting it done. Would be a shame to waste it. If it's too heavy for you to move, that's obviously a problem, though.

 

[SharonP]

Thanks to everybody for the good advice and options. I started looking at photos online, and see that even huge rocks, triple the size of mine. are used with normal, small, ceramic pots without breaking. I had thought the rock was so heavy that any pot would instantly crack when I picked up the tree to move to better light, move between indoors/outdoors seasonally, etc. Apparently, that's not a huge issue.

@rockm, you mentioned thinning the roots. I started a Serissa the same week as this one, and that one just made like 6 beautiful thick roots over the rock and looks great. Even got an award at our club show after just 7 months as a ROR and the judge praised how mature it looked.

This ficus is the opposite , soooo messy, with a zillion roots and aerial roots. Would you recommend just picking like 4-6 of the thickest roots to keep and then cutting off all the thin roots in between? I didn't know if that would cause branch die-off, but I agree it would look a lot better. I'll probably have to stay on top of this one for life, as it makes roots about 10x faster than it makes branches.

 

[rockm]

Thanks to everybody for the good advice and options. I started looking at photos online, and see that even huge rocks, triple the size of mine. are used with normal, small, ceramic pots without breaking. I had thought the rock was so heavy that any pot would instantly crack when I picked up the tree to move to better light, move between indoors/outdoors seasonally, etc. Apparently, that's not a huge issue.

@rockm, you mentioned thinning the roots. I started a Serissa the same week as this one, and that one just made like 6 beautiful thick roots over the rock and looks great. Even got an award at our club show after just 7 months as a ROR and the judge praised how mature it looked.

This ficus is the opposite , soooo messy, with a zillion roots and aerial roots. Would you recommend just picking like 4-6 of the thickest roots to keep and then cutting off all the thin roots in between? I didn't know if that would cause branch die-off, but I agree it would look a lot better. I'll probably have to stay on top of this one for life, as it makes roots about 10x faster than it makes branches.

That is what I would do, only leave more than six or seven. Do it now while the weather is hot. This will slow down as we head towards autumn.

I’d pick the roots that most aesthetically pleasing that flow down the rock. Obviously leave the most dominant but leave some that look promising.

If your concerned about top die back thin less aggressively with an eye towards doing more thinning next year.

I understand that natal figs are not as vigorous as say Benjamina, so whatever you’re doing with this one keep at it.

 

[rockm]

BTW the trick with using large stones in containers is make sure to distribute the weight as evenly as possible. In other words make sure the rock isn’t coming in contact with the pot bottom on a single sharp point or similar.

 

[SharonP]

Thank you, I appreciate the great advice!

 

[SharonP]

I went out and started removing the roots and made a few discoveries:

- Probably over half the roots over the rock were from the aerial roots, which this tree puts out weekly. So I decided to remove all the aerial roots and the chunk of lower branch (with aerial roots) and remove all that junk.

- There were tons more hair roots that I would have expected. It turns out I hadn't cleaned off the rock much after exposing it from being buried. Lots of soil had settled into the crevices, and roots weren't bothering to grown down the rock--just setting up shop in those "puddles" of soil. So I blasted it with air and water to remove the dirt.

- Some of the rock had crumbled--I obviously didn't choose a very good rock to use. Removing the rock crumbles left some of the main roots up in the air, more like exposed root than ROR.

Anyway, I addressed all of the above, and it's much improved. Now to see if it bounces back after removing about half of its root system...

FRONT:



BACK:



It's wanting to be a formal upright, so when I repot it next, I'll orient the rock to correct the lean in the trunk.

Thanks again for the advice!