I would dig and amend the area for best growth.

Mine took off and spread nicely once I moved it to an area between 2 pine trees in my frontyard. They will spread better with 'some' sun, like that you'd get under tall trees. Make sure that you don't disturb them after they're planted because they send out runners and that is how they spread. I took a hand cultivator and 'roughed' up the soil a bit before transplanting them. Then used a spray bottle to water so I wouldn't disturb the new roots. They've settled in to the point that I don't have to water them with a spray bottle anymore. Btw, it has been my experience that they prefer shallow planting...don't 'bury' the main root mass too deeply but make sure all roots are covered in soil and use your fingers to tamp down the soil at the base of the plant well.

Good luck.