Air Prune Bed with Pics

I built this air prune bed to propagate grapes, hazelnuts, rose and various other things. Got the idea from Twisted Tree Nursery and Edible Acres. I used the natural wood slabs left off from a bunch of logs we had milled up. I think it turned out great! Has anyone else had experience using these beds?
From my understanding, the plants to be propagated are planted in and as the root grows, it hits the hardware cloth and the circulating air and then stops. Then the root ball develops OUT instead of DOWN to create a very robust root ball come transplant time.


(Edited to add - Sorry for the lame pictures loading sideways! I'll try to fix this...)

Neat idea! Are you going to do cuttings in it, or seeds? Most of my cuttings tend to grow out instead of down naturally, but I can definitely see how it would stop a taproot from a seed.

Do you know if the tap root continues to develop properly once the plant is in the ground?

Mike, I’ve seen this mostly for things with a shallow fibrous root like ribes , but I think the taproot belief is overstated in most soil types and mostly important in young trees. I can attest that after uprooting a few thousand trees grown from seed on my place (which is not a drought prone area) zero had identified taproots with the exception of a persimmon. Some persimmons didn’t.

In the west in sandy soils- sometimes. But all trees can make sinker roots anyway. For tree establishment in dry climates they are helpful.

I use treepots in a wood chip bed, the roots hit the chips as they get to the edge of the pot and they get a similar effect. Sometimes there’s a taproot that makes it down but they transplant fine even if I cut the taproot.

Some reading on taproots: https://robertkourik.com/taproot-tidbit.html

That's good to hear Tj Jefferson. It makes sense that they can make a taproot later. But how to be sure?
I like these airpruning beds, i'd like to make some too. Wish i had some acacia pseudorobinia planks to bang out some smaller beds. I would like to move them to the shade to restrict watering in summer. They are good to pump out loads of trees and easier to protect. When the roots hit the bottom they develop sideways and really fill out the space.
The man from twisted tree nursery Akiva Silver wrote a very good book:" Trees of power".

First, a little background.  I live in the desert.  I have about 40 fruit/nut trees, almost as many vines, and a tropical greenhouse. I do a limited amount of seasonal gardening.  I have a grow room with lights.  Everything outside is under 90% shade cloth.  Even at that, nothing was growing like it was growing in, lets say, the Pacific Northwest.  Everything was stressed to a little or more degree.  So what I did was take everything I could out of the ground, chopped the main leader branch down to either 18 or 24 inches, and put them in self made air pruning pots.  My water bill has halved, everything is gloriously beautiful and they are bearing more fruit/nuts.

When I first started with this new project I bought air pruning pots from both makers, Root Makers and Air Pots.  They are nice and they are not nice.  I didn't like that they were black...its a vibration thing with me.  Plus, if one wants to have them in an area where temps are high, it is going to heat the roots unnecessarily. I also noticed that they dried out quickly (media was coir/perlite/vermiculite). And sometimes the media leaked out the holes.  For that price, wasn't working for me.  So I went to Walmart and got 5 gallon BPA free buckets for $3.00.  I put rows of holes in them and fastened pink shade cloth around the circumference, fastened with zip ties.  I then put them in rectangle storage containers (the black ones with the yellow lids, minus the lid of course)  I drilled a hole in the bottom side of the black container and put a cork in it.  In the winter rains, I can take the cork out and all that water doesn't drown my trees, plus the bin keeps the air pruned pot a little warmer.

So anyway, after researching air pruning pots at the Root Maker site, I began to understand that this method is an ongoing transplanting situation.  You start with a very small seedling size air prune pot so that the roots will cramp.  Then when they completely fill up the container you move up to the next size.  At some point, depending on the size you want to be growing, you might have to move them to the ground (like if you want a 15' fruit tree).  But I am keeping mine espaliered or super dwarf.  More trees but smaller trees equates to less work, less water, etc for me. Especially because I live on a mesa with regular 40mph winds.

So it has to be understood, the whys and wherefores of this method.  You can't plant something small in a large air prune pot/plot.  It won't develop feeder roots correctly.  IF a plant or tree has a thousand feeder roots, it does not really even need the tap root. That is what is behind the air pruning method.  You could do the same thing with plastic drinking cups, move them up, move them up, until you have what you want.

Purity Lopez wrote: You can't plant something small in a large air prune pot/plot.  It won't develop feeder roots correctly.  IF a plant or tree has a thousand feeder roots, it does not really even need the tap root. That is what is behind the air pruning method.  You could do the same thing with plastic drinking cups, move them up, move them up, until you have what you want.

Very true. In my bonsai projects, I keep various sizes of colanders on hand for developing root systems. I like colanders (or pond filter baskets) because they are more wide than they are deep, which allows the tree to develop a wide span of horizontal feeder roots instead of a deeper system of anchoring roots (which isn't needed/desired in bonsai).
Although it's more of an ornamental hobby, bonsai has helped me learn how trees grow, and are influenced by different variables in growing conditions. From there it's easier to apply those principles on a larger scale with food-producing trees.

Background: I'm working on growing a lot of trees and shrubs to repopulate about half of my 8 acres of former forest that was selectively logged before I got there, and now is full of diseased and dying oak, maple and beech. I also hope to start a nursery operations in the coming years, so I'm working on building systems of growing trees and establishing mother plants to collect propagation material from in the future.

I got the idea for air pruning beds/boxes from the same source as the OP. I built some smaller boxes like Sean at Edible Acres, but have also been experimenting with larger beds. The twist I put on it is building them with cinder blocks instead of wood. The larger beds don't need to be mobile, but using cinder blocks makes them very modular. You can also entice lateral root pruning by using cinder blocks, where you can't using wood. If you turn the blocks sideways, where the openings face the inside of the bed instead of up and down, you can then put hardware cloth around the perimeter of the bed, and voila, same effect on the sides as on the bottom.

Over the next few weeks I plan on making several smaller versions of this, maybe 16"x48" or similar (based on standard cinder block dimensions), and high enough from the ground so I don't have to bend to work in them (back problems), so I can have one bed for each species of seed. Cinder blocks are cheaper than lumber currently, and can last indefinitely without concerns about chemicals or finding the right species of tree wood. On top of that, they require no nails or other assembly, just stack them and sandwich the hardware cloth between the top layer of cinder blocks and the next one down!

I'll try to post a few pictures of the larger bed I have built as well as the smaller ones I mentioned building above.