Liriope, commonly known as lilyturf or monkey grass, is a popular, low-maintenance perennial often used as a groundcover or border plant. It is valued for its dense, grass-like foliage and its ability to thrive in a variety of conditions, from sun to shade. Knowing the correct time and method for cutting back the old foliage is important for maintaining its health and attractive appearance. A well-timed trim removes tattered, winter-damaged leaves and encourages a flush of vibrant new growth in the spring.
The Ideal Timing for Pruning
The most effective time to cut back liriope is during its dormant period in late winter or very early spring, typically January through early March. This timing is optimal because the plant is not actively growing, which minimizes pruning stress. The goal is to remove the old, brown, or tattered foliage before new, bright green shoots emerge from the crown.
Waiting until the plant is fully dormant prevents the removal of insulating foliage that protects the crown from extreme cold. Cutting back too early in the fall or mid-winter can expose the plant’s base to potential freeze damage. The window for pruning closes quickly once the weather warms and the plant breaks dormancy.
If pruning is delayed until after new growth has started, the fresh, tender leaves will be cut along with the old foliage. This results in an unsightly, “chopped” look with blunt, squared-off tips on the new leaves. This appearance can persist until the plant grows out of it later in the season, so monitoring for the first signs of new growth determines the final deadline.
The Proper Cutting Technique
The cutting process requires attention to the plant’s crown, the point just above the soil line where new leaves emerge. The ideal cutting height is between four and six inches above the ground, ensuring the crown remains undamaged. Cutting too low risks injuring the growth point, which severely hinders the plant’s ability to regenerate.
For large areas, a lawnmower set to its highest blade height can quickly shear the foliage, provided the blades are sharp. For smaller borders or clumps, tools like sharp hedge shears, hand pruners, or a string trimmer are more manageable and allow for greater precision. Using sharp tools creates clean cuts, which reduces the chance of disease entering the plant tissue.
After cutting, rake and remove all old debris from the planting area immediately. This cleanup step prevents the development of fungal diseases, such as anthracnose, which can harbor in decaying leaves. Removing the old material allows sunlight and air to reach the crown, promoting a healthier and more vigorous start for new spring growth.