How to Build an Air Pruning Box

If you want to propagate a lot of trees, we highly recommend building an air pruning box. We have found this to be the best grow method for producing healthy saplings with ideal root structure. It is also cheap and easy to build.
This also allows you to grow hundreds of trees in a small space. We have grown 500+ seedlings in 2ft x 4ft box.
An air pruning box is one that has an open bottom with a wire mesh holding the soil and saplings in place. As the roots push downward and poke out of the holes in the bottom, they encounter air. Once this happens, they stop growing vertically and begin creating side lateral roots. The net result is a tree with a well-formed root system that can develop into something strong and healthy after being planted in the ground.
There are many, many ways to make air pruning boxes. If you search online, you will find countless designs in a range of options and complexities. So long as they have an open bottom, most any system will probably work just fine.
Here are the tools and supplies you will need for the boxes we like to build:
o 2” x 8” treated lumber (or wood of your choice)
o 2” x 6” treated lumber
o 2” x 2” treated lumber
o 3” angle brackets
o 3” T brackets
o 1-1/4” deck screws (screws are far more effective than nails for this application)
o Hardware cloth (½” x ½”)
o Hammer
o Fence staples or industrial staple gun with matching staples
o Power drill with screwdriver bits (or screwdriver if this is not an option)
o Leaf mold or leaf compost
o 8 bricks or 4 cinder blocks
o Miter saw, circular saw, or manual saw for cutting lumber
o Offset snips for cutting wire

[@farmyourbackyard2023]

Thanks for the tutorial!

[@jesseandbriannamartin6562]

Amazing, thanks!

[@Norbingel]

Won't the mesh rust quickly? Maybe plastic mesh instead?

[@jeffmartin924]

Treated lumber might not be the best

[@Leaflimb]

We have not had an issue with it - the trees have consistently been happy/healthy