AusBonsai

Generally when root pruning we are told to only take off one third of the root mass, looks like you've taken quite a bit more. Is this because tridents are quite hardy?

This appears to be another of the half truths that have become entrenched. I have had plenty of time to try out different techniques and have discovered that very little of what has been handed down is actually hard facts.

Most species can cope with losing far more roots than 1/3. I grow lots of cuttings. I can plant a stick with NO roots and most of them survive. When you go to the nursery at this time of year they will sell you bare rooted fruit trees and roses. Most of these have had well over 1/2 of the original roots removed but have almost 100% survival so why should bonsai be any different?

Cutting roots hard at times can improve the nebari and also produce a root system that will adapt to the pot far better. In actual fact I have left quite a lot of roots on this maple. Other trees that can tolerate radical root removal are: ficus, Gingko, Swamp cypress, Dawn redwood, azalea and there are lots more. I usually leave a little more root on Japanese maples and most conifers.

shibui wrote:

Generally when root pruning we are told to only take off one third of the root mass, looks like you've taken quite a bit more. Is this because tridents are quite hardy?

This appears to be another of the half truths that have become entrenched. I have had plenty of time to try out different techniques and have discovered that very little of what has been handed down is actually hard facts.

Most species can cope with losing far more roots than 1/3. I grow lots of cuttings. I can plant a stick with NO roots and most of them survive. When you go to the nursery at this time of year they will sell you bare rooted fruit trees and roses. Most of these have had well over 1/2 of the original roots removed but have almost 100% survival so why should bonsai be any different?

Cutting roots hard at times can improve the nebari and also produce a root system that will adapt to the pot far better. In actual fact I have left quite a lot of roots on this maple. Other trees that can tolerate radical root removal are: ficus, Gingko, Swamp cypress, Dawn redwood, azalea and there are lots more. I usually leave a little more root on Japanese maples and most conifers.

I agree. Some of the generic advice from the 70's / 80's is not up to scratch due to current care and knowledge. You can also add Casuarina and Bougainvillea to that list too. I have actually cut up to 70-80% of roots of a lot of species in these genus during late Spring / Summer and had no problems at all. From my experience you can also add selective Eucalyptus and Melaleuca to that too: in particular E. robusta, E. saligna and M. quinquinervia, M. halmaturorum. And obviously weeds like Lantana etc. Just make sure they are in good health before you do.

I actually repotted and took off 50% of the roots from Eucalyptus robusta in the heart of winter due to some root rot and it didn't blink. I cut back a bit of foliage, and ... the remaining foliage drooped a little for a week, then it recovered fully. Very hardy Eucs, the above mentioned.

shibui wrote:Most species can cope with losing far more roots than 1/3.

Couldnt agree more Neil. I do it regularly also. Should pop that little trident to the right hand side of the pot for balance? while you can.

My understanding of the 1/3 rule comes from a book written in the 50's instructing Americans who had bought home Bonsai from Japan on how to look after them. It is for established Bonsai in Bonsai pots. You removed the outer 1/3 of roots, including the underside, the soil from the next third, including the underside, then about 1/3 to 1/2 of the remaining soil in wedge shapes like pieces of pie. This was based on the tree going into the same pot. If going into a different size it would then be based on the size pot it was going to. That is, less roots removed if the tree was going into a large pot and more if going into a smaller.

Obviously trees in development would be different and aren't really talked about in the book, but I wonder how much of the accepted wisdom is based on ideas of maintaining Bonsai for the masses and become entrenched as hard rules.

Do people when they repot established Bonsai work on about 1/3 of the roots? And what above removing older soil in wedges?

BTW, the book also describes soil based mixes made of graded clays and loams, which I doubt anyone would use anymore. Even organic based mixes which it seems people are moving away from are still soilless.

Should pop that little trident to the right hand side of the pot for balance? while you can.

This configuration is where I would normally plant Bodhi. I think it looks odd set at the right end of the pot. I'll get a photo and see what people think.

Do people when they repot established Bonsai work on about 1/3 of the roots? And what above removing older soil in wedges?

Quite a few of my older trees have large plates of solid wood - fused roots and base of the trunk under the soil. Only 1/2 - 1/3 of what is below soil level is feeder roots and potting mix so do we measure the fine roots or everything below soil level? I still think I remove more than half of the fine roots of all my older bonsai so I suppose it depends how you define 'roots'
I try to remove as much of the older mix from the roots when repotting. Usually it can be shaken or poked out with a stick or root hook, sometimes washed out with the hose but rarely cut out in wedges.

Hi Neil,
What is the best time to transplant maples for you? End of August?
And which other month you have transplanted them successfully?
Thank you in advance.

Tridents are really hardy here Neli. I transplant tridents any time they have no leaves so for me that is May-August. I have also re-potted a trident in full leaf in summer for 2 years running without any problem viewtopic.php?f=12&t=18983&hilit=+trident+summer
And Grant has also repotted a more mature trident in summer in Canberra.
I suspect you can transplant trident at any time of year.

Thank you Neil.
I have to transplant too many tridents this year and have to do some travels, to do some demos abroad. I shall start them sooner.

This little trident has done it again this autumn. As you can see above it was repotted last winter but the roots have pushed it way out of the pot in just the past few weeks. I'm wondering whether it is a characteristic of this individual tree or maybe this pot has something that encourages really strong root growth?

Wow,very healthy tree and with a root system like that no wonder,are others behaving like this?

I like to see this indicating feeding regime on song,can understand as a nurseryman with many trees probably not there best look,(just mildly)lol.
Wondering does it sit in the same place each season and what is the fert/roid programme ?,very interesting and unusual...Neil

cheers Anthony

I have a some that do similar things as well
1 trident in particular planted in a grow pot sends masses of roots thru the holes in the orchid pot and creates a mat underneath.
if it did not have lots of holes to escape thru, it would push out the top too.

Ken

I grow a few tridents an have noticed a range of different traits between each. A couple have a tendency to form swallow flapping woody bases but have course ramification while others roots develop much more slowly yet have fine branching and better ramification. I certainly believe that there are different varieties and or seed strains and I am interested to propagate from a few to test this theory.

Eg. Trunk is thin but the root base is flared and woody. This tree has course canopy growth though.

Nice roots on that one Jow

Maybe graft on some better foliage?

Ken

I also have a trident that has produced a massive swollen base without any assistance from me. It also has very poor top ramification and is frustrating to try to build good branches on. I have noticed that it never produces the red new leaves that most tridents have - new shoots are just plain green leaved.

I have considered grafting the normal easy ramifying top onto the large base roots Ken, but my first attempt failed and I have not had time to try again.