Ebihara Board Technique and Drainage

[Bezalel Nebari]

When placing a tree on a wooden board in order to train the roots "Ebihara style", has anyone had issues with water not draining well because the board has no holes in it? The water has to drain off the sides and I wonder if that has caused any issues for anyone

 

[Dav4]

When placing a tree on a wooden board in order to train the roots "Ebihara style", has anyone had issues with water not draining well because the board has no holes in it? The water has to drain off the sides and I wonder if that has caused any issues for anyone

Nope, no issues using a board without holes. Make sure you do use good soil and your pot has good drainage... wooden boxes and anderson flats work great with this technique.

 

[Ohmy222]

I haven't had any issue on the few I have tried either. That include tiles in the ground. I do recall someone in a podcast bringing it up though. Might have been Peter Warren. Either way I imagine the board normally not level so would have a natural slope to drain.

 

[Maiden69]

There are a few materials you could use. I use either tile or terracotta dishes. Wood is great if you are going to take the time and do and actually pin the roots as they grow out a wooden board will be better. Just don't use plywood, as it rots and the glue binding it breaks down leaving you with a mess.

 

[Canada Bonsai]

When placing a tree on a wooden board in order to train the roots "Ebihara style", has anyone had issues with water not draining well because the board has no holes in it? The water has to drain off the sides and I wonder if that has caused any issues for anyone

Bjorn spent an hour on the Ebihara technique in BonsaiU. I was surprised to see that he screwed the tree directly to the bottom of the box, and not to a separate board that was then placed into the box. I bring this up here because you can see in the images that there are only 4 drainage holes at each of the corners, and so the implication is that using a board without drainage holes should not be an issue.

On a separate note: through a good friend in Japan, I recently put forth the question to one of Ebihara's students as to whether having substrate beneath the board is important or unnecessary in their experience. I should hear back soon.

I personally have always used a board (or tile) without drainage holes.

 

[Maiden69]

If I had the space I would do the same way instead of using a tile... I place soil under the tile and I have round 1" space between the tile and the bag for the roots to grow down. This will help the roots close to the tree to fuse and thicken, but will not give me that wide pancake look that the E. method produces. Right now I am looking for a wider root spread that will "hopefully" give me a wider basal flare. I screw my trees to the tile from the bottom as well.

 

[Bezalel Nebari]

Bjorn spent an hour on the Ebihara technique in BonsaiU. I was surprised to see that he screwed the tree directly to the bottom of the box, and not to a separate board that was then placed into the box. I bring this up here because you can see in the images that there are only 4 drainage holes at each of the corners, and so the implication is that using a board without drainage holes should not be an issue.

On a separate note: through a good friend in Japan, I recently put forth the question to one of Ebihara's students as to whether having substrate beneath the board is important or unnecessary in their experience. I should hear back soon.

I personally have always used a board (or tile) without drainage holes.

Definitely interested in hearing their response. Thank you

 

[Dav4]

I vote yes for soil underneath the board… The roots will quickly grow to the edge of the board and you want them to keep on growing. Having that soil underneath allows the roots a place to run which will give better results sooner.

 

[Bezalel Nebari]

I saw someone recommend using pine. Is that what you use?

There are a few materials you could use. I use either tile or terracotta dishes. Wood is great if you are going to take the time and do and actually pin the roots as they grow out a wooden board will be better. Just don't use plywood, as it rots and the glue binding it breaks down leaving you with a mess.

 

[Maiden69]

I saw someone recommend using pine. Is that what you use?

I don't use wood currently, but if I was I would consider cedar, white or red oak, redwood, ipe... pine is not a good material if it is going to be subject to the elements. Pressure treated pine is ok, but "could" be toxic to your trees. They are treated with different types of chemicals and pesticides so there is no knowing what they have in. Definitely no plywood. Cedar is plentiful in hardware stores, you can get fence pickets as wide as 12" that you can cut to size.

 

[meushi]

Just don't use plywood, as it rots and the glue binding it breaks down leaving you with a mess.

Surprisingly, the thin plywood (1/4") I have used for some Japanese maple whips hasn't yet broken down at the end of the second year. There isn't enough substrate above it to retain much humidity. It is getting slightly wobbly, but hasn't delaminated yet. The one page drawn explanation that is usually posted in the Ebihara thread (the Kyosuke Gun one) specifically says to use plywood (veneer board in Japanese) as the base, only have one layer of substrate on top of it and to repot every year.

 

[Maiden69]

Surprisingly, the thin plywood (1/4") I have used for some Japanese maple whips hasn't yet broken down at the end of the second year. There isn't enough substrate above it to retain much humidity. It is getting slightly wobbly, but hasn't delaminated yet. The one page drawn explanation that is usually posted in the Ebihara thread (the Kyosuke Gun one) specifically says to use plywood (veneer board in Japanese) as the base, only have one layer of substrate on top of it and to repot every year.

