Growing JBP's in the ground

Page 113 of the Masters Series on pines depicts a photo of pine that was started from seed three years ago. For the first two years the seedling was grown in the ground to thicken the trunk. In the third spring it was put in a training pot and was fertilized with high nitrogen every two weeks. Height 10". The trunk dia. in the photo appears to be about 6". The book was first published in 2005. I assume that the seedling was one year old and might have been ground planted in 1980 or earlier with the first edition printed in 2005. If that seedling grew for two years in the ground and attained a 6" trunk, I’d like to obtain the same results. I believe I am missing something regarding this tree’s growth and the narrative in the book is not correct. Regardless, what is the correct way to grow JBP seedlings in the ground? How is the ground prepared? Is the seedling bent before planting? How long should they be left in the ground? Any other details would be beneficial for any of us attempting ground growth.

Fun question. I just checked the book and the original BT#2 but am now curious to check the dates in the original article in Kindai Bonsai. I’d be very surprised if this tree is only 3 years old.

My understanding is that pines are typically planted in the ground after a few years of container growth. How the soil is prepared depends on the soil. The most important thing is that the soil drains well.

Some people place tile/stone/wood under each tree to prevent roots from growing downward. Some people dig up pines every few years to work on the roots, wire, and cutback unnecessary growth. Others leave the trees in the ground for years.

The most important thing when growing pines in the ground is getting the trunk and roots right. The basic process is no different than it is for container-grown pines, though caution must be taken as pines can grow very fast in the ground.

Here are some photos from the biggest pine growing area in Japan:

Were I ground-growing pines, I’d aim to follow a process similar to the process outlined starting on page 140 of the same pine book (originally published in issue 20 of BT).

When i look at the picture on the top right of page 113 (Masters Series Pines) i agree it is unclear as to the size of the trunk caliper. It could be anywhere from 2-3 inches rather than 6 inches. Also it is unclear as to how the height of the tree was measured. Is it the topmost candle or the developing apex? I do know that some of the original translations in Bonsai Today can be misleading. For example the timing on seed development and when to cut the JBP seedling for radial root development. The translation indicates that one should cut when the stem turns violet. From experience i can assure that not all the stems will turn violet before they should be cut. (Page 143 same publication as above)
A longer time frame make more sense to me as most of the literature seems to document an eight to ten year frame for similar pine growth. For your reference the article Sowing the seeds ( page 68 Bonsai Focus #134/157 May-June 2015) describes the required steps and accompanying techniques from year one through year ten. I think this article clearly address’s many of your questions. Japanese Black Pines of a similar caliper ( 3"-4" ) that i have purchased from a very reputable grower in the state of Oregon took approximately eight years in the ground. I was told they were planted in the ground when purchased as two to three year old seedlings.
This also matches with the JBP seedlings that i am currently growing. Those in the ground for the last two years have reached a trunk size of approximately 3/4 ". Please keep in mind that i followed the root cutting technique for developing radial roots which sets back the growth pattern initially. They were planted in colanders, with boon mix and placed in pumice beds approximately 16 months after germination. Germinated in January and then kept in the green house over the first winter. Hope these comments are helpful, i know i was frustrated when i realised that the information could be incomplete or misleading. Older and or wiser idividuals explained to me that the translation in some of the early articles left something to be desired.

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With respect to “river sand” mentioned in the Kinashi District, the photos appear to show pines being grown in pots with aquarium sized pebbles or in the ground with similar pebbles. Would it therefore be appropriate for one to try growing JBP’s in pots or in the ground with only aquarium pebbles as the only “soil” item or should the ground or pot also contain APL and some organic material? I have eight, three to five year old pines growing in APL colander type containers that I can repot in February in pots or directly in the ground using only aquarium pebbles if this would be considered as a good experiment?

I think it’d be great to experiment with growing pines in straight DG without any akadama, pumice or lava. As when using any inorganic mix, organic fertilizer will be needed to help the trees get the nutrients they need.

One thing that makes pure river sand appropriate for Shikoku pines is that summers are hot, humid and rainy. Cooler or drier areas typically benefit from the increased water retention of akadama, pumice and lava.