Starting seedlings through holes in metal plates is not the only way to grow good nebari. I also grow many trees just by regular root pruning to control and direct root growth. Here are some photos to show that method.
Most seedlings develop a strong vertical root to ensure the little tree has access to deeper damp soil so it can survive a dry summer. In bonsai we don’t want deep roots we prefer to see well spread strong lateral surface roots. First step is to cut the vertical root. I usually look for a spot where there are several lateral roots around the trunk and cut just below.
Often I need to also remove any single higher roots. If I leave those to grow they tend to grow faster and create lopsided root system. The remaining lateral roots don’t have to be right opposite. In fact it can be better if roots on one side are higher so the seedling can be planted at an angle with remaining roots horizontal. Initial leaning trunk tends to yield a better informal upright tree.
I also cut the trunk shorter to help push multiple leaders the following summer. Multiple leaders give me better options for bends in the trunk and better taper.
These trimmed seedlings are then potted into pots for a year’s growth. After a year I should end up with something like this small trident. Note that this is not the same tree as above but it is representative of tridents after initial root pruning as shown above.
In the second winter the roots are trimmed again. Note how well the tree has responded to the previous radical root pruning with a mass of lateral roots around the area I cut last winter.
At this stage the tree can go back into a grow pot for controlled development or into the ground for faster growth. The following tree was started using this root pruning technique followed by 2 years in the grow beds. Tridents in the grow beds are dug and root pruned every winter at Shibui Bonsai
In the last post I showed a couple of the trident maples I’m currently digging and pruning.
You may have noticed the very horizontal root spread.
These tridents have been developed using the ‘plate’ method.
Start with a piece of metal sheet with a hole drilled through the middle.
Mine have been cut from old aluminium roadsigns I bought at the scrap metal yard but any sheet metal will do. Some growers use wall or floor tiles but they can be difficult to drill and I found that growing trident roots exert enormous pressure and broke the tiles. CDs are also crushed by growing roots but I’ve used these pieces over and over for nearly 10 years now with excellent results.
I start with seedlings. Thread a seedling through the hole.
Don’t go too far through. if any roots are above the metal one usually grows far quicker and gives an unbalanced root structure.
Note that I’ve placed the trunk on an angle through the sheet. If you want a vertical trunk stand yours upright but make the choice now because next year it will be too late to make changes.
Plant the tree with its metal collar about 1cm under the soil. Too deep an you’re likely to get more roots than you need and they may not be evenly spread.
As the trunks grow fatter the metal starts to cut off circulation in the tree. The tree responds by producing callus and then new roots just above the restricted area. The only option for those new roots is to grow out over the metal in a flat plane. Eventually circulation to the roots under the metal is completely cut off and those roots will die off leaving your tree with a new, flat root system.
I find it far better to keep these trees in pots in the nursery for the first year. In the ground, new roots are forming just as the heat of summer hits and if they don’t make it over the plate and down into deeper soil there is a risk that they may dry out on hot days. Daily watering ensures they will grow and survive until, after a year, the tree looks something like this
Here’s a closer shot of the new roots above the metal plate.
Now those new roots above the metal are pruned quite short.
Then the tree can be planted back into a grow pot or into the ground to thicken up. remember not to plant too deep. Tridents love to grow new roots right near the surface so if these roots are buried deep the tree will grow new ones that may not be as good.
Another year of growth and I now have a thickened trident with developing horizontal nebari. A side benefit is that the base of the trunks tends to swell and buttress far more than with other techniques. You can see that there’s no real advantage in using larger plates. To get good root ramification the roots need to be pruned quite short each year and larger sheets just make it harder for the new roots to reach moisture deeper in the soil.
Another year or 2 and I have the sort of tree shown at the start of this post.
I find that threading trident seedlings is an easy way to produce superior root spread on trident maples but I have also used the same technique on Japanese maples and even on Japanese black pines. It should work with most tree species and I’d be interested to hear from growers who have used it on other trees.
At Shibui Bonsai I have finished digging the new root over rock trees so it is time to get on with the rest of the trident maples.
here’s one of the tridents I dug up this week.
