I have a rock, in search for suitable roots to grow over it...

[Fonz]

This summer I brought home this rock from Austria, used a power grinder to flatten the bottom. I also have a bunch of acer palmatum, buergerianum, black pine, zelkova, ginkgo, .... seedlings. Not really that familiar with creating ROR plantings.
Is this rock suitable? Do I use 1 seedling or several (let the trunks fuse while the roots go different ways along the rock).
All suggestions welcome and appreciated.

 

[Shibui]

The rock is absolutely suitable. Nice shape and some good features for root over rock.
Acer buergeranum (trident maple) is more suitable than Acer palamtum. Trident roots are stronger and grow faster so you can achieve a result much quicker with trident maple.
A single tree will be enough. Adding extra trunks and fusing will just add complexity you do not need.

Root over rock is easy enough. Getting a good root over rock requires some technique and also some luck. Not every attempt turns out to be great.

For some tips and techniques for trident maple root over rock you might like to read some posts on my site - Shibui Bonsai root over rock posts
Good luck with this project.

 

[Fonz]

The rock is absolutely suitable. Nice shape and some good features for root over rock.
Acer buergeranum (trident maple) is more suitable than Acer palamtum. Trident roots are stronger and grow faster so you can achieve a result much quicker with trident maple.
A single tree will be enough. Adding extra trunks and fusing will just add complexity you do not need.

Root over rock is easy enough. Getting a good root over rock requires some technique and also some luck. Not every attempt turns out to be great.

For some tips and techniques for trident maple root over rock you might like to read some posts on my site - Shibui Bonsai root over rock posts
Good luck with this project.

Great posts on your blog!
What time of year do yu check on your roots and wrap them back in? Fall?

edit: nevermind, I see that post is dated late august which means late winter in your part of the world

 

[Wires_Guy_wires]

This is the type of rock I've seen a lot in the alps.
Why not take a risk and go for a spruce?

 

[DonovanC]

I saw a demo last year using trident maples and electrical tape. Several cuttings mindfully wrapped around the rock then tightly wrapped together at the top with electric tape.

 

[HorseloverFat]

I saw a demo last year using trident maples and electrical tape. Several cuttings mindfully wrapped around the rock then tightly wrapped together at the top with electric tape.View attachment 328859

That’s funny! I used electrical tape on some ROR pom seedlings.... real stealthy like, cause I figured it was a big “no-no”

 

[Fonz]

This is the type of rock I've seen a lot in the alps.
Why not take a risk and go for a spruce?

Because I don't have a spruce
I do have some Larix seedlings, they grow they grow there a lot too.

 

[Fonz]

I saw a demo last year using trident maples and electrical tape. Several cuttings mindfully wrapped around the rock then tightly wrapped together at the top with electric tape.View attachment 328859

Yeah that's a technique described in Andrea Merigiolli's "Bonsai Maples" book. That's an option too. But letting seedlings fuse on a rock sounds like a double challenge

 

[Wires_Guy_wires]

Because I don't have a spruce
I do have some Larix seedlings, they grow they grow there a lot too.

Larch would work well! Especially in fall.
But then again, so would ginkgo. Yellow and grey would give a nice contrast.
I think the ginkgo would be best, because it keeps the foliage longer in fall.

 

[DonovanC]

That’s funny! I used electrical tape on some ROR pom seedlings.... real stealthy like, cause I figured it was a big “no-no”

It may be a “no-no,” lol, but the demo was by Ken Huth, who is a large part of the Ohio bonsai scene. The demo was at the Columbus Bonsai Society’s annual “Huth-apoloza.” He brings like piles of very small saplings/cuttings, which are sold for one or two dollars each.
But I guess Ken is kind of known for his unorthodox ways. He commonly uses wire to fuse tridents (different from the root over rock method) and leaves the wire to be swallowed by the tree. And he stands by keeping procumbens and shimpaku indoors -at least the assertion that it’s possible.
So my thoughts are, there are definite fundamentals in bonsai, but there’s a ton of room for ones own methods and experiments.

 

[DonovanC]

...letting seedlings fuse on a rock sounds like a double challenge

How so?
I never attempted the technique, I’m not (at least not at this point in life) a maple person. So I merely took it as an interesting concept rather than something I’d like to attempt.

 

[James W.]

Trident maple is easiest. Chinese elm and JBP are also options.

The problem I have had using tape to secure a tree to a rock is that the adhesive does not always break down fast enough so when the tree is dug up to check and fix roots the next year or two it can be problematic removing the tape from the roots. I have been using cotton twine with fair success.

