On 16 May, 14:22, Simon Harding wrote:
Can a tree and a vegetable plot have a symbiotic relationship?
In terms of the tree, the veg plot will absorb moisture and nutrients
before they have filtered down to the trees roots and may cause problems
with the tree. Raised beds will stop any work on the veg patch
disturbing the high level fibrous roots of the tree that are intended to
catch moisture but will further preclude the moisture reaching the tree.
Crowning out the tree will increase vigour and it will want more
nutrients and water.

I thought about doing this last year at my cousin's house and I came
up with the same answer as you. The tree seek water and the roots will
keep going till they find it. Either the tree will increase in vigour
(in my case there's 3 trees) or it will die. On site, our landscapers
always barricade around the trees twice the hight of the tree to make
sure nothing is either dumped or placed around the trees for long. 90%
of tree roots are in the top 600mm of soil. Roots extend horizontally
as far as the tree is tall (and not down as most people think).

I have since given up trying to find a solution for my cousin's veg
beds under the trees. She'll just have to walk further down her garden
to harvest her vegs.