Our north-Florida backyard has a fairly steep slope... what I call "the
hill". When we moved into our home about four years ago, "the hill"
had a fresh layer of Centipede grass (from sod) growing on it.
However, over the last few years, whenever I get some grass die-out I
quickly get erosion problems. I've backfilled parts of my hill with
some the best Florida "topsoil/black dirt", but for a large section of
the hill it's to no avail. Enter Saint Augustine. With it's deep root
structure, I'm thinking, and hoping, it'll "stick" to the hill much
better than Centipede.

1) Is my thinking correct?

2) And, if so, how will the Saint Augustine "mix" with Centipede? Will
the two varieties look okay mixed or next to each other?

Notes:
- I fertilize the hill once in late spring/early summer with a light
application of 15-0-15.
- The hill gets a mininum of foot traffic.
- The hill gets sunshine all day long.
- The hill doesn't get a lot of supplemental water. I only water it
when things start to get really dry.

Thanks in advance,
Patrick