“The Oregon Hole”

[parhamr]

This technique isn’t novel and I don’t know where it originated, but I’ve had a chuckle over the name “The Oregon Hole.” It’s stormy this week so I’ve been hiding under my carport and listening to podcasts and music while monitoring the drill. Here’s what I wrote up to explain the process to friends and it’s too fun to not share…

What is it? A small couple of holes through the bottom of a pot, located close to the outer wall.



What does it do? This hole allows bonsai enthusiasts to tip their pots upward to increase the height of the water column and to encourage better drainage in shallow pots.



Why is it done? Week after week of steady Pacific Northwest rains brings a risk of anaerobic conditions in bonsai pots, which invites decay and disease to roots.

How is it done? Turn a pot over and use a diamond-tipped or glass/tile/ceramic bit to drill into the pot. Do not apply pressure. To protect the pottery and drill bit from heat damage, either spray water or submerge the pot in a basin of water.



This technique is also important on slabs and natural stones. I use long masonry bits on the lava chunks I bring home.

Good luck!

 

[sorce]

Except where the pot shape deems absolutely necessary, I would jam a wire or four into the soil that can disrupt the "water table" and allow excess water to drop down it and out.

Tie wires are always serving this function.

Pandemic Drillers.

Happy Drilling!

Sorce

 

[Wires_Guy_wires]

But do keep in mind that both plants, microbes and fungi are "cold blooded" creatures; if the temperatures aren't high, there isn't much activity. And that cold water can hold way more oxygen.
I can keep meat anaerobic in the freezer for 4 years and still eat it raw. I can keep meat in the fridge anaerobic and still eat it after a couple days. I can keep anaerobic at room temperature and I can toss it out after three hours.

Wine for instance isn't just stored in dusty basements to keep the taste profile intact and preserve the cork.. It's also because a cold basement slows down biological processes.

Before everyone starts drilling their super expensive pots, this is something worth considering. The trees out there in the rain in pockets of soil usually get out of it unharmed as well.

 

[parhamr]

@Wires_Guy_wires in the temperate Pacific Northwest we get something like 75 percent of our annual rain when it’s around 5–13° C. Pathogenic activity is pretty common here!

Regarding the ceramics, I’ve only broken low quality, imported pots made from slip casting. High quality slab and wheel pots haven’t been an issue with cracking for me.

 

[Deep Sea Diver]

We do get a good deal of rain in the Pacific Nothwest, enough to do harm to our trees, so it is common practice out here to at least ‘chock‘ up one side of our pots to lower the water table in our pots.

Some of us do drill extra drain holes in their pots, especially in ones that were not well designed to start with. Ive been known to do it myself. @River's Edge has also got a nice technique for pot drilling I’ve used recently. Sounds gruesome but it works.

cheers
DSD sends

 

[Mikecheck123]

So uh...why didn't the pot have holes in it to begin with?

I don't see what this gets you over a normal pot with holes. You can tilt that just the same.

Also, you can do the same to any nursery pot to reduce the column of soil saturation.

 

[Deep Sea Diver]

Actually IMO it’s really about two things, water table and just plain overall everyday effective drainage. The rains just highlight the issue.

As an example why do a colander, Anderson pot or those perforated training pots work so well?

Also, if you look at enough pots, especially older ones, you’ll see some havent got large enough holes to start with. Just look at pots on FB 99 cent auction enough and you‘ll spot those you wouldn’t even think of putting a tree in in our conditions. I’m sure you noticed how the all the newer pots have much larger drain holes and additional smaller holes.

That’s my rationale, more drainage, coupled with good media yields good growth.

cheers
DSD sends

 

[parhamr]

So uh...why didn't the pot have holes in it to begin with?

I don't see what this gets you over a normal pot with holes. You can tilt that just the same.

Also, you can do the same to any nursery pot to reduce the column of soil saturation.

Certain styles of rectangles and ovals might not have the holes close to the walls (but in as much as 4 inches). Certain pots even have small internal bows or “lips” that prevent complete drainage. It totally depends on the potter.

