@Kellyl, if your red clay is like mine here in NE Mississippi, it is basically good for absolutely nothing. About the only things that can grow roots through it are trees (think oak and cedar). When it is wet, it is like thick, gooey mud and when dry, it is as hard as concrete. Nothing, and I mean nothing drains through it. I could dig a hole 10' deep (and still be in solid clay), fill it up with water, and use it as a swimming pool..........no liner necessary.
I use hardwood mulches in all my beds and it typically will break down to compost every year. Worms seem to love it when it breaks down, layer upon layer. I have never used pine mulch but I assume it breaks down similarly to hardwood.
