Hungry earth

SIR – Sarah Knapton writes of digging Y-fronts into the ground to test the quality of the soil (report, November 3).

I was once advised to clean, by burial, a Pyrex dish thickly coated with burnt pudding. Into the rose bed it duly went. Some months later, I recovered it. There was not a trace of pudding was to be found. However, the surface was badly pitted. Very hungry microbes must live there, giving me beautiful roses.

Mary Follows

Calverley, West Yorkshire