Answer: Moss indicates the soil is acidic, drains poorly, and is shady. You can apply lime to help sweeten the soil. While you're at it, try digging in some organic matter to facilitate better drainage. As you're moving, adding, or dividing your plants, mix in additional organic matter. It will take a few years before you change the soil's texture, but in a few short years you'll have rich garden loam that's less acidic than it is now.
Best wishes with your flower bed!
Q&A Library Searching Tips