loose soil around tree

[gc4078]

I have an elm tree that was planted as a 24" box 2 years ago by the nursery i purchased it from. In high winds a few days ago a stake snapped and the tree fell to nearly 45 degrees and revealed that approx 12" radius around trunk is nothing but planting soil (no binding just loose airy soil). Of course the nursery will not offer any help - Moon Valley Nursery in Phoenix, az. good prices but horrible follow up service.

There is a well of about 3-4" sub-grade around the tree that is about 3 feet and I was considering digging some of the "soil" up and mixing in some native dirt and possibly bringing the well up to 1" or at grade. I am unsure how deep i can go without causing the tree any distress. Anyone have any experience with this and/or advice?

Thank you for your time,

Chris

P.S. over watering (or underwatering) is not an issue.

 

[Kneejerk Bombas]

Why isn't the loose airy soil filled up with roots? After 2 years, I'd think the planter would be filled up with roots. I'd also think the tree would be stable by now.
Try digging down until you see the root flare. This will give you a chance to see wether or not the tree is planted at the proper depth, and allow you to see what's going wrong with the roots that they haven't taken hold.
With the tree only having been planted for 2 years, and being tipped over, you might want to just remove it from the planter, get the soil the way you want, and replant it properly.