Okiyama Technique ?

I have been reading old paper copies of our club's newsletter for reprise articles. This article caught my attention, "Okiyama Technique" written by Roy W. Hauser of the Okiyama School of Bonsai in Wilderville, Oregon.

The article discusses a" technique to rapidly develop the trunk and upper root system ".... "it duplicates the natural process of a tree that grows on a steep forest bank." There is a lengthy discussion about how to reproduce the erosion of soil around the roots and base of the trunk of a well established bonsai. The plant must be in a plastic nursery pot and the grower cuts the pot to the soil level with further cuts to progressively erode the soil.

Has anyone used this technique and was it successful?

Best regards,
Norma

Yes. It is easy and it works well. Doesn't need to be a plastic pot, but removing top soil little by little over time, exposing top roots and base of the trunk for sun and air thickens these, because the bark will expand protecting the exposed areas.

Regards
Morten

If your tree has a shallow root system, it seems that it wouldnt take very long and you would have no roots in the dirt at all. Is this just for creating exposed root styles? Later on after you have the thickness you want and your going to display it, do you add the dirt back on to make it look appropriate?

Thanks Morten, I'm happy this is a viable technique but the use of the plastic pot must assume you will remove, in the end, an inch (2.5cm) or more top soil during the course of a month or more.


bucknbonsai, The article talks about removing some roots during the course of the soil removal. I probably wouldn't attempt this experiment with a shallow root system and a transplant to a plastic pot should proceed this technique by at least a year.

The article does recommend replacing soil once you've achieved results and it also suggests using the process during the cooler months to minimize shock.

Norma

You know I've always read that to thicken surface roots you should bury them deeply, but in order to get mature bark on surface roots yes you would want to expose them to the elements.
-Jay

Jay, beat me to it - was going to post the same thing!

I've read numerous places that covering the surface roots will encourage them to thicken faster. I've also read numerous places that when collecting trees, those that are growing with the trunks obscured by grasses and other low vegetation will often have the oldest-looking bark. I don't quite understand the reasoning for that, but I'm pretty sure I saw that comment many times in a book by Nick Lenz. Have also read about wrapping trunks in damp sphagnum as a way to encourage bark to develop or age.

So what is this technique trying to accomplish? How does it relate to these other methods?

Chris