In all honesty it all depends on where in the world you are. I used to do wood working as a hobby, anything from cabinets, speaker boxes, some tables, and guitars. If I leave a piece of regular plywood outside (anything smaller than 1/2") and it got wet, it will coup. Let alone keeping it under soil watering it daily with a bunch of nails stuck in it.

 

[Pitoon]

Bjorn spent an hour on the Ebihara technique in BonsaiU. I was surprised to see that he screwed the tree directly to the bottom of the box, and not to a separate board that was then placed into the box. I bring this up here because you can see in the images that there are only 4 drainage holes at each of the corners, and so the implication is that using a board without drainage holes should not be an issue.

On a separate note: through a good friend in Japan, I recently put forth the question to one of Ebihara's students as to whether having substrate beneath the board is important or unnecessary in their experience. I should hear back soon.

I personally have always used a board (or tile) without drainage holes.

I have screwed trees from below onto a board and then placed into a pot with no holes on the board. I'm curious to hear what the student replies back with regarding the substrate.

 

[Pitoon]

In all honesty it all depends on where in the world you are. I used to do wood working as a hobby, anything from cabinets, speaker boxes, some tables, and guitars. If I leave a piece of regular plywood outside (anything smaller than 1/2") and it got wet, it will coup. Let alone keeping it under soil watering it daily with a bunch of nails stuck in it.

I use PT wood rated for ground contact. Marine grade plywood would last, but I don't think the cost would be worth it.

 

[Maiden69]

I lived near a facility that treated PT pine... I use it for construction, but I don't think I would want it right under my tree. Then again, that was in the 1980-1998, so a lot has changed since then.

 

[Pitoon]

I lived near a facility that treated PT pine... I use it for construction, but I don't think I would want it right under my tree. Then again, that was in the 1980-1998, so a lot has changed since then.

The chemicals used then and now are different for PT wood. At that time the main chemicals used was arsenic and chromium. Those has since been banned and now producers use alkaline copper, copper azole, or micronized copper azole. There's no issue using PT wood for this purpose, however if you have a fruit tree and plan to eat the fruits......DO NOT use PT wood.

 

[Ohmy222]

I have used marine grade plywood for most of mine (4x4 at home depot). I then put a couple coats of stain on it. I haven't had any issue with the trees or the wood rotting. I have used sheets of pvc sheeting too for smaller trees. Not sure if it is really called pvc sheeting but they are similar to foam board but some sort of plastic. Probably 1/8 inch thick and the one I got was 4x8 and probably $30 or so. you can use a razor and cut it as needed. They don't seem to rot from what I can tell. I just thread some wire through it since they aren't big enough to screw down. Also use on some air layers to get radial rooting.

 

[Pitoon]

I have used marine grade plywood for most of mine (4x4 at home depot). I then put a couple coats of stain on it. I haven't had any issue with the trees or the wood rotting. I have used sheets of pvc sheeting too for smaller trees. Not sure if it is really called pvc sheeting but they are similar to foam board but some sort of plastic. Probably 1/8 inch thick and the one I got was 4x8 and probably $30 or so. you can use a razor and cut it as needed. They don't seem to rot from what I can tell. I just thread some wire through it since they aren't big enough to screw down. Also use on some air layers to get radial rooting.

Are you referring to the expanded PVC sheets? Those should work good and the sheet is not expensive at all and very easy to cut.

 

[MrWunderful]

100% not needed, especially for trees in the ground.

 

[meushi]

In all honesty it all depends on where in the world you are. I used to do wood working as a hobby, anything from cabinets, speaker boxes, some tables, and guitars. If I leave a piece of regular plywood outside (anything smaller than 1/2") and it got wet, it will coup. Let alone keeping it under soil watering it daily with a bunch of nails stuck in it.

We do share more than one hobby then
The North-East of France isn't exactly known to be dry... it tends to be agreeably moist throughout the year. Same thing with Japan... it's normally very humid. My garden is unusually extra moist as there's a major river running at the back, I am surrounded by my own private wood and it turns into an island for a few months every year. We do have roughly the same average rainfall in the year, but I'm getting that in about 8 months of wet weather. You get an average of 71 days of precipitations, I get an average 180 days of rain and 24 days of snow
This is a 1/4" plywood root board that spent Spring 2020 in a pot, then was left exposed to the elements since. As you can see, it is starting to delaminate on the edges but is still surprisingly intact in its second season growing seasons outside. The delamination has only started this month. It's not even a fancy plywood, it's the cheapest interior grade plywood sheet I could find at a discount big box store. It would probably last a whole lot longer if I used some spar varnish on the edges.