Grow Box Size

[coltranem]

Hi,
I am looking to get two of my trees into grow boxes next spring but I am a little unsure what size to make. I'd love some advice.

Tree 1: Red Maple
This has been growing out for size in a 2 gallon nursery pot. It sits abot 3 feet tall with a 1.25 root base. I'd to get it into a flat grow box to start building a flat root base. My thought on size is 5-6 inch deep and maybe 16 inch square. My target is a two foot tree with approximately 4 inches of base.

Tree 2: Small Juniper
I acquired this tree this summer and it is pretty root bound. I'd like to start getting it more vigorous and start a flatter base. This tree has a 1 inch base which I would like to grow. My size guess here is 3 inch deep 12 inch square.

 

[River's Edge]

Hi,
I am looking to get two of my trees into grow boxes next spring but I am a little unsure what size to make. I'd love some advice.

Tree 1: Red Maple
This has been growing out for size in a 2 gallon nursery pot. It sits abot 3 feet tall with a 1.25 root base. I'd to get it into a flat grow box to start building a flat root base. My thought on size is 5-6 inch deep and maybe 16 inch square. My target is a two foot tree with approximately 4 inches of base.

Tree 2: Small Juniper
I acquired this tree this summer and it is pretty root bound. I'd like to start getting it more vigorous and start a flatter base. This tree has a 1 inch base which I would like to grow. My size guess here is 3 inch deep 12 inch square.

View attachment 214282View attachment 214283

For the maple i would build something 3-4 inches deep and 18 inches square. For the juniper i would use a deeper boxes 5-6 inches deep and 13 to 14 inches square. keep in mind the depth will not be filled completely and the method of construction may also reduce the depth. Ensure that the construction raises the base off the ground and the drainage is sufficient. it also helps to provide handles for the boxes.
Use solid wood not ply wood, particularily if you have a wetter climate.

 

[coltranem]

I guess I should have been more clear. I meant the depth inside or usable depth not outside depth.

 

[coltranem]

@River's Edge just curious why shallower on the maple.

 

[River's Edge]

@River's Edge just curious why shallower on the maple.

Generally speaking you are trying to develop a shallower root base on maples, they are usually shown in shallower pots. The shallower box promotes that in keeping with more flare and radial spread that comes off the trunk. Spend some time looking at show maples and you will observe what i have mentioned.

 

[River's Edge]

I guess I should have been more clear. I meant the depth inside or usable depth not outside depth.

My dimensions refer to inside measurements.

 

[Gaitano]

These are the boxes I make, using 3.5" cedar. I can crank em out pretty quick. I think I cut the boards 10" long. Wood glue and a nail gun makes quick assembly.

 

[coltranem]

I have seen that Japanese and Trident Maples would use a shallower pot but from what I have read red maples need a deeper pot.

 

[Mike Hennigan]

These are the boxes I make, using 3.5" cedar. I can crank em out pretty quick. I think I cut the boards 10" long. Wood glue and a nail gun makes quick assembly.

Why 3.5 inch? Seems like an unecessarily HEAVY box. Cedar is already rot resistant, why not use a thinner plank? Something like a maple is not going to be in the box long enough for the cedar to rot. Maybe I am missing something. Please illuminate.

 

[River's Edge]

Why 3.5 inch? Seems like an unecessarily HEAVY box. Cedar is already rot resistant, why not use a thinner plank? Something like a maple is not going to be in the box long enough for the cedar to rot. Maybe I am missing something. Please illuminate.

The nominal dimension is likely referred to as 1 by 4 the actual measurements are closer to the 7.8 by 3 1/2 inch in various lengths. I use what is referred to as 1 by 6 actual dimensions are 7/8 thick by 5 3/4 inch wide in various lengths.

 

[River's Edge]

I have seen that Japanese and Trident Maples would use a shallower pot but from what I have read red maples need a deeper pot.

I have Japanese, Red and Trident in shallower grow boxes. I guess they never read the memo. I also use Anderson flats that are shallower and they still do well. With over 200 assorted Maples in development i do not feel like starting over.

 

[AZbonsai]

https://www.bonsainut.com/threads/heavy-duty-grow-box.30215/page-3

I just took my ficus out of this box I planted it in last year. Pretty happy with the results. Roots throughout the entire box.

 

[Mike Hennigan]

The nominal dimension is likely referred to as 1 by 4 the actual measurements are closer to the 7.8 by 3 1/2 inch in various lengths. I use what is referred to as 1 by 6 actual dimensions are 7/8 thick by 5 3/4 inch wide in various lengths.

Yes I am aware of how lumber measurements work, but 3.5, whatever the actual is, is still absurdly thick IMHO.

 

[Anthony]

Hehl heh ------ over-sized plastic bonsai pots

 

[jeanluc83]

Yes I am aware of how lumber measurements work, but 3.5, whatever the actual is, is still absurdly thick IMHO.

3.5 is the width not the thickness. The box shown looks like it is about 12" square. Filled with soil and a tree the weight shouldn't be more than 25#.

I've used 2x4s to build boxes before. They are cheap. The untreated ones last 4-5 seasons before falling apart.

 

[Wires_Guy_wires]

I used the "the box should be slightly bigger than the entire canopy" rule. It's a rule of my own writing, so it's correct.. At least for me.
And it worked pretty well.

For pines especially, use the cheapest non-treated wood you can find (fir or spruce or pine). Why? Because that wood is going to feed your mycorrhizae so much that you'll have a hard time finding soil components after 8 months.

 

[Anthony]

Nice idea @Wires_Guy_wires .
Will test sticking a chunk of pine wood in soil.
Thanks.
Good Day
Anthony

 

[Mike Hennigan]

3.5 is the width not the thickness. The box shown looks like it is about 12" square. Filled with soil and a tree the weight shouldn't be more than 25#.

I've used 2x4s to build boxes before. They are cheap. The untreated ones last 4-5 seasons before falling apart.

Hahahah ok that makes more sense, I guess I was confused ?

 

[River's Edge]

Yes I am aware of how lumber measurements work, but 3.5, whatever the actual is, is still absurdly thick IMHO.

The only aspect that is thick is the OP bottom blocks for feet. His initial statement of cutting 10" lengths should have given the information needed to figure that out. Actually the feet stay wet more than the rest of the box usually so that is a good choice.

 

[coltranem]

Great suggestions. I might make the smaller box first with 1 x something pine and see if I neec to go up for the bigger box.