Most of my pots are just fine. With some shallow pots I would have a constant, non-draining pool of water in the corner without an extra hole or two. We can have 60 straight days of cloudy drizzle, so by having the Oregon Hole I don’t have to bother moving the pot around a lot. Rather than an ad hoc, attentive schedule I can just let these pots sit up on one side for weeks without issue.

I have only watered once since about the end of October.

 

[parhamr]

Actually IMO it’s really about two things, water table and just plain overall everyday effective drainage. The rains just highlight the issue.

As an example why do a colander, Anderson pot or those perforated training pots work so well?

Also, if you look at enough pots, especially older ones, you’ll see some havent got large enough holes to start with. Just look at pots on FB 99 cent auction enough and you‘ll spot those you wouldn’t even think of putting a tree in in our conditions. I’m sure you noticed how the all the newer pots have much larger drain holes and additional smaller holes.

That’s my rationale, more drainage, coupled with good media yields good growth.

cheers
DSD sends

Yeah! I have some modern pots that are working great. By rough calculation the pots with the most drainage might be around 8% holes.

Certain older or poorer designed pots have as little as 2% bottom area in holes.

Notably, the hole positions can matter more for good drainage.

 

[River's Edge]

So uh...why didn't the pot have holes in it to begin with?

I don't see what this gets you over a normal pot with holes. You can tilt that just the same.

Also, you can do the same to any nursery pot to reduce the column of soil saturation.

Feel free to adapt any of the below ideas for wet climates or just enthusiast who water too much!
So, sometimes we use inexpensive pots designed for other uses and adapt them, sometimes we adapt them to suit our climate or fix design issues with the pots. Personally I do not drill expensive pots, after all show pots receive temporary use and it would be silly to risk damage to something of high value to improve drainage when it is only used temporarily for show purposes! Top show tree's do not live day to day in show pots.
1. terra cotta bulb pots can easily be adapted for Bonsai with better drainage, wire holes and slotted rim for gas exchange. At less than $5 each this is great for developing young or smaller Bonsai. Because terra cotta holds lots of moisture, improved drainage is desired for bonsai purposes. Four extra holes and slotted rim.




2. Inexpensive Bonsai pots with inadequate drainage can be improved. original holes too small, solution larger centre hole!





3. Better value pots can safely be drilled with the correct equipment and technique. Did you know Nan Ban style pots were originally storage container lids with holes drilled in them! Diamond bits, Rapid tap coolant and controlled drill stand. Allows controlled light pressure for chip free drilling in glass and ceramic. Pre drill tiny guide hole then begin the main hole from both sides before completing. Primary use for drilling bulkhead holes in aquariums for filtration and circulation equipment.




4. Sometimes tilting the pot can increase the amount of water retained in the bottom of the pot. One needs to check the positioning of holes and recessed areas in the inside bottom and edges.

*Can also be useful to drill side holes in plastic pots near the bottom rim for additional drainage and gas exchange.
* *Some were afflicted by this activity decades before the pandemic.
* **This is not a suitable substitute for effective balance of Bonsai soil components, suitable particle shape and size.
Happy Drilling!

 

[Wires_Guy_wires]

@Wires_Guy_wires in the temperate Pacific Northwest we get something like 75 percent of our annual rain when it’s around 5–13° C. Pathogenic activity is pretty common here!

Regarding the ceramics, I’ve only broken low quality, imported pots made from slip casting. High quality slab and wheel pots haven’t been an issue with cracking for me.

Ah, I didn't know. We get around 60% of our rain in winter. On average at least. Things have been shifting, last summer we had maybe one inch of rain in seven months. This week alone we had two inches of rain.
Now our rivers are at their highest level since 2010. Record after record. I might have to look into drilling holes ;-)

 

[pandacular]

This is a great idea. Now I’ve just gotta practice cleanly drilling holes in some of my cheap pots…