Question
I'm in the Dallas, TX area and I have several places in my lawn where I utilize Liriope for ground cover, borders, etc.  

I absolutely love it, but for some reason this year I seem to have more weeds in my Liriope than before.  I went to a local gardening store and asked about a weed killer I can use that won't damage the Liriope, and I was told that because Liriope is a broad-leaf plant, all weed killers will also kill it along with the weeds.

Any ideas for me?

Answer
Christina:

This question is tricky because my experience may not prove universal and I have to be sure of the plant to which you refer.

Liriope spicata or muscari is fairly hardy and, apparently resistant to small doses of a glyphosate product (Roundup etc.)  Ophiopogon, dwarf green mondo grass, a groundcover, may not be.

The weeds of which you speak are not clear either.  If they are wiregrass, creeping charlie, or other perennial creeper, spray.  If an annual or non-persistent perennial, remove by hand and thicken the stand of liriope.

As I remember, and I could be wrong, you all have had plenty of rain this year.  Different growing patterns may apply and not return.  The same could be true of an unseasonable drought.

Try a small spot with the glyphosate to see the response.  If OK after a rain, try some more.  Remember, it takes a while for this material to work, so results will not be immediate.  This is a broad spectrum, meaning it will kill anything to which it is applied.  I have noted some resistance to it in certain plants.  Euonymus and liriope among them.  But be careful and try a spot before treating the whole area.

One more trick if spraying:  immediately after application, mow the liriope fairly low.  This will remove the leaves with spray on them and keep most of herbicide from entering roots.  This is not a guaranteed method and no company would recommend it that I know of.  Caveat...

Removing it by hand is practical too.

Best wishes.