It seems that I use a few different techniques when growing trees in the ground for bonsai
Let’s focus on the roots for a start. I dig most deciduous trees every winter and prune the roots. I know that many other growers claim this slows down development and maybe it does but the little I lose, if any, in size is more than made up for in nebari.
Just so it is easier to see, I’ve washed the roots in water and done a rough trim.
Last year the roots were cut very short – about 2cm from the trunk. You can now see the result. Lots of new, white roots have grown from the cut ends. These new roots will thicken and gradually merge together to form the characteristic plate like nebari in coming years. Those new roots will now be cut short again, probably 1/2 cm this time and, of course, each one will grow a number of new roots again. Just as branch ramification is valued above ground, Root ramification below ground should be the aim of good bonsai growers.
Now both roots and branches have been shortened ready to go back into the ground or into a pot for further development.
Here’s another trident maple after trimming both roots and branches.
You may note that I’ve left a few extra leaders on both these trees. I remove any that I think are growing in the wrong direction or in poor positions but I generally leave several possible new possible leaders as insurance. When the tree is growing well next summer I can make final decisions about which trunk line to follow and the others will be pruned then.
Winter is a great time of year at Shibui Bonsai. I get to dig up the trees in the grow beds and see what has been achieved over the past year or 2.
The root over rock tridents are the most exciting because I can’t even get a glimpse of the rock/root arrangement until I dig them and unwrap the rock. It is almost like opening Christmas presents. You never know what you’ll find.
Tear off the foil to find out how well those roots have grown and grabbed the rock.
The best ROR have roots that wrap right round and hold the rock tight. Roots should be growing in close contact with the rock. Like they grew there naturally.
In this case, both sides look really attractive. that will give more options for styling the tree later.
At this stage the top is just cut back and only obviously unusable branches are removed completely. I’ve left several possible new leaders to see which looks better when they grow next summer.
Here are a couple more that I dug and pruned today.
Actually, the tree above got a bit carried away. I was aiming for a nice small tree on a small rock – obviously the tree had other ideas and now I’ll have to develop a larger trident on a small rock..
And here’s another one. Plenty of well placed roots holding tight to the rock. A great start to another new Root over Rock trident maple.
Something I don’t look forward to seeing is roots growing through the foil.
Trident maples seem to love growing lateral surface roots. Much more than most other species and if one grows too strong it is likely that the roots closer to the rock will not grow as well. Removing large wayward roots also leaves unsightly scars on the visible roots. one reason for the foil wrap is to keep those roots growing close to the rock.
Fortunately, this escapee has not affected the roots inside the foil yet so when it is cut off the tree is still usable.
A few hours work and I have a small treasure trove of new pre bonsai Root over Rock tridents. They will be left buried here until I’m ready to pot them into individual grow pots to recover and begin the next stage of development.
If you have not seen the beginning of this process to develop root over rock bonsai using aluminium foil here’s a link to a previous post showing the earlier steps. http://shibuibonsai.com.au/?p=188
In an earlier post I mentioned that there is never just one way to grow bonsai. There are many different approaches that I use. In this post I’m hoping to present several different options for a tree like this. All of the different options would yield good bonsai. there’s never a single ‘right’ way to bonsai.
Here is another small, pot grown trident maple with lots of different possibilities.
Some beginners would be happy just to put a tree like this straight into a bonsai pot and call it bonsai. It has a trunk and some branches and it does look quite tree like but I can see future possibilities.
First step is always to check the roots. Visible surface roots (nebari) is very important in bonsai, especially in maple bonsai. Visible roots is a sign of age and stability. As trees grow the roots also expand so eventually the roots just under the surface start to get thick enough to show through the ground near the trunk. When we see this our mind knows that must be an old tree. Roots spreading in all directions give us the impression of stability and permanence so good surface roots helps make an impressive bonsai.
