On occasion I have had potential clients call me and ask me if I can till their gardens. The short answer is no, and it's not because I can't, but because I won't. Tilling soil affects soil structure which has a major influence on water and air movement, biological activity, root growth and seedling emergence. Watch this short video by the U.S. Department of Agriculture: (June 29 post)
Have you ever considered adding native plants to your garden? They are excellent choices as they have naturally survived and thrived in our climate as well as providing a food source for native fauna.
Better Homes & Gardens have compiled 15 native plants for our region, and with the exception of Idaho Fescue (zone 5), they are great choices for Calgary gardens.