Sizing a Grow Box

[The Warm Canuck]

This is based on the stage of development of the root ball once again. I do the most that I can in one session. But this will be different depending on what I find with each particular tree. The destination is usually a couple of stops away.

Leaving the root ball just large enough to allow roots room for some growth is important when collecting yamadori and during the first stage of recovery. ( key thought: often the advice we receive is based on a particular set of circumstances not for general use each time we approach a tree) This may and often should involve a change of sizing in grow boxes or maintenance pots as the tree progresses in developing finer feeder roots.

The tree has a nursery pot developed root ball and was transplanted without root work or disturbing the mass a short time ago. Actually in reality, probably has never had root pruning for development.
As a maple I would carefully bare root, wash out nursery soil. Reduce the strongest roots, particularly the downward ones. Locate the best root spread for nebari. If the root ball was really healthy in appearance I would likely reduce by 2/3 the first go. If I found a less than healthy situation, I would remove all dead roots and keep all healthy roots.
In other words adjust the situation depending on what you find.

I would advise focussing on #1 and #4 first.
When the tree has shown strong signs of recovery after potting. Than begin pruning/ cut back to accomplish the other goals.
If you stage the work the recovery will be faster with better root growth due to the extra foliage and reserves left in the tree. This in turn will give you a stronger tree for better response when cut back.

Got it,

I'm just going to make a few different sizes of grow boxes. I'll make a 12x12x6, and a 14x14x6, this should allow in a variation of size based on the healthy root size.

I'll have to read up on Nebari root spread.

If it appears healthy, would doing the cut back in the summer work? Or give it another season?

 

[River's Edge]

Got it,

I'm just going to make a few different sizes of grow boxes. I'll make a 12x12x6, and a 14x14x6, this should allow in a variation of size based on the healthy root size.

I'll have to read up on Nebari root spread.

If it appears healthy, would doing the cut back in the summer work? Or give it another season?

Depends on the apparent recovery and what you find when you do the root work? Bonsai is a marathon not a sprint. Pace yourself and your trees. Actually there is no destination, just the journey. Enjoy the journey!

 

[parhamr]

You’ve got an interesting specimen and I’m excited to see what comes of it. I’ll drop a huge +1 to everything @River's Edge has said. I want you to feel confident and inspired so please consider this to whet your appetite…

Regarding root work, here’s what a sustainable reduction and cleaning can look like. This 6-7 gallon pot was filled with roots from this Shishigashira. I dug down from the top, located the flare, and then lopped off the bottom half with a sawzall



These maples store plenty of energy in the tissue to come back from root work. All told, that reduction still had a huge bit of margin remaining. Your species is stronger than my example.

Next, regarding box sizing, what if you tried 16"? I’ve found it to be very viable and sustainable for trees in the size class of your example. It doesn’t take long for a strong maple to fill the box with roots. Here, my boxes are 16" square for outer dimensions and 3.75" deep. It works great. These photos are in chronological order. Note how enthusiastically the tree canopy will grow once you’ve got the roots sorted.



(Standard Japanese Maple; the soil is about 50 percent clean pumice, 25 percent akadama, and 25 percent reused soil)

Finally, regarding a heavy prune (Frank is right about delaying that until after the root work), here’s how well a tree can respond in one season. Trees of this size range and with healthy roots are less likely to have massive die back. It’s a five month separation between these the chop and the next .



(Trident maple)

You’ve got this! In closing — patience and timing are your path forward. Don’t push on it too much in any given season. You’ll get where you want to go more quickly through bulking and then chopping rather by heavy restricting and controlling.

 

[The Warm Canuck]

You’ve got an interesting specimen and I’m excited to see what comes of it. I’ll drop a huge +1 to everything @River's Edge has said. I want you to feel confident and inspired so please consider this to whet your appetite…

Regarding root work, here’s what a sustainable reduction and cleaning can look like. This 6-7 gallon pot was filled with roots from this Shishigashira. I dug down from the top, located the flare, and then lopped off the bottom half with a sawzall
View attachment 412587
View attachment 412588

These maples store plenty of energy in the tissue to come back from root work. All told, that reduction still had a huge bit of margin remaining. Your species is stronger than my example.

Next, regarding box sizing, what if you tried 16"? I’ve found it to be very viable and sustainable for trees in the size class of your example. It doesn’t take long for a strong maple to fill the box with roots. Here, my boxes are 16" square for outer dimensions and 3.75" deep. It works great. These photos are in chronological order. Note how enthusiastically the tree canopy will grow once you’ve got the roots sorted.
View attachment 412589
View attachment 412585
View attachment 412586
(Standard Japanese Maple; the soil is about 50 percent clean pumice, 25 percent akadama, and 25 percent reused soil)

Finally, regarding a heavy prune (Frank is right about delaying that until after the root work), here’s how well a tree can respond in one season. Trees of this size range and with healthy roots are less likely to have massive die back. It’s a five month separation between these the chop and the next .
View attachment 412582
View attachment 412583
View attachment 412584
(Trident maple)

You’ve got this! In closing — patience and timing are your path forward. Don’t push on it too much in any given season. You’ll get where you want to go more quickly through bulking and then chopping rather by heavy restricting and controlling.

Thank you so much, if you goal was to inspire me, well it sure did work!

Sure, I'll make a 16*16*5 also. I like the idea of making the boxes a little deeper and just not filling them all the way up, if not required. My mix is primarily lava rock, pine bark and a little left over turface.

No kidding, when you say you get aggressive growth when focusing on the roots first! Thats some impressive growth.

