I am renting a townhouse that has a 4X4 foot square plot of dirt in the backyard next to our stone work patio. The dirt has some "crab grass" looking plants that are dieing. I am a looking for some cheap ideas for low maintenance, cheap way to make this dirt pile look pretty and calm down the dust. I have a toddler so needs to be kid safe.

I love the idea of a garden or flowers, but we have a large oak tree covering our small patio. so it needs to be ok for shade.

Please help!