What is over your septic tanks?
I have tried the following
grass - did great until it got really hot and then there were 3 round dead spots in the yard
sedum - a little better than grass, but hard to keep weeds out
morning glory grown on a teepee trellis over the tanks - they did great but weeds went wild inside the teepee.
Then I decided phooey on growing stuff and covered it with gravel and a few big rocks to make a dryscape. Worked great until we had to have the tanks cleaned out, and then what a mess
Currently I have big pavers over it just so I can see where it is when I'm mowing (one lid is cracked from a long horn stepping on it) so I won't drive over it.
There has GOT to be something that looks good and is easy to get to the tanks.
But what is it?