Two questions: 1. I see you made your grow boxes, using 45deg miters, like a picture frame. Do you find that this makes the boards cup less? I have a few I've made, just using butt joints, and they cup pretty severely.
2. Why just a nursery pot for the trident, and no grow box?

 

[parhamr]

Thank you so much, if you goal was to inspire me, well it sure did work!

Sure, I'll make a 16*16*5 also. I like the idea of making the boxes a little deeper and just not filling them all the way up, if not required. My mix is primarily lava rock, pine bark and a little left over turface.

No kidding, when you say you get aggressive growth when focusing on the roots first! Thats some impressive growth.

Two questions: 1. I see you made your grow boxes, using 45deg miters, like a picture frame. Do you find that this makes the boards cup less? I have a few I've made, just using butt joints, and they cup pretty severely.
2. Why just a nursery pot for the trident, and no grow box?

The trident has been in that nursery can for about 8 years. It was a bargain I got at a nursery close out in April. Since it was in leaf I didn’t want to mess with the roots, so it’s an example of using established, powerful roots to supercharge the next growth spurt.

Yes, the 45° miters really seem to help the entire thing stay together and strong. This is especially true for the 7/8" thick wood I was using. I have still had minor cupping but the opposing forces are all holding together well. The bottoms of my boxes have 3 or 4 slats to additionally help with rigidity. I used butt joints on 5/4" and thicker wood. (It’s all Western Redcedar)

I have made some 5 or 6 inch deep boxes and only in very rate situations have I actually needed that depth. Most have been too large.

Here are some box closeups. Feel free to steal or borrow any ideas

 

[The Warm Canuck]

The trident has been in that nursery can for about 8 years. It was a bargain I got at a nursery close out in April. Since it was in leaf I didn’t want to mess with the roots, so it’s an example of using established, powerful roots to supercharge the next growth spurt.

Yes, the 45° miters really seem to help the entire thing stay together and strong. This is especially true for the 7/8" thick wood I was using. I have still had minor cupping but the opposing forces are all holding together well. The bottoms of my boxes have 3 or 4 slats to additionally help with rigidity. I used butt joints on 5/4" and thicker wood. (It’s all Western Redcedar)

I have made some 5 or 6 inch deep boxes and only in very rate situations have I actually needed that depth. Most have been too large.

Here are some box closeups. Feel free to steal or borrow any ideas

Ya, I use slats also. My boxes look pretty well identical to your except the 45s. I just bought some 1/4" chicken wire that I'm going to use over the pet screen I use, to give me less sagging, enabling more distance between slats. I just use pressure treated, cedars too pricey here. I would like to try making some boxes with the PVC their using for decks now.

On another note, I have an Burr Oak that I also planted in the fall. My plan was to air layer it, but after reading how difficult it is to layer an oak, I'm not going to try. Now this tree is about 12' tall. 3" trunk. Its a landscaping tree, so there's no branches at the bottom of the tree. I'd also like to get it out of the ground. How would one deal with such a tall tree? Would it be better to trunk chop it, late winter than dig it up the following season? The root ball was in a 35gallon pot, and it was pretty root bound.

 

[parhamr]

Ya, I use slats also. My boxes look pretty well identical to your except the 45s. I just bought some 1/4" chicken wire that I'm going to use over the pet screen I use, to give me less sagging, enabling more distance between slats. I just use pressure treated, cedars too pricey here. I would like to try making some boxes with the PVC their using for decks now.

On another note, I have an Burr Oak that I also planted in the fall. My plan was to air layer it, but after reading how difficult it is to layer an oak, I'm not going to try. Now this tree is about 12' tall. 3" trunk. Its a landscaping tree, so there's no branches at the bottom of the tree. I'd also like to get it out of the ground. How would one deal with such a tall tree? Would it be better to trunk chop it, late winter than dig it up the following season? The root ball was in a 35gallon pot, and it was pretty root bound.

Hardwood species like oak have a fun trick — “sweating” in a black trash bag. There are people who successfully trunk chop and/or collect oaks (and other tricky species) from the wild by putting them inside a bag to keep them warm and humid. Apparently the buds just burst out from the old bark.

I don’t know anything about the details, though. Good luck on the research

It sounds like you’d have more luck to use its current, in-ground roots to power the rebuild of a lower canopy. There’s still a huge bit of risk and a gamble in that, as you might not be successful when eventually digging it up and pot it. Fortune favors the bold?

 

[leatherback]

I don’t know anything about the details, though. Good luck on the research

Improving the success rate of Yamadori

I have been using this technique now for over ten years and I have finally decided to share what I have learned. The technique is known as ‘sweating’ and is used extensively in arboretorial circles…

yamadori.co.uk

Black Bag – Bonsai & Yamadori from Tony Tickle

Posts about Black Bag written by Tony Tickle

yamadori.co.uk

 

[The Warm Canuck]

Improving the success rate of Yamadori

I have been using this technique now for over ten years and I have finally decided to share what I have learned. The technique is known as ‘sweating’ and is used extensively in arboretorial circles…

yamadori.co.uk

Black Bag – Bonsai & Yamadori from Tony Tickle

Posts about Black Bag written by Tony Tickle

yamadori.co.uk

Thanks for the info, I'm going to start another post asking about this. I've hijacked my own thread haha

 

[Mike Corazzi]

I'm gonna switch to ikebana.

 

[SC1989]

Screen boxes .. I was a bakery manager for years. I had some damaged donut frying screens. Probably 18 x 24 inches. I put an acer rubrum from a 5 gallon pot in it. Easily filled it with roots last summer