As far as fusing, it would add another factor into an already complex project. Finding a rock is easy (difficulty 1), finding a nice rock is not as easy (difficulty 1.5), finding a great rock is harder (difficulty 2). Growing a tree is easy (difficulty 1), training an acceptable tree is hard (difficulty 3), developing a great tree is unachievable for many of us (difficulty 5). Many people have grown fused trees (difficulty 2), some people have grown nice bonsai by fusing trees (difficulty 3), I am unsure how many great bonsai are a result of fusing trees (difficulty 4).
Rock (difficulty 1) x tree (difficulty 1) x fusing (difficulty 2) = difficulty 2
Nice rock (1.5) x acceptable bonsai (3) x acceptable fusing (3) = difficulty 13.5
Great rock (2) x great bonsai (5) x great fusing (4) = difficulty 40

 

[leatherback]

I do have some Larix seedlings, they grow they grow there a lot too.

Check Nick Lenz Root-over statue!

For a first trial I would use a trident.

 

[Shibui]

Rock (difficulty 1) x tree (difficulty 1) x fusing (difficulty 2) = difficulty 2
Nice rock (1.5) x acceptable bonsai (3) x acceptable fusing (3) = difficulty 13.5
Great rock (2) x great bonsai (5) x great fusing (4) = difficulty 40

The difficulty rating is actually far higher than you have given.
Getting the roots to grow in good places on the rock adds difficulty of around 2 or 3. Getting the trunk and roots to make a pleasing combination with the shape of the rock adds extra difficulty 2 or 3. You have not yet even started to thicken the trunk or grow branches yet which all adds complexity and possibilities for something to go wrong.
These are just some of the factors that prompted me to warn that not every attempt will end up as a winner.

Tape is OK provided the rock is approximately convex. Tape cannot hold roots close to the rock in deeper crevices or hollow parts. That's why I developed the alfoil technique. It can be moulded into most hollows so the roots are held close to the rock.
Twine has the same problems. In addition when tridents are grown in the ground they love to put out new lateral roots just under the surface. Such roots will grow straight through your twine and grow way quicker than the roots you carefully arranged on the rock leading to huge taper issues, large scars, etc when they are cut off. Often the roots on the rock just die when a new lateral emerges and grows strong. Foil prevents any roots from escaping. All new roots must grow down the surface of the rock and will add to the root system you started with.

 

[James W.]

The difficulty rating is actually far higher than you have given.
Getting the roots to grow in good places on the rock adds difficulty of around 2 or 3. Getting the trunk and roots to make a pleasing combination with the shape of the rock adds extra difficulty 2 or 3. You have not yet even started to thicken the trunk or grow branches yet which all adds complexity and possibilities for something to go wrong.
These are just some of the factors that prompted me to warn that not every attempt will end up as a winner.

Tape is OK provided the rock is approximately convex. Tape cannot hold roots close to the rock in deeper crevices or hollow parts. That's why I developed the alfoil technique. It can be moulded into most hollows so the roots are held close to the rock.
Twine has the same problems. In addition when tridents are grown in the ground they love to put out new lateral roots just under the surface. Such roots will grow straight through your twine and grow way quicker than the roots you carefully arranged on the rock leading to huge taper issues, large scars, etc when they are cut off. Often the roots on the rock just die when a new lateral emerges and grows strong. Foil prevents any roots from escaping. All new roots must grow down the surface of the rock and will add to the root system you started with.

I use rocks or pieces of wood under the twine to force roots into crevices or hollows. Aluminum foil or other coverings go on top of the twine to keep new roots corralled.

 

[bonsaiBart]

I'm cooler than a polar bears toenails

 

[DonovanC]

I'm cooler than a polar bears toenails

Prove it.

 

[Shibui]

I use rocks or pieces of wood under the twine to force roots into crevices or hollows. Aluminum foil or other coverings go on top of the twine to keep new roots corralled.

I've also used various objects to hold roots into low parts of rocks with varying degrees of success. None as good as wrapping well with foil.
Presumably your twine is wrapped more or less horizontally around the rocks? What does that do to the direction of new roots that emerge while the tree is buried? Care to show some of the trees developed this way?

 

[James W.]

I've also used various objects to hold roots into low parts of rocks with varying degrees of success. None as good as wrapping well with foil.
Presumably your twine is wrapped more or less horizontally around the rocks? What does that do to the direction of new roots that emerge while the tree is buried? Care to show some of the trees developed this way?

Best I have going so far can be seen on this thread.
I have others growing, nothing presentable yet.

We are kind of hijacking @Fonz thread here. Do you want to discuss our theories and experiences elsewhere?

 

[Fonz]

Best I have going so far can be seen on this thread.
I have others growing, nothing presentable yet.

We are kind of hijacking @Fonz thread here. Do you want to discuss our theories and experiences elsewhere?

No, no please continue, very interesting. No kidding.