Air prune beds

Taprooted trees are hard to propagate in a nursery setting. As soon as you dig them out, you disturb the tap root, which might stop it from growing, or worse, you might break the tap root altogether.

The ideal way to propagate taprooted trees is therefore to plant them where you want them and never move them again. However, it is not always possible or practical. For instance, nut trees are an easy prey to squirrels and chipmunks if not protected. When trying to propagate thousands of them, it is much easier to plant them in a nursery bed and protect them, which means you need to transplant them and run into the whole taproot issue.

Akiva Silver from Twisted Tree nursery made a short video showing his air pruning beds for growing taprooted trees. The idea is that the mesh at the bottom exposes the roots to air which stops it from growing.

I love Akiva's selection (I've ordered seeds; no trees yet), articles, and videos. I'm looking forward to his book.

I haven't been able to find much detail on how to build an air prune bed like this. I'd pay Akiva good money for an ebook.

Air pruning this way sounds great. I have to give it a try on my scale.

My much better half and I start every avocado pit we get. This started as an art exhibition involving large glass orbs showcasing root zone development.

We now have over a dozen potted plants, with the oldest, at four years old, taller than me.

Would it work, though, to start the pits in tall tubes or open-bottomed pots sitting on mesh over a drip tray?

-CK

I'm on board with the theory. I see that keeping trees too long in pots makes them weird.
This explains it pretty well.

webpage

But who really knows if afterwards these trees with an unnatural amount of side branched small roots will indeed develop a strong rootsystem with a thick strong penroot and strong thick rock crushing side branching roots? I believe these air pruned trees get the immediate start most replanted trees don't have. It makes sense, they will quickly capitalize on the surrounding nutrients with their well developed small roots system. That is not a guarantee that long term growth will occure though.

The old system might not be perfect, and it might take a long time for trees to really get started, but i seriously doubt this is a tried and tested method. In the long run your air pruned trees might all blow over by the wind. Is it really great to have a lot of first year growth in leave volume and branches above the ground if the ankering is not keeping up?

I'd like to be proven wrong, but my liking of Akiva Silver, i loved,loved ,loved his book is not going to keep me from expressing my doubts.

I grow with soil blocks that airprune veg. seedlings and they work really well. Air pruning in nurseries here in Maine seem to work well too. Here's an article from MOFGA:

https://www.mofga.org/resources/maine-heritage-orchard/sharing-rare-plant-material-at-the-seed-swap-scion-exchange/

And they look really easy to build. There's an explanation in the MOFGA article and also here:
https://www.motherearthnews.com/organic-gardening/growing-bare-root-trees-with-air-prune-beds-zbcz1903/

Adrien Lapointe wrote:

Akiva Silver from Twisted Tree nursery made a short video showing his air pruning beds for growing taprooted trees. The idea is that the mesh at the bottom exposes the roots to air which stops it from growing.

I love this as it could solve a lot of tree planting issues for me. However….
Does the tap root from air-pruned-started trees have the same length and breadth of taproot than saplings started in ground, in place? Has anyone compared the roots from the two scenarios?

I ask because it would not be good to have, for example Oak trees, without an adequate taproot. They won’t be as resilient re attaining water and nutrients and they won’t be as stable in high winds and heavy wet soils.

Sean at Edible Acres has a playlist of twelve videos on Air Prune boxes that he's been posting about for years. (I think he first credited Akiva Silver too, IIRC.) This is the start of that:



Anway, I agree with those above who say it would be good to know how it compares with tap root health of a tree planted at its final destination, because it's always good to know, but if it's a midpoint between planting in a pot and letting the tree get weird, and planting the seed in its final destination, it still might have a valuable place for those of us growing seeds.

I built four 1x2 foot beds but I need a wire box on top because the squirrels or chipmunks extracted my *entire* chestnut crop last spring.

I have not compared the taproots. It would be interesting to do so.

I did try to start trees from seeds in their final location and it can be a challenge due to competition with grass or other plants. Nursery beds make it easier to control the competition. Anecdotally, it seems to not be too detrimental. I have friends who have started and planted trees from air pruning beds without apparent problems (so far).

According to Robert Kourik in his book Roots Demystified, air pruning is the next best thing to seeding in place (for which there is no substitute). The research comes from the logging industry seeking the most effective and efficient way to replant deforested areas. The best method, according to Kourik (and based on methods established in the 1980s) is a tube with ribbed edges to direct roots down and prevent root circling, including some holes at the base for air pruning. The best tube will also allow for easy removal of the tree seedling. Kourik's book is from 2008, and he complains that finding tube-grown seedlings is difficult. The next best approach, he suggests, is small seedlings in pots--the smaller, the better. Other sources have suggested that anything over 1 year old grown in a pot will be root bound. Moreover, staking is generally a bad idea; better to use nurse shrubs as windbreaks. The wind helps trees root in a healthy manner. If staking is required, best to use one stake on the windy side, screw in an eye screw to the sapling with one string tied to the stake.