In article ,
Martin Brown wrote:
On 06/05/2015 19:59, Chris Hogg wrote:
On Wed, 06 May 2015 19:15:33 +0100, Another John
wrote:

Having recently created a new border in the grass area, I had a load of
turf to pile up. Finding nowhere else suitable in the garden, I made the
heap under an old cherry tree - I guess it's about 2 or 3 yards from the
trunk. The tree is about 100 years old I'd guess: going on for 2 foot
across the trunk.

A neighbour popped by and said I shouldn't do this: the heap will change
the soil level for the tree's feeding roots (and so will the compost
heap beside it), and ultimately this will kill the tree.

No, it won't. It is very likely to grow roots into the pile, though.
A walnut did that to a pile of mine - neither was seriously damaged
when I used the pile for loam.

I've heard it said that if you heap earth over the roots of an
established tree, the roots will suffocate and the tree will die, or
at least not flourish. I have no idea if it's true, or if it is, what
depth of earth is needed to cause the problem, but it sounds like the
same OWT that your neighbour was repeating.

I have heard it said too although I have never seen a large mature tree
actually killed by small soil level change (ISTR 4" over a wide area is
enough to cause trouble by starving the surface roots of oxygen). Trees
can easily cope with a gradual build up of leaf litter but not a sudden
artificial change in the soil level caused by human intervention.

If you cover most of the root area of a tree with impervious soil
(e.g. heavy clay), that might happen. 4" of well-drained soil
will make little difference, nor will even heavy clay over a small
proportion of the area.


Regards,
Nick Maclaren.