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.
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?
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein
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.
Creating edible biodiversity and embracing everlasting abundance.
Stinging nettles are edible. But I really want to see you try to eat this tiny ad: