Plant problems

Liriope Leaves Curling: 5 Causes and How to Fix Each One

Liriope (lilyturf, monkey grass) is one of the most reliable and widely used edging and ground-cover plants in temperate and subtropical gardens. Its grass-like evergreen foliage and spikes of purple or white berries make it a staple in low-maintenance landscaping. When the strap-like leaves start to curl, yellow at the tips, or develop streaked brown patches, one of a handful of problems is almost always responsible. This guide explains each cause and what to do about it.

1. Anthracnose

Anthracnose caused by Colletotrichum and related fungi is the most common disease problem of liriope in humid climates. It causes characteristic tan or reddish-brown lesions that run lengthwise along the leaves, killing tissue from the tip downward. Affected leaves curl, yellow at the margins, and eventually die back while remaining attached to the plant.

What you will see

Reddish-brown or tan streaks running lengthwise along leaf blades
Leaf tips die back and curl, often with a yellow halo at the advancing margin
Dead tissue appears bleached or straw-colored in the center
Small dark fungal fruiting bodies (acervuli) visible in the dead tissue under magnification
Symptoms worsen through warm, wet spring and summer weather

Why it happens

Anthracnose fungi overwinter in infected plant debris and dead leaves within the clump. Spores are released during rain and splash onto healthy leaves. Warm temperatures (24 to 30 C / 75 to 86 F) and wet or humid conditions favor infection and spread. Dense, overcrowded liriope plantings that retain moisture trap the humidity that these fungi need.

How to fix it

Cut the entire planting back to 7 to 10 cm (3 to 4 inches) above the ground in late winter or early spring before new growth emerges. This removes the bulk of the infected tissue and overwintering spores.
Rake up and dispose of all cut material in the bin. Do not compost it.
Apply a fungicide labeled for anthracnose (copper-based, azoxystrobin, or thiophanate-methyl) at the first sign of new infection in spring. Repeat every 14 days during wet weather.
Improve airflow by thinning dense clumps. Divide and replant at wider spacing.
Avoid overhead irrigation; water at the soil level to keep foliage dry.

2. Scale insects

Several species of scale insects attack liriope, including liriope scale (Odonaspis ruthae) and other armored and soft scales. They attach themselves to the base of leaves and to the crown, feeding on sap and injecting toxins that cause the leaf blades to yellow, curl, and die. Heavy infestations can kill entire clumps over several seasons.

What you will see

Yellow streaks running from the leaf base upward
Leaves curl, wither, and turn brown, starting at the tip
White, grey, or tan waxy bumps or shells at the base of leaves and along the midrib
Plants decline and thin out despite adequate water and fertilizer
Honeydew secretions and associated sooty mould in soft scale infestations

Why it happens

Liriope scale is particularly common in warm, humid climates (zones 7 to 11) and spreads on plant material, tools, and wind. Because scale insects are protected by a hard waxy shell, most contact insecticides cannot penetrate their armor. Infestations often go undetected for years because the symptoms (yellowing, slow thinning) resemble drought stress or fertility problems.

How to fix it

Cut the planting back hard in late winter to expose the scale-infested crown and leaf bases. Dispose of all cuttings.
Apply a horticultural oil spray to the crown and remaining stubs immediately after cutting to smother scale crawlers and overwintering adults.
For established infestations, apply a systemic insecticide (imidacloprid) as a soil drench in spring. The plant takes it up and the toxin reaches the scale through the sap.
Repeat the soil drench once per season for two to three years for heavy infestations.
Inspect new plants before purchase and avoid introducing infested material.

3. Root rot

While liriope is tough and tolerates a range of conditions, it will develop root rot in poorly drained soil that stays saturated for extended periods. Phytophthora and Pythium species infect the fibrous roots, causing wilting and leaf curl despite adequate soil moisture.

What you will see

Leaves yellow, curl, and pull out easily from the crown
Crown tissue is brown or black and smells sour
Roots are brown, mushy, and few in number when the plant is dug up
Entire patches of liriope ground cover thin out and die in low-lying areas
Symptoms are worst in spring after a wet winter or in low spots that hold water

Why it happens

Low-lying areas in the landscape, downspout runoff zones, and beds with heavy clay soils are most at risk. Liriope planted in these situations may look fine for several seasons before root rot becomes severe enough to cause visible symptoms. Warm, wet conditions in spring and early summer accelerate Phytophthora activity.

