at the end of the driveway there are two big rocks one on each side. there was mulch (the mulch was from trees that the developer shredded so there was a lot) around the rocks previously and i dug up the mulch and filled in with dirt around the rocks. However there is still some mulch beneath the dirt that i put down. my plan is to plant grass around the rocks in the spring then edge a perfect circle and fill it in with dark mulch and plant flowers around the rocks. my question is: will the flowers be able to grow appropriately since there is some mulch beneath the dirt? while we are at it how can i edge a perfect circle? keep in mind i have an edger on my string trimmer and not a big machine. thanks!