I have a small area that I need to fill in. I am weary about tilling so as to not stir up old seed like I did in the back landscape bed. I have cardboard from my move that I'm going to put over the area and already have some mulch, compost and soil to put over the top. I'm planning on putting 4 0'clock seed down in this area. Will this work? My hopes are that by the time the roots get down as far as the cardboard it will have already started decomposing. Everywhere I have dug in this yard I've come up with tons of worms, at least 2-3 for every hole I've planted in, front and back yards. I don't imaging this area would be any different and the soil is already unbelievable for this area, nice, dark and rich. Does anybody forsee any problems with this plan, aside from the typical 4 o'clock problems, which I'm happy to handle and have room to expand when needed.