Advertisement

Daisugi – Japan’s Forestry Technique That Produces High-Grade Lumber Without Cutting Down Trees

by DailyHealthPost Editorial

Most of us have heard about bonsai trees but there’s another ancient Japanese forestry technique that’s arguably more fascinating, beautiful, and even useful than bonsai and that’s daisugi.

Advertisement

Daisugi works on a similar principle to bonsai in that it involves heavy pruning of trees to “guide” their growth. But while in bonsai that’s used to keep trees in a miniature size so they can be grown indoors as large flowers, the goal of daisugi is very different.

With daisugi, the forester or arborists will prune the tree – traditionally Japanese cedar trees – so heavily from a certain point, that instead of growing multiple branches in every direction it only grows a single or a few tall branches going straight up.

Advertisement

The tree is first grown to its large “adult” size, of course, and it’s allowed multiple branches in its lower half. However, going upward, it’s pruned so that only 100% vertical branches are grown. The end result looks both amusing and captivating and daisugi is a treasured part of Japanese arboriculture. 

Why is daisugi done, what is its benefit?

Originally, the daisugi technique was developed around the 14th century in feudal Japan. It was done because the island country had a much higher demand for high-quality lumber but not many wide forest regions. Japan’s several islands are mostly full of high mountains so it couldn’t supply the lumber its people required. 

Daisugi fixed that problem by allowing the Japanese people to get quality lumber without chopping off their forests. Because with this technique you get lots of very tall, very straight, and very thick branches, the Japanese people were able to just chop the tall branches off the top of the trees as if they were tree trunks, and the trees underneath them would continue to grow.

Advertisement

This means that a single tree could give large, thick, and quality lumber every ~20 years while the tree itself would survive for centuries and won’t need to be replanted.

What’s even better is that the lumber from daisugi trees was 140% more flexible and 200% stronger and denser than regular cedars thanks to all the pruning. If this sounds counter-intuitive, let us explain:

By pruning the other branches of the tree the foresters don’t just “clear” room for a large single branch – they also allow the tree’s internal nutrients that would otherwise be enough for dozens of branches to all be used on a single “super branch”. Essentially, they’d trick the tree to “overfeed” a single branch, making it grow much thicker, stronger, taller, and straighter. 

Advertisement

An added benefit of all this is that the branch would be mostly devoid of any “knots” that are typical for wild trees, meaning that daisugi lumber requires less processing.

And, as Japanese culture has long favored wooden architecture over stone one because of the volatile climate in the region, daisugi lumber became a staple in Japanese architecture. From standard wooden roofs to the wooden beams in the famous tea rooms in Kyoto, daisugi cedar lumber was a highly valuable commodity in Japan for centuries.

Is daisugi still as widely used?

The demand for lumber dropped off in Japan in the 16th century but daisugi trees were already popular enough for arborists to keep pruning Japanese cedars in this manner. Ornamental outdoor gardens with daisugi trees also remained very popular for centuries and are why we can see daisugi trees even today.

Advertisement

In the wild, former daisugi cedars that have been allowed to grow unpruned have also created some very fascinating forests. The forests that cover Kyoto’s northern hillscape, for example, are especially gorgeous.

Kitayama Cedars 北山杉 Forest Industry of Kyoto(英語字幕付き)with English Subtitle

Is daisugi a viable forestry technique for lumber today or does it have a strictly ornamental purpose?

Today, in Japan and elsewhere around the world, daisugi is only used for ornamental gardens. However, it is a viable question as to whether it can be used for lumber today and more and more people are making that argument.

While worldwide we have plenty of flat lands that are suitable for forestry, we also have disastrous deforestation problems. And since maintaining wide and healthy forest areas around the world is crucial for maintaining a healthy climate, daisugi might be the answer climate experts have been looking for.

Advertisement

The problem, however, is obvious – the lumber industry is highly conservative and doesn’t accept change very well. And switching from the current model of cutting everything down and replanting forests only occasionally when the government makes them to daisugi will be difficult for the lumber industry. 

Here are the basic pros and cons of adopting daisugi as a mass forestry technique.

Pros:

  • Very high-quality lumber that’s much denser and more flexible than ordinary lumber.
  • Straighter and clearer lumber that requires less processing.
  • Sustainable forests that don’t need to be cut down and replanted.
  • Incalculably enormous environmental benefits as forests worldwide will be in a much healthier state.
  • Fantastically beautiful forests.
  • As implementing the daisugi arborist technique worldwide would require extra man hours (we’ll mention that as a con below too), this may open lots of additional well-paying jobs in a time of increasing low-pay jobs and poverty.

Cons:

  • The daisugi technique requires time and effort. Expertly pruning each tree so that it grows the right way will take manhours the lumber industry prefers not to invest in. This will include both a lot of know-how training as well as a lot of investments.
  • The previous point will likely also mean an increased cost of lumber-derivative products such as furniture, paper, etc.
  • Not all trees are as suitable for daisugi as the Japanese cedars. So, some types of lumber will either become rarer or the deforestation effect of the lumber industry will continue.
  • The decisive con, however, is that this would simply be something new, unfamiliar, and unorthodox for western lumber companies in particular and that alone would be a deal-breaker for most of them. Unfortunately, most industries across the world are not yet ready to comply with the environmental needs of our planet and the lumber industry is no exception.
Advertisement