Planting rootbound trees: cut? cut & splay? leave bricked?

Is this a rootbound tree? It's a one year old graft of a Swiss stone pine onto a white pine stock. (I think...I should have checked since I've read white pines often reject stone pine grafts.)

Anyway the roots stop 1/2- to 2/3-way down the pot in each case, the oldest roots are set in a brick shape and the lower new ones, including the young tips, are also pot-formed but can be pried out and splayed.

The Arbor Day Foundation claims that in such cases the trees should be cut through their rootballs, with an X on the bottom and 4 vertical cuts made up the sides.

https://www.arborday.org/trees/planting/containerized.cfm

The illustration suggests that you are cutting the rootball up the oldest, topmost roots, but critically does not explain whether you should splay the roots in the hole, or leave the tree standing on its four weird new legs in the filled hole.

In this case I forced some roots out of the ball with my fingertips, but had to cut up towards the surface then splay the roots. Since I have 20 more trees like this to plant, I'd like to check that this violent technique is correct. After all, many tree-ignorant folks think pruning is bad by anthropomorphizing trees, but what seems counterintuitive to mammals is sometimes great for some other given organism.

I might cut if the roots are spiraled or snarled together, but if rootbound part is minor I just step on the ball to splay it out or step on it in the hole..

Growing in a pot creates a very unnatural root form, never assume it will be ok (unless it is a palm tree or similar). If a tree has root spiraling in the pot or otherwise non-natural formed roots the most likely scenario is it grows ok for 5 years, badly for another 5-10 years then falls over or dies. Bad outcome and to be avoided.

Yes it is possible to tease out all the roots and if you are extremely careful and have nothing else to do you can recreate a natural root system this way. But when I plant trees I am very hard on the roots, tough love is the only way to go. I remove the pot or planter bag and cut down 4 sides (to about 1/4 of the width of the rootball) with the planter spade making sure I sever every side root, very much like your arbor day suggestion. By doing this the tree is forced to grow new roots, which will then grow out into the soil in a natural way. If the roots in the base of the pot are tangled I have no issues with cutting off the bottom 1-2" or even more, depending on the size of the rootball. Then yes just plant it as if the rootball is still intact, splaying out the roots woul dbe a bad idea. Also I would not cut all the way through the rootball, only about 1/4 way form each side, unless the deformation is extremely bad.

Remember that not  doing this will eventually kill the tree, so what is there to loose?  I have planted many thousands of trees from pots with very few loses. My experience is relevant to my soils and climate of course.

Thanks Eric and Ben. I didn't think year-old trees would have developed potform yet; would you order from this nursery again? Plenty sell people rootbound trees with no compunctions. I fear I should replace these trees from someplace else, which will probably mean doing it next year. Buchholz & Buchholz were out of most stone pine varieties when I ordered these poor lil ones.

Those trees will do fine as long as you do as Ben mentioned.  Trees are very good at growing new roots when taken out of the pot and planted, the trick is to get the root ball cut up enough for there to be room for new growth in a more natural way.
Most people who have problems were too tentative about opening the root ball, they baby the roots from fear of harming the tree.
I use everything from snips to machete to open up root balls then, once I have them in the ground I make sure to water them in well and give them some B-12, which stimulates new root growth.
Keep the newly planted trees well watered and realize that they will do most of the root growth their first two years in their new home, then the tops will begin to flourish, showing they have made the transition.

Fredy Perlman wrote:I didn't think year-old trees would have developed potform yet; would you order from this nursery again? Plenty sell people rootbound trees with no compunctions.

I think there are two  issues here, firstly are you a 'natural' purist, and only want a perfect 'natural' rootball, or are you more interested in the long term result? If the former, you'll need to do some kind of direct-seeding approach, but remember that even in perfect conditions there might be some factor that creates root deformation in the root system.  Any nursery system is going to create an 'unnatural' root formation by the nature of the growing system, either following the shape of the pot, or root-pruning in an open field nursery.  You will find that even perfect air-pruning systems can still create deformed roots.

So what I'm saying is that realistically root deformation is going to occur in every nursery to some extent. Always assume it is bad, and have a good look at every tree before you plant it. It might take you a few seconds longer, but you will never regret it. Removing fully grown dead trees in 15 years is a pain in the neck.

Yes I would have no issues buying from the same nursery again. Even the nurseries employing the best growing systems can still create bad root systems at times, I would be checking the roots anyway, sometimes there are other factors that are more important, such as nursery distance and plant cost.

It must also be said that there are times when nursery people deliberately let the roots get bad.  When I am planting tender trees in inaccessible areas that require carrying through steep slopes etc, I will often let a tree get very oversized in a small container. A tree 6-8' tall in a pot 4-5" wide looks truly ridiculous, but do massive root surgery before planting, plant them deep and reduce the branch/leaf structure significantly before planting and it is a method for establishing larger grade trees in marginal or inaccessible sites where smaller plants might get frosted or lost in long grass.  

Bryant Redhawks comment about the first two years is spot on, don't get discouraged if there is not much above ground growth the first year!

Ben Waimata wrote:If the roots in the base of the pot are tangled I have no issues with cutting off the bottom 1-2" or even more, depending on the size of the rootball.

I do exactly this. Sometimes I also pick out the roots that are wrapped round the sides but in general those have hit the bottom of the pot and turned back up before circling the circumference, so simply chopping the bottom inch or two off has already severed these. If I think I've taken away a lot of root, I will also take some of the above ground tree/leaf, to avoid the leaf evapotranspiration outstripping the ability of the cut roots to bring in water. Consider shade or temporary repotting for a week or two between root hacking and final planting out.

I didn't mention this before but Look at all of that wonderful mycelium hyphae on those roots!

That is a very healthy set of roots and you should save all of that magnificent mycelium that falls off and incorporate it in your soil.

Redhawk

Hello! The purposes of cutting the X on the bottom, and bringing those cuts up the side, aka butterfly cut, is to prevent giredling roots. The giredling roots are developed up against the container wall, not inside the root ball. The only way giredling roots would be inside the root ball, is if the nursery that produced the tree let it go root bound in a smaller pot, then didn't butterfly cut it when up potting from the smaller container. If a nursery operated not following proper up potting procedures, they would lose there reputation quickly. Anyway the giredling roots eventually grow to choke the tree off from flow of nutrients and water. After initially growing in a container, the circling roots can eventually grow large around the lower trunk mass which is below grownd level, and those two opposing forces growing against each other, are what eventually strangles itself off from nutrients and water. The butterfly cut prevents giredling roots, by eliminating only the the roots that circle to far. This method causes the least amount of shock or root disturbance. So unless you want the stunting shock of severe root pruning, and bare rooting. I personally wouldn't do anything beyond the simple butterfly cut if the roots are obviously circling the pot.. Many species do not do well with root disturbance, and if the tree already doesn't like its graft, why give it more stress. Even if the nursery didn't  up pot properly, cutting the root ball near the core 4 ways and or splaying it open, would  risk the trees life much sooner then any giredling root. The root mass looks good, and though the roots arnt in a natural shape, its not so malformed, that the tree can't straiten it out naturally. Roots are like limbs, when roots are tiny like that, the tree will select roots that better adapt to the desired shape of its genetics withing the confines of its environment, and letting undesired roots not develop. Growing roots tips have been proven to carry a certian degree of intelligence which will quickly discover the new environment and adapt accordingly. Unnecessary cutting to the roots is the last thing I would do, and at most thin slice an X on just the bottom, if the outter roots look crisis crossed.

Just my 2 cents