Hi

For the last couple of years in the rockery there has been a strange growth on the soil. I get rid of it but it doesn't take too long to come back. The soil doesn't get too much direct sunlight which I think is partly the problem. Does anyone:

a) Know what it is
b) Know how to get rid of it?! There are a number of established plants already growing so it would need to be without harming these.

Any advice gratefully received. Thanks in advice

Matt