My front garden has been covered with red chippings for many years but I am now creating a border. The I have dug the area in question, the soil breaks up reasonable well but is sticky and has slight signs of clay and I have some good soil (from under a lawn in the back garden) to top it off with a covering of about 4". I am hoping for suggestions regarding treatments for the soil before planting. I had thought of Grow More but don't know if that would be right. I don't want to use manure as planting will be mixed and not all will cope with manure. Any advice would be very helpful.