Here is my dilemma. I have an established flower bed. I have always mulched it every year. I do not like edging material, bricks, rocks, plastic edging, etc. I just like the deep edge between the grass and mulch. I never knew exactly how to do this and always used my edger, but it was never deep enough. So anyway, I finally figured out how to make a trench (easy I know). The problem I have is I JUST put in new mulch. However, I don't have a problem adding more cuz I still have some oak tree leaves falling in the bed that I want to cover since they are finished falling. Anyway, what I have done so far is rake up some of the mulch forward so I can have enough room to make a trench. Can I mix the soil that I dig up into the mulch that I already have and then add the new bags of mulch on top of that? Does that make sense?