Trident Maple Root prune

[Raging Bull]

Hi,
I need a bit of advice on root pruning a trident maple. I acquired the tree as a seedling from shibui two years ago in a batch, most of which I planted as a forest which will also need to be pruned an root pruned in preparation for planting into a pot. That's still an upcoming job for this winter. It seems like we've had some pretty cold weather this winter, cold for Queensland anyway, but the buds on a lot of my deciduous trees are already swelling, even though last summer's leaves are still on the trees.
On receipt this tree had the tap root cut off and was then planted on top of an old CD which has given it a nice shallow even spread of roots. So I've given this trident a trunk chop and reduced the roots considerably. My question to those in the know is, Should I thin out and cut more of the roots off or repot this tree as in the last picture?

[Ryceman3]

Hi RB,
I feel like you can cut back harder if you are comfortable with it, maybe another cm or two on the last picture. Even then I feel like that would be conservative but I only have experience in my climate, Melbourne, so take that advice on notice.
There's a good spread of roots 360deg around the trunk which is handy, I'd be looking to get an even layer - it looks like there are roots stacked on top of other roots so I'd be trying to cut back to one level if possible ... still maintaining a radial spread ideally.
Also, I would look to have the nebari not too flat (i.e: I try to avoid having the roots spread from the trunk at a 90deg angle, a bit more obtuse than that) and then plunging into the soil so that it looks more like it is "grabs" on more than spreads over it. I hope that makes sense, and it is just my preference anyway, I think it makes the nebari look more authentic.
Hope that helps, you've got some nice root growth so if your not comfortable cutting further I'm sure it will be fine as is for now.
It's a nice base, good luck with it!

[MJL]

Hi RB,
There's a good spread of roots 360deg around the trunk which is handy, I'd be looking to get an even layer - it looks like there are roots stacked on top of other roots so I'd be trying to cut back to one level if possible ... still maintaining a radial spread ideally.
Also, I would look to have the nebari not too flat (i.e: I try to avoid having the roots spread from the trunk at a 90deg angle, a bit more obtuse than that) and then plunging into the soil so that it looks more like it is "grabs" on more than spreads over it. I think it makes the nebari look more authentic.

Hey RB - excellent start I reckon - be very happy with what you've got already. I just quoted R3 because he just 'meatloafed' me .... he - "Took the words right out of my mouth" I won't say the next line because that's just too weird.

Cheers,

Mark

[Matthew]

Yes you could defiantly reduce the root ball more . That way you'll get secondary roots closer in . Seems to have a good even root spread . Neil does some nice work

[shibui]

I would definitely shorten all those roots by about half at this stage. New roots nearly all come from the cut ends so if you want ramification close to the trunk that's where you need to cut. There is no danger cutting trident roots that short and lots to be gained.

I also think Ryceman is correct about the layers of roots. A single thin layer will be far better than roots at all depths. those upper roots may look benign at the moment but if they stay for another year the trunk will be substantially thicker there than below so you will have lost the opportunity to remove them if the lower roots are better. I think you have 2 choices - either cut through the main trunk just below those upper roots OR remove the upper roots down to where there is a good spread of the lower roots. I generally use the first if I can see any reverse taper has already occurred and the latter if there is a good layer of lower roots and no reverse taper in that area. Even if you have to remove all the lower roots to preserve trunk taper that will not harm a tree of this age. After a year I generally see lots of new roots growing from the trunk close to the cut so even when I've only left a few roots the nebari generally fills out quickly because the tree has been forced to grow plenty of new roots as a result of the drastic reduction.

That's what I would do. Whether you want to go that hard is up to you. In hindsight you could probably have made the original root cut a little higher to reduce the higher and lower roots you have produced or have those upper roots grown since then? tridents are notorious for popping new roots out of the trunk just under the surface so trees that are planted a bit deep end up with new surface roots above the originals.

Nice job on the nebari so far. I'm actually impressed with those results from a CD.

[Raging Bull]

Hi, thanks for all the quick replies, it's made my decision a lot easier. I've had another closer look at the trunk between the upper and lower roots and there is no reverse taper. The upper roots all grew out of the trunk down into the ground and the lower roots grew from where the tap root was cut off. The upper roots are well distributed all around the tree and angle downward whereas the lower ones all leave the trunk at 90 degrees. For these reasons I'll remove the lower roots and use the upper ones when I repot the tree tomorrow. When done I'll post a pic of the result.
Cheers, Frank

[Raging Bull]

Hi, Well tomorrow has been and gone and I've taken the plunge. I removed the majority of the roots and shortend the main root below the remaining roots. The pictures tell the story. Then I repotted it and now I'll wait for spring and hope for the best. Did the same with several other seedlings today also. Still procrastinating with the forest planting tho', I keep telling myself I'll need most of a whole day for that and I'll need to make some sketches and plans first. But thats another story.
Cheers, Frank.

[MJL]

Well played sir! Gee this is a funny hobby - where some may see a stick in a pot, others see potential. I see the latter in this little tree. Now off to golf to wreck a good walk in the park.

[Raging Bull]

Thanks MJL, I don't play golf but will go for a surf.
Cheers, Frank.