Field grown trident

Shibui

Imperial Masterpiece
Messages
7,545
Reaction score
15,222
Location
Yackandandah, Australia
USDA Zone
9?
I'm aware that I use some different practices for field grown trees for bonsai. Just though some Bonsai nutters might be interested in a quick pictorial explanation of Shibui Bonsai field growing for trident maple.
Remember there's always other possible ways to do this but after nearly 30 years of growing tridents for bonsai these are some of the techniques that work for me.

This trident is around 5 years from seed. It's been in the ground for the last 3 years.

I start by digging round the tree to cut the roots. Annual root pruning has produced masses of finer roots rather than a few thick ones so digging is easy.
CH130003.JPG

Shake, scrape off as much soil as possible without damaging roots too much. I know I'm going to shorten the roots quite a lot so breaking a few outer ones doesn't concern me here.
CH130005.JPG
Take a closer look at the roots. The clusters of finer roots are growing from the ends of roots that were cut last winter. I find that more than 90% of new roots after root pruning come from the cut ends like this so it makes sense to me to chop roots short in order to get new roots where they will be needed. The tree has had similar root chops each winter, just laving short stubs of new sections of root each time.

You've probably also noted the flared trunk base and nebari. Lots of roots from previous root pruning have thickened and fused into the flared base.


Here's another technique I often use to get enhanced nebari on tridents.
CH130006.JPG
That's a piece of flat aluminium under there. I start these by threading a seedling through a hole in the middle of the sheet metal. As the trunk thickens circulation is restricted and the tree responds by growing new roots just above the restriction. Those new roots can only grow horizontally out over the flat sheet so I get a flat, spreading root base without work.
By this stage the metal plate has done its work so I can trim the roots further and remove it.
CH130011.JPGCH130007.JPG

Now onto the top which has already had a rough prune to make the tree easier to handle.
CH130008.JPG
Previous pruning has promoted lots of branches/trunks. Each of those contributes to trunk thickening but unlike a single trunk these trunks thicken at different places which promotes more taper. In addition instead of one single, large cut after pruning that's going to take many years to heal, I have lots of smaller ones that heal much quicker.
The extra trunks also give me more options to prune for trunk taper and enhanced bends.
CH130009.JPGCH130012.JPGCH130013.JPG
I've left a few branch stumps on the trunk. Most will be removed in years to come as most are way too thick for good branch bases and/or the angles are poor but for the coming year shoots that will emerge will help grow new roots and heal the chops I've made this time.

Final step for now is to heel the tree back into the ground until I'm ready to decide whether to pot it up for sale or replant for another year's growth.
CH130015.JPG
They'll sit quite happily like this for a couple of months over winter, at least until the new roots start to form just before bud burst.
 

Rivian

Chumono
Messages
871
Reaction score
715
Location
DE
USDA Zone
6
Id be a bit concerned about inverse taper
Also might have bitten back some of the branches completely, not leaving stumps
But I have no personal experience with fieldgrowing tridents yet
 
Top Bottom