There is a large mound of dirt in the back corner of my garden (probably 250-300 square feet in total). The base of this mound is a few large boulders that were pulled up when digging a hole for the basement when the house was being built. The rest of the pile is a mix of sandy soil and small/medium rocks. I've ignored it for the last couple of years and it's now covered in a think layer of leaves, with the occasional weed popping through. It looks pretty terrible.

I would like to clean this area up and plant some sort of ground cover or creeping plant. I don't want something particularly tall, as I think it would look cool if some of the larger rocks are popping up between the plants. I honestly don't care what it looks like or if it flowers. I just want a plant that will be able to withstand (or event thrive) in the less than ideal conditions.

The area gets morning sun/afternoon shade (zone 6a). I don't mind watering during the first few months after planting to help get established, but I would like something that is extremely low maintenance (or preferably non-maintenance) after the first year. I don't mind some mild invasiveness as this area isn't near any other gardens but I don't want something so invasive that it starts popping up in the lawn.

Any ideas would be greatly appreciated!