Japanese Maple Nebari Development

Repotting is different than typical bonsai styling because the amount of time one gets to see and work on roots is so short and infrequent; quite unlike the rest of the tree that we contemplate each day.

However, root work will make or break a bonsai.   For that reason, and the fact that I have a horrible memory, I make it a point to photograph my bonsai as I work on the roots.  This allows me to make a plan, and (more importantly) helps me remember that plan during the next repotting session!

Here is a quick look at developing a Japanese Maple’s nebari, over the last 3 repottings.

First, 2008 (third repotting)

Looking back at this, 4 years later, I would have cut each of the heavy roots back at least as far as I cut the left two roots shown above.  They are thickening well, but it would have been better to get the ramification closer to the trunk.  I also would have removed the lower root on the right (at the 5:00 position) , where it’s fused to the root above.  Now it’s become a feature.

2010 (fourth repotting)

Combed out, trimmed back

Washed out, and further reduced

Close-up.  Note the root at the 7:00 position was shortened in ’09, and new roots are growing well from the cut.  Rooting powder was placed on cuts to encourage new roots to grow in the gap.  They did not appear.

2011 (fifth repotting)

This year, the repotting was less invasive (mostly due to the fact it was done as a demo), but the roots were still combed out radially and shortened.  Tertiary roots are starting to thicken.  See why I wish I’d have cut the main roots back shorter?

2012 (sixth repotting)


Combed out and shortened.

Hosed, combed and shortened further.  Notice the tertiary roots are thickening and maturing.

Close-up of roots, some thick roots were removed, just like branches to keep movement and taper.

Because no heavy roots remain, the fine roots are arranged in radial direction, then bamboo sticks are laid across the fine roots, and anchor wires are tied over the sticks to hold everything down.  The gap in the center is still troubling.  Fertilizer cakes were packed into the gaps right up to the trunk, and fine feeder roots did develop there, but they didn’t originate from the location.  The goal is to either have the existing thick roots finally fuse, or continue working to develop fine roots that will knit together over time.

After.  The tree was potted slightly higher this time to start to expose the tertiary roots and allow them to mature and thicken.

Thanks for looking!

Wooden boxes and collected material

In the spring of 2010, a collecting trip to South Dakota produced some trees with potential. While its important to collect the root system as completely as possible (intact is ideal), aftercare is the key to nursing a collected tree back to health. Seven of the trees collected were planted in the ground to recover, and 2 made it. 10 were planted in pots, and 9 survived.

Of the 10 trees planted in containers, most were planted in Anderson flats, and the voids were largely filled with chunks of styrofoam, so the volume of new soil added was minimal. Several trees were planted in wooden boxes as well. Those in wooden boxes seemed to be more vigorous and in the second season became pretty thirsty trees.

While the weather has been mild here, it is still too early to do root work and repotting. However, the wooden box finally gave up the ghost yesterday, and I needed to shift it to a more stable pot. The original box was the right length and width, but it was about 15″ deep, so we made a false bottom with blocks of styrofoam, and only the top half of the box actually contained soil. After 2 years in the sunshine, the wood was warping and soil was leaking out of all four corners.

Here are some photos of the repotting.







This will be its third growing season after repotting, and it will be allowed to grow freely at least this year and likely next year as well before any work is done on the top.