In reply to Chris ]) who wrote this in
], I, Marvo, say :

Noticed this morning.
There has suddenly appeared a white deposit on an area of earth about
a yard square - underneath a silver birch (which may not be relevant).

What on earth can it be?
I don't like to even touch it without knowing.

I scraped a bit up on the tip of a stainless steel table knife - and
it seems to be about a millimetre thick - possibly some kind of
fungus - paste-like when squashed - doesn't cover the whole area -
just blotches of it on the ground.

How can I find out what it is?
Should I be concerned?
Might urgent action be needed?

Oddly, I found exactly the same thing after the heavy rain at the weekend.

It turned out, after inspection under a magnifying glass, to be tiny fungi,
like pointy mushrooms. I think they were imported with the rotted horse
manure than had been used to fill that particular hole a few weeks ago.

Nothing to worry about, but certainly not big enough for frying :-)

HTH