earthworms can 'improve' soil - they tunnel for a living, thus loosening / aerating the soil and of course there's the castings.
you can 'add worms' to help - but not by simply dumping them on unsuitable ground.
in a heavy clay soil you'll need to work vegetative matter into the soil for them to eat - obviously they don't take up residence in places where there is no chow.
they avoid sandy soils that dry out, also places that swamp / stay too wet. |