Losing Trees: Corkbark Japanese Black Pine, ‘Kyokko Yatsabusa’

Here is a post from 4 years ago when the tree looked good.

https://nebaribonsai.wordpress.com/2019/09/21/fall-cleanup-on-a-kyoto-yatsabusa-corkbark-jbp/

The tree has a weak root system, and I ended up planting it in the ground to strengthen it for a few years. When we moved in December, I stuck it in a pot. It wasn’t much healthier, and the lack of roots was alarming.

In March, buds were actually swelling, and it made it through winter, so I figured I’d at least give it a fighting chance.

The lowest branch did die, but it was a debatable feature that made the decision easy.

Unpotted, check out all those roots.

Using a few screws and chopsticks to create some anchor points, I managed to secure the tree to the pot.

Notice the deep drainage layer of medium-grain akadama. The layer of soil used in the zone where the roots are is a more retentive mix of akadama, pumice, and lava. The top layer included more Kiriyu sand so the top third isn’t as retentive since it has no roots.

Repotting completed.

Next up, dead stuff and old needles removed, and new needles reduced to 12-15 pairs around extending candles. I also removed weak shoots and excessively strong shoots and removed all old wire.

Finally a couple pieces of wire to gently moved a couple shoots into position.

One more shot with a deeper background.

Spring work done, now I hope and feed heavily for some good growth. Unfortunately, by mid April, it was clear that the tree wasn’t able to survive the move. As soon as we had some sunny warm days, the green foliage got dull, then gray, and finally the straw-color that is hard to look at on the bench. RIP.

A telltale sign is when the soil stays wet, and the trunk doesn’t show any signs of wicking.

Parting shot of that killer bark.

Shimpaku Rework

After showing this one at Nationals in 2016, I kept in pretty good condition for the next few years to show it in several shows.

When I repotted it in 2022, I used some soil that apparently had some bike chain cleaner spilled onto it. I noticed it appeared a little wet, but when I found the tipped over bottle above the bags of pumice and lava, I thought it could be a problem. It was.

So, I let it grow a little wild hoping it would recover. Last year, to add insult to injury, it got spider mites and the whole left side of tree went gray.

This spring, I repotted it to replace most of the soil.

Then, unwired: every branch was wired and starting to bite in. I cleaned the live veins by removing the old bark, and cleaned up the dead wood, scrubbing off algae and adding a fresh coat of lime sulfur.

Corkbark Japanese Black Pine, ‘Taihei’

Here is another corker that I’ve neglected, though it’s been in a pot and managed to stay healthier than the Kyokko Yatsabusa. It was last repotted in 2019, and this spring’s work was pretty straight forward.

Starting point, notice how full it is, and some shoots are very strong. The soil is covered with moss and weeds. Without cutting strong shoots, they’ll overpower the weaker ones and the growth will get leggy. Without pulling old needles, the growth will weaken on the interior and it exacerbates the imbalance between strong and weak growth.

This shoot has a strong bud at the tip, and a smaller bud at the base. Since it’s near the apex and at the exterior of the tree, I’ll remove the stronger shoot in favor of the weaker.

Cut

Smaller bud remains. It will strengthen, and will provide some new growth closer to the trunk.

After balancing the tree as demonstrated above, and pulling needles to ensure sunlight can penetrate to the interior.

Old soil scraped away down an inch or so, then replaced with fresh and worked in with a chopstick. Next year, it will probably be time for a proper repotting.

Finishished

And back on the bench.