How to fix it

Improve bed drainage by adding raised edges, installing French drains, or incorporating coarse grit into the planting area.
Dig out dead or dying clumps and inspect roots. Dispose of heavily infected material.
Treat the soil with a fungicide drench labeled for Phytophthora before replanting.
When replanting, choose liriope varieties with better tolerance for wet conditions, or replace with a species better suited to the drainage conditions.
Do not replant liriope in the same spot without first improving drainage significantly.

4. Drought and heat stress

Established liriope is quite drought tolerant, but newly planted specimens, those in thin sandy soils, or those growing in full sun in hot climates can show leaf curl and tip browning during extended dry spells or heat waves. Container liriope is especially vulnerable since pots dry out much faster than open ground.

What you will see

Leaf tips turn brown and curl, progressing inward during dry periods
Leaves roll inward along their length in severe stress
Soil is bone dry several inches down
Plant recovers after a deep watering, though tip browning persists
Symptoms most visible in late summer when heat accumulates

Why it happens

Newly established liriope (in its first full season) has not yet built the extensive root system that gives mature plants their drought resilience. Sandy soils drain quickly and provide little moisture reserve between rains. Liriope in full sun in hot climates experiences far more water demand than the same plant in part shade.

How to fix it

Water newly planted liriope deeply once or twice a week for the first full season to encourage deep root development.
Apply a 5 to 7 cm (2 to 3 inch) mulch layer over the root zone to retain soil moisture and moderate soil temperature.
In very hot climates, plant liriope in part shade rather than full sun to reduce heat and moisture stress.
Trim browned leaf tips with scissors to improve appearance while the plant recovers.
Once established (after the first or second season), liriope rarely needs supplemental water except during extended drought.

5. Slug and snail damage

Slugs and snails feed on liriope leaves at night, leaving irregular notches, holes, and ragged edges that cause the damaged leaves to curl and dry out. While liriope is not a preferred host for most slug species, dense, moist plantings in shade provide ideal slug habitat, and feeding damage can be significant in wet springs.

What you will see

Irregular holes or notches along leaf edges, not following a lengthwise pattern
Damaged leaf edges curl and brown
Silvery slime trails on leaves and soil around the planting
Damage appears overnight and is worst after rain
Slugs or snails found hiding under the dense leaf mass during the day

Why it happens

The dense, moisture-retaining leaf clumps of liriope provide excellent hiding places for slugs during the day. Moist, shaded conditions and wet spring weather create peak slug activity. Newly emerging leaves in spring are softest and most attractive to slugs.

How to fix it

Scatter iron phosphate slug bait around the planting. It is effective, breaks down into soil nutrients, and is safe for pets and wildlife.
Apply a ring of coarse grit or copper tape around individual plants or beds. Slugs dislike crossing rough or electrically uncomfortable surfaces.
Check under the dense leaf mass during the day and remove slugs and snails by hand. Drop them into soapy water.
Avoid using excessive mulch against the crown, which provides additional hiding places.
Cut the planting back in late winter to remove the protective canopy that slugs overwinter under, exposing them to birds and cold.

Quick reference: liriope leaf curl by symptom

Symptom	Most likely cause	First action
Tan/brown lengthwise streaks, curling tips	Anthracnose	Cut back hard, apply copper fungicide
Yellow from base up, waxy bumps at leaf bases	Scale insects	Cut back, horticultural oil, systemic drench
Leaves pull out, brown mushy crown	Root rot	Improve drainage, fungicide drench
Tip curl and browning, dry soil	Drought / heat stress	Deep water, mulch, consider part shade
Ragged holes, slime trails, overnight damage	Slugs / snails	Iron phosphate bait, grit barrier

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Frequently asked questions

Why are my liriope leaves curling?

The most common causes are anthracnose fungal disease, scale insect infestations, and root rot from poorly drained soil. Liriope is tough but not immune to these problems, particularly in hot, humid climates.

Should I cut back liriope every year?

Yes. Cutting liriope back to about 3 to 4 inches from the ground in late winter before new growth emerges removes damaged, diseased, and dead foliage and lets you inspect the crown. Use a string trimmer or sharp shears.

What causes brown tips on liriope?

Brown tips on liriope are most often caused by anthracnose fungal disease, scale insects feeding on the leaf base, or physical damage from frost or drought. Check the base of the leaves for waxy scale insects before treating.

How do I get rid of scale on liriope?

Cut the plant back hard to remove the worst-infested foliage, then drench the crown and soil with a systemic insecticide such as imidacloprid. Horticultural oil spray in late winter before new growth also suppresses scale populations.

Is liriope drought tolerant?

Yes. Established liriope is quite drought tolerant and only needs supplemental watering during extended dry spells. Overwatering in clay soil is more likely to cause problems than underwatering.