On Tue, 30 Jun 2009 10:08:14 +0100, June Hughes wrote:

all I could see was a little compost
and a huge mass of thin, white roots. I have never seen so many when
harvesting potatoes in the conventional manner. Can anyone advise
please? If there are no potatoes, it is too late now but I wonder where
I have gone wrong. The compost and weeds are compacted, so it is only
possible to scrape out a little compost before coming to a halt.

Contrary to common sense, potato tubers are not found in the roots. They
are, biologically, modified shoots, hence the earthing up. Look above the
roots! Good luck.