When a plant is rootbound in a pot, where did the soil go that was originally in he pot?

Question

When a plant is rootbound in a pot, where did the soil go that was originally in he pot?

In: 81

Answer 1

A combination of compressed, decomposed and absorbed, or washed out the drainage holes in the bottom after watering.

Its also worth noting that a lot of times a rootbound plant is forming more a “cage” of roots rather than a solid lump. Roots spread out primarily, hit a wall, and then start going around rather than back inwards, so a lot of the original soil is likely inside the rootball still.