It's one of those "If you build it, they will come" things. By adding any organic matter to your soil, you encourage local earthworms to move in, aerate and fertilize your soil. Make compost. Start lasagna beds. Throw you used coffee grounds on your flower beds. Use organic mulches, like leaves or straw or grass clippings. Collect fall leaves from your neighbors and use them as soil ammendments. ... Once you build up your soil it will be alive with worms. It's not a one time thing, but rather an ongoing process.
After gardening and composting in this yard for over 30 years, my once dead, light tan mucky clay soil is now rich and black with a massive network of worm tunnels.
Karen
