Posted: 14/06/2014 at 20:19
Incorporate as much organic matter as you can into the soil, farmyard manure, leaf mould, garden compost etc - you'll find that worms will soon appear in your garden.
When we came here the soil was dry and thin and there were very few worms. Three years of doing the above and whenever I turn any soil there are several worms to be seen.
Whether your soil is thin and gritty or heavy clay, incorporating organic material will improve the fertility and drainage and increase the worm population.