Problems of Liriope

Plants turn Yellow - Frost Damage
Blue lily-turf plants caught by a late spring frost suffer leaf discoloration, and they are slow to recover.

Leaf Tips Brown - Alkaline or Waterlogged Soil
If planted in soil that is too wet or loaded with salts, leaf tips of Blue lily-turf turn brown. Improve drainage by adding lots of organic matter, replant in raised beds, or transplant to a more fertile site.

Leaves Scarred - Slugs and Snails
Slugs are essentially snails without shells. Usually 1 to 2 inches long, these nuisances may be white, gray, yellow, or brown-black. They have fleshy, slimy bodies and leave a telltale trail of slime wherever they travel. Although Blue lily-turf plants are virtually problem-free, slugs and snails sometimes feed on their foliage, chewing ragged sections out of leaves. Partial to moist, well-mulched beds and acidic soil, slugs and snails hide under plant debris during the day and feed on nearby plants at night. They're most destructive during rainy spells.
Trap slugs and snails with commercial or homemade traps. Fill a slug trap or shallow dish with beer and set it in the garden. Attracted to the yeast in the beer, the pests will climb in and drown. Set traps as early in the season as possible, 3 to 4 weeks after the last frost in spring. When you catch your first slug or snail, increase the number of traps to catch others before they get out of control.
For more information see file on Dealing with Slugs and Snails.

Small Brown Bumps on Foliage - Scale Insects
Scale insects form groups of small bumps or blister-like outgrowths on plant stems and leaves. These are waxy shells that protect the insect feeding beneath. The shells may be white, yellow, or brown to black, and are about 1/10 to 2/5 inch in diameter. The first sign of a scale attack is often discoloration of the upper leaf surface, followed by leaf drop, reduced growth, and stunted plants. Heavy infestations kill plants. Some species excrete honeydew, which coats foliage and encourages ants and sooty mold growth. Scale outbreaks can be triggered by pesticides used against other pests or by environmental stresses such as too much or too little water. Overuse of nitrogen fertilizer encourages the growth of scale populations. Avoid this by using a slow-release nitrogen fertilizer.
Scrape minor scale infestations off plant surfaces with a fingernail or a cotton swab dipped in rubbing alcohol. Spray heavily infested plants with a mixture of alcohol and insecticidal soap every 3 days for 2 weeks. Add one tablespoon of alcohol to a pint ready mixed commercial insecticidal soap

Blue lily-turf has no serious disease problems.