How to understand if my tree's roots are girdling

Question

Some time ago I planted the dwarf (M27) apple tree shown and described in this question. At the time of planting, I am afraid I didn't dig a very wide hole, just twice the lateral size of the pot in which it came in. Also, the soil here is very heavy clay, therefore I am seriously worried that the tree's roots might be girdling in the future, just moving in circles in the clay "prison". The tree is grafted on a dwarfing rootstock M27, and when I planted it (1 month ago) it was 2-year old.

1. What are symptoms that can tell me if the roots are girdling?

2. Is there anything I can do to actively check? And what would be the best season to do that?

Answer 1

Girdling as an expression is used in two ways regarding trees - first is girdling of the trunk deliberately, above ground, often done to kill trees, or inadvertently by leaving ties in place too long; the second is when the roots, or a root, encircle the trunk below ground and gradually strangle it, and that's the form of girdling you're worried about in your situation. It's much better to try to correct any possible problems now, as you've so recently planted, rather than waiting to see symptoms in a few years.

Link below gives quite a lot of information as to how to plant a tree to try to avoid this form of girdling - in your current circumstances, you've said the soil is heavy clay, and you only dug an area twice the size of the rootball. In the information below, you will see that the most critical thing to make sure of to avoid girdling is the level at which the tree is planted, that is, the rootball must not be planted too deeply. If you have planted it too deeply, you may need to remove it and replant a bit higher.

It will likely pay you to immediately rototill (or just dig) the surrounding area where you've planted the tree to a width of 3 or 4 times the size of the existing rootball, given that your soil is heavy clay, possibly compacted, and may be very wet at times. This method is described under Section 2, Modification for Compacted Soils, but its probably worth scanning through the whole document anyway, to check whether you needed to leave the rootball slightly proud of the soil. If you feel you have planted too deeply, its only been a month since you planted and is therefore not too late to take it out and adjust the hole, making it a saucer shape rather than straight sided, as demonstrated in the article. Wider rototilling of the area is best done once the tree is planted anyway.

http://www.ext.colostate.edu/mg/gardennotes/633.html

UPDATE

Having looked again at your post about this tree back in September, if that's an allotment you've planted it in, it looks as if you have previously dug all the soil over at some point in the last year or months, so I don't think you have a problem unless you planted the tree too low...

Answer 2

Well girdling and getting root bound are two different things.

Girdling is when the bark is damaged, torn away or constricted so that nutrients can no longer flow.

What you are describing is being root bound.

In my previous location in Iowa in the Mississippi River Valley we had very clayey soil along with a dolomite hard pan just a few feet down. I planted pretty much the way you did, but nearly all of my tree plantings were bare root stock. With these I didn't seem to have a problem with the clay at all. A potted tree that's already root bound before planting in the ground may have difficulty breaking free of the pattern. If you carefully broke up the outside of the root ball and trimmed the roots properly and ensures good root spread during the planting, then I think you should be just fine. You do have trees around you right? So you'll be fine. Once the tree has been in place for a full year is usually when you can stop worrying so much.