There is a good spread of larger roots there because this tree has already had its roots pruned a couple of times in past years to help form a spreading root system. You may also be able to see some thinner new roots that have grown this past season. They are a little higher than the older roots and mostly on one side of the trunk. If I wanted to lean this trunk over a bit further some of those new, higher roots would be great but I think the current trunk angle is good so I’m going to cut them off and use the existing thicker roots for the nebari on this one. The size, spread and angle of the surface roots is an important factor in deciding how to shape a tree. always check where the roots are and what the look like before starting on design.
Now we know the roots are Ok let’s check the top.
There are 3 strong, vertical leaders on this trunk. Maybe if I wanted to design a broom style tree I could keep several sub-trunks growing from the same place but leaving more than one growing close together will almost certainly lead to the trunk thickening significantly where they join. I try to remove multiples as soon as possible to keep good flowing taper.
That’s better but the tree now looks very tall and skinny. There’s lots of straight sections which seems a bit boring and there’s very little taper in the trunk. Taper is another important feature to give the impression of an older tree. Young trees grow up quickly to try to reach full height ahead of any competitors. At that stage they are tall and skinny and we recognise them as younger trees. As trees age the trunk becomes fatter but height doesn’t increase much and we tend to recognise that fatter trunks are older trees. In bonsai, we have several options to show viewers thick, old trunks. We can put the tree aside until it does have a thick trunk but we can also change the perspective. A shorter tree with the same sized trunk appears to be fatter than the same tree tall. I’m going to shorten this trident to give it the appearance of thicker trunk.
I usually look for a side branch to cut back to when pruning trees for bonsai. Here’s one option. Note that I’ve chosen a branch that’s growing back toward the base of the tree so I can eventually form more attractive bends in the trunk. This spot also gives me a side branch to start working with. What may seem to be a step backward is actually a bonsai step forward in the future development of this tree.
Although the new tree does look a little thicker with that reduction in height I’m still not happy with the result so I’m going to cut lower again.
Another temporary bonsai step backward in an attempt to give this tree a better future. This would be a fine spot to stop for now. Wiring that side branch up to become the new trunk gives me a really nice first curve to the future trunk. The step down in size gives the tree far better taper. Taper is another important aspect in simulating older looking trees. As trees age the lower parts tend to thicken far more than the upper parts so we see older trees with thicker trunks and thinner upper branches – taper. There is probably also an element of perspective involved. When we are at ground level, the trunk is close so it appears larger while upper branches are further away and therefore appear thinner due to perspective. Bonsai with good taper definitely appear to be older. Smoother transition from thicker to thin also helps our eyes travel up the trunk when viewing a tree so we try to avoid bulges and reverse taper in bonsai to enhance our view of the trunk and branches.
You might have noticed that I don’t have a desirable branch at that new bend in the trunk. Why didn’t I just chop the main trunk out and leave the new leader and the side branch? Whenever I’ve tried that the results are far from pleasing. The trunk appears to be a thick stump at the cut site. The problem just seems to get worse as the tree continues to grow and thicken. I’ve found this sort of angled cut a far better alternative. But what about a side branch at that bend? Even though there’s nothing there at the moment I know trident maples well enough to be confident that a number of new buds will grow near that cut. One of them will surely give me the branch I need. Another step back to set the stage for a better future.
However, I’m not finished with this tree yet. this option is Ok. It has reasonable taper and a good bend about 10 cm above the roots. With the oft quoted scale of the first branch about 1/3 of the at up a tree to look balance this little tree would probably grow into a really nice 30-40 cm tall bonsai. If that was my aim I’d put this tree aside now, pot it up into a larger pot and allow it to grow freely for another year to increase the trunk thickness.
That lower sub trunk has given me another option for this tree. I can see another step backward that will possibly give me an even better, smaller bonsai some time in the years to come.
This cut has given me even more powerful taper and a bend just 3cm above the roots. With this I will be able to develop a shohin sized bonsai 10-20 cm tall with excellent taper and good trunk bends. As a bonus, the new leader is already heading in the right direction so there’s no need to wire it at this stage. note that I’ve pruned back the new leader to where there’s a couple of sets of buds on short internodes. Short internodes are even more vital for smaller sized bonsai so I always remove shoots with long internodes and develop my trees from shoots and branches with short internodes. The shorter the better.
