How To Root-Prune?
How To Root-Prune?
Root pruning is one of the most important aspect of bonsai training. perhaps because of the fact that roots are not visible when looking at a bonsai, it is often overlooked, ignored, and therefore poorly done.
Similar to branch pruning, we are aiming to create taper in the roots as well. good nebari(surface roots and flare) is very desirable because of the appearance of stability and age it creates.
Here we’d like to share with you how we perform root pruning on a number of trees. let’s start with TRIDENT MAPLE.
This trident maple in the video was grown from seed 4 years ago. it spent its first year in the ground to get a bit of thickness then the next 3 years in a pot to develop its nebari. it has been root pruned as shown in the video every year. the nebari is now twice the width of the trunk. it will continue to be root pruned in the same manner as long as it is in our care.
After root pruning
After washing away the potting mix(1)
After washing away the potting mix (2). All the thicker roots will be pruned next season
Viewed from the underside of the tree
So, what did i cut off?
- Every single root, large and small, growing straight down.
- Any root that grows ABOVE the chosen line of the surface roots.
- Any root that crosses the radial emerging roots from the trunk.
- Perhaps the most important, but it was not performed this time(the larger roots of what was left, still small enough to stay), was to prune off any thick root right back ,flush to the nebari. by doing this encourages ONLY fine feeder roots are left to grow from the nebari and they help to PULL the nebari out radially.
Here is how it is potted up.
It will then be placed in a position sheltered from wind until new growth begins.
This method of root pruning can be used on most vigorous deciduous species(maples, elms, zelkova, liquidamber……etc) and it can be done from early winter to late winter.
JAPANESE MAPLE
Before any work
After branch pruning and wiring
This japanese maple was grown from nursery stock by a friend about 20 years ago. being a nursery stock, there was no attention paid to the nebari, hence the big vertical roots. however, as the tree ages, it is becoming a feature for the tree(an exposed root style). the videos show how it was root pruned and potted up.
This maple was not root pruned as hard as the younger trident maple, not because it is older, but because i am not aiming for the perfact nebari with this tree(being somewhat of an exposed root style).