(Iggy555) in
:

I planted liriope muscari, "blue lilyturf," in the spring. They
established well, but every so often one of them will turn brown. A
couple died off, some maybe have half the clumps turn brown. It
starts as yellowing of some leaves, then quickly spreads to more of
the plant until quite a lot of it is brown. A couple of the plants
get hit directly by water, which I'm wondering if that could be
rotting it or something, but they really don't get an unusually high
amount of water compared to any other plants in my yard. Another
thought I had is that they are planted amongst a groundcover
(moneywort) and perhaps the roots of that are suffocating them or
something like this? It is also very hot here right now (I'm in S.
California, about 30 miles inland w/ only very minimal coastal
influences), so perhaps the sun is messing with them. But then, why
would only a few be affected and most look perfectly healthy. The
only other thought I have is perhaps soil condition or some kind of
fungus. Unless some were just planted badly, but if that were the
case, wouldn't they have degenerated a long time ago instead of
waiting to get established first? Anyway, I'm confused and would
appreciate any help so I can save these plants from getting worse. .
.btw, the ones that do brown. ..should I just cut away the dead stuff
or leave it until right before next spring? I'm thinking perhaps if I
cut away the dead stuff this could somehow encourage more dead stuff
to occur. ..who knows. . .I need help here!

took some googling to find this guess (!),
http://mrec.ifas.ufl.edu/jos/liriope2.htm
but maybe you can investigate this further