This tree will be root pruned quite hard this winter or spring to further enhance those surface roots and given fresh potting mix to accelerate growth next summer. A larger pot would give increased growth but there’s a chance of it growing too much and losing the current good points. Slower development takes longer but usually gives me superior results in the end.
Another year or 2 should see some trunks with both taper and attractive bends. Maybe they even have some shoots in the right places for branching.
Take a closer look at some of the issues that need dealing with.
The first branch has died back a bit and the remaining shoots are crowded and growing at awkward angles. Maybe it would be possible to wire these and bend them into acceptable positions but the outer ones look a bit rigid to me so I’m just going to prune back to a thinner part that I can bend with wire. Pruning also puts valuable taper and good bends into the branch.
Further up the trunk there are 2 upright branches, both trying to be the apex of this tree. there are also those strong upright new shoots that grew last summer. Note the long internodes.
Either of the leaders could give a good overall tree shape but I’ll keep the longest one to give the tree more movement.
Those long internodes are no use on a small bonsai. remove all shoots with long internodes completely if you don’t need a branch in that place or back to the base if you would like a branch there. Fingers crossed that the next shoots to grow will not be quite so vigorous. This time I am lucky. there are already smaller shoots with shorter internodes growing below those big vertical ones. just right as the basis for a future branch so I’ve pruned the strong vertical ones off completely. (see final photo)
There are more shoots with long internodes toward the top of the tree. (blue lines) New shoots can only ever grow from the nodes so If I try to make branches out of these shoots they won’t have many side shoots. Remove all long internodes, even if you do want a branch at that point.
Now on to the apex.
I’ve removed the right shoot at the top mainly because I think movement to the left looks better. the left shoot is also a bit thinner so taper is enhanced.
A little wiring has been used this time to help position the remaining branches. A couple have been bent down closer to horizontal and others have been rotated so the smaller twigs are now horizontal as the basis for future branch ‘pads’
This time the trees are another year older. You may find starter stock like these in the bonsai section of nurseries. If you are intending to grow larger bonsai or really fat trunks your trees should be planted in the ground or large grow pots by now. I’m aiming at smaller sized bonsai with these. At this stage the possibilities start to magnify and different growers will take different routs to produce bonsai from this point.
This one has reasonably attractive bends in the trunk and a few small branches to choose from. Some beginners would be happy to put a tree like this straight into a bonsai pot. That’s fine if you want to but I can see plenty of improvements I’d like to make for the long term future of this as bonsai.
First I’m checking the surface roots. Nebari, or visible surface roots, is really important to show age and stability in a maple bonsai. I want to have good, strong roots evenly spread all round the trunk if possible.
The roots are a little lower on one side. If I tilt this tree a bit the current roots will all be level – a far better view. Fortunately this tilt helps bring the top of the tree above the base and actually improves the flow of the trunk.
There is very little taper in this tree. A good maple bonsai is much thicker at the base and tapers gradually right through to the top of the tree. Pruning is the quickest way to introduce taper into your bonsai, removing thicker parts and keeping thinner sections as new leaders. The section marked in blue below is also very straight so doesn’t fit well with the curves in the lower trunk.
Pruning away the problems will leave me with a far better skeleton.
I’ve removed that straight section completely to continue the curves then cut out the top of the tree at a convenient smaller side branch which will now become the new leader giving the tree some more bends as well as taper almost instantly. Now that the tree is shorter it also appears to be much thicker.
I’ve also decided to wire those 2 branches now while they are still flexible enough to bend easily. There’s still a few years of growing and development ahead. the extra, unwired branches are probably not part of the final design but won’t hurt in the short term and will probably even help the trunk to thicken a bit more. I’m also hoping for some more shoots to pop out of the trunk next spring after removing this much from the top of the tree. maybe some of those new shoots will be in good places to add more branches to the tree.
In the last post we looked at one way to start working with raw seedlings. This time the trees are a year more advanced. Again, the following is just one possible way to move these small trees toward better bonsai.
Here are 3 typical 2 year old trident maples that were root pruned and cut down last winter.
The tree on the left has some really good trunk movement. Most of those bends would probably disappear if this one was grown on to thicken the trunk. I think it will make a better small bonsai. The others could grow as either small or larger trees.
My initial aim with young tridents is to get good nebari – we’ll look at that later – then to get good trunk taper and some bends. Wiring is not the only way to put bends into trees. Pruning seems to make much more natural looking bends so look for places to prune that leaves the best bends in the tree.
Pruning is also the best way to introduce taper into young trees that have little. Look for places where the trunks fork into a thick and a thin leader or branch. Cut off the thicker one and you’re left with a better tapered tree.
Here are the same trees after pruning for movement and taper. Note that I have not tried to keep branches at this stage. For the first few years everything is about developing a good trunk and better roots.
These trees could now be root pruned again and potted on into larger containers or into the garden to grow even faster. Growth in containers may be a little slower but I find that I have much better control over the development, especially in smaller sized bonsai.
Next time we’ll skip ahead another year to see how these trees might develop.
It is no wonder that newer bonsai growers are a bit confused and have to post so many online questions about dealing with relatively undeveloped stock. That’s what you have to work with but experienced growers only ever post and talk about techniques for working with well established bonsai.
So here’s some ideas and technique that I use on much younger trident maples. Please be aware that young trees like these can be developed into almost anything and different techniques could be used depending on the desired outcome.
Starting with really young seedlings:
These are typical 1 year old trident maple seedlings that I’ve just dug out of our garden so have never been trimmed top or roots. Please ignore the leaves on the left hand seedling. these were dug a little earlier than normal for this post. Usually tridents are root pruned while they are completely dormant (July – September here)
My first step is always the roots. Good nebari is important for bonsai, even more important in maples. Many trees are far more tolerant of root pruning than we give credit for. Tridents are among the hardier species so roots can be trimmed quite hard. Try to cut strong down roots just below a good layer of lateral roots that will form your future nebari. If there are few laterals just cut the main root a little below soil level and most trident seedlings will respond with plenty of new lateral roots. Luckily these seedlings already had quite good roots. you may be able to pick up where I’ve also removed a few higher roots which were growing just on one side.
Finally I usually prune the tops. This will force several new shoots next year which should give me more choices for trunk movement and for creating taper.
Now just pot your seedlings up in your preferred bonsai mix or a good commercial potting mix. These little sticks could go into either 11cm or 15 cm pots.
I understand that not everyone has old, well developed bonsai so while it is nice to see the sort of pruning I showed in the last post, many of you are just starting out with much younger trees.
I picked out this trident maple because the trunk has good movement right down low. I think it has potential to produce a good bonsai.
As it is currently it is not particularly good. Lower trunk has some taper and attractive movement (blue section below) but there is little taper above the green line. The upper trunk sections are quite straight (red section) and do not complement the bends down lower.
It may seem drastic to many beginners but sometimes the best way to move forward is to go back a bit so I’ve reduced the trunk to remove the problem areas.
I’ve pruned this one just above some small branches that have good potential to become new leaders and/or branches.
I have not decided which of those will be the new trunk. The one toward the left will bring the trunk back toward the base of the tree which may be good for balance but the one toward the front will bring the trunk line slightly forward and probably continue the leaning trunk line. I’ll leave them all to grow a bit first and see what starts to look good before removing the spare ones.
Some will be wondering why I haven’t just left the whole tree intact because this tree does need to grow and thicken and pruning is generally thought to slow growth. In my opinion, fast growth is not the be all and end all of bonsai. I’m actually aiming at a smaller tree, probably in the shohin size range – under 20 cm tall so a trunk maybe 3 cm diameter will be adequate. The current character of the lower trunk is likely to disappear with rapid trunk thickening. Allowing the whole trunk to thicken will also mean I’ll end up with a much larger cut when I eventually prune the trunk (those straight sections will still not look good even on a thicker trunk). I’m also hoping for a more elegant, flowing tree to take advantage of that leaning lower trunk so I am more than happy to grow this one just a bit slower to avoid large scars and thickened sections.