How To Get Rid Of Monkey Grass Permanently: A Comprehensive Removal Strategy

Eradicating monkey grass (Liriope muscari and Ophiopogon japonicus) requires a combination of mechanical excavation and systemic chemical intervention to neutralize its resilient, tuberous root system. Because these plants propagate through aggressive rhizomes and deep-seated fleshy tubers, complete removal hinges on total root extraction or precise translocated herbicide application during the peak vegetative growth cycle.

Strategic Preparation and Site Assessment Requirements

Successfully removing monkey grass is an endurance task that depends on identifying the specific variety—border grass (Liriope) versus mondo grass (Ophiopogon)—and assessing the density of the infestation. Before initiating the removal, you must evaluate whether the plant is encroaching upon sensitive ornamental landscape beds, lawn areas, or hardscape foundations.

• Essential Equipment: A heavy-duty flat spade or trenching shovel, a garden fork for root aeration, a mechanical sod cutter for large-scale infestations, high-concentration glyphosate or specialized grass-selective herbicides, and heavy-duty contractor bags for debris removal.
• Mandatory Standards: Removal must occur when the soil has adequate moisture to keep root structures intact but is not saturated; saturated soil prevents clean extraction of the rhizomatous network.
• Estimated Benchmarks: Small patches (under 10 square feet) can be addressed in approximately two hours. Large-scale turf replacement or bed clearing may require a multi-phase approach over 3 to 6 weeks to account for dormant tuber regrowth.

Systematic Excavation and Chemical Eradication Workflow

Step 1: Manual Site Preparation and Top Growth Removal

Before digging, shear the monkey grass foliage down to within two inches of the soil surface using a string trimmer or hedge shears. This allows you to visualize the crown structure and provides better access for your spade. If the grass is growing in a defined bed, use your spade to slice a perimeter around the target area to prevent lateral root disturbance of surrounding desirable plants.

Step 2: Excavation of the Rhizome Matrix

Begin by inserting a sharp spade at a 45-degree angle approximately six inches outside the visible clump. Push the spade deep into the substrate to sever the primary rhizomes. Use a garden fork to lift the soil and root mass gently. Avoid pulling on the tops of the grass, as this often snaps the foliage away from the tubers, leaving the regenerative nodes buried in the soil.

Warning: You must remove the entire tuber. If you leave even a small segment of the fleshy root, the plant will utilize its internal energy reserves to sprout anew within 14 to 21 days.

Step 3: Targeted Herbicide Application for Stubborn Regrowth

After the primary excavation, monitor the area for seven to ten days. Any green shoots that emerge represent missed root segments. At this stage, spot-treat the new growth with a non-selective, systemic herbicide containing glyphosate. Apply the product directly to the leaves of the new shoots using a handheld wick applicator or a fine-mist sprayer. The herbicide will translocate down into the remaining tuber fragments, killing them at the source.

Step 4: Soil Solarization and Post-Procedure Stabilization

For heavily infested areas where manual removal was incomplete, apply clear plastic sheeting over the site for 4 to 6 weeks during the summer. The greenhouse effect will elevate soil temperatures to levels that denature the protein structure of any remaining monkey grass rhizomes. Once the area is cleared, replenish the soil with organic matter and cover with a 3-inch layer of hardwood mulch to suppress any dormant seeds or missed segments.

Comparative Analysis of Monkey Grass Mitigation Techniques

Addressing Recurrent Infestations and Field Failures

• Root Fragmentation Failure: If you notice small, isolated sprigs appearing in the weeks following removal, it indicates the original excavation left behind fractured rhizomes. Actionable Fix: Do not dig again immediately; wait for the shoots to produce at least 3 inches of leaf surface area, then apply a targeted systemic herbicide to ensure the chemical reaches the root system.
• Contamination of Flower Beds: If monkey grass has migrated into thick perennial clumps, digging will destroy your desired plants. Actionable Fix: Use a paintbrush to carefully "paint" glyphosate onto the monkey grass leaves, avoiding any contact with the foliage of your permanent ornamental plants.
• Rebound from Soil Banks: In scenarios where monkey grass is adjacent to a slope, rain often washes new propagules into the cleared zone. Actionable Fix: Install a physical landscape edging or a root barrier at least 6 inches deep between the infestation source and the cleared bed to prevent re-colonization.

Frequently Asked Questions

Will mowing alone kill monkey grass?

No, mowing is ineffective. Monkey grass is a clumping or spreading rhizomatous perennial that thrives on regular trimming. Mowing only removes the photosynthetic surface area, leaving the energy-dense roots fully intact to continue expanding.

What is the best time of year to remove monkey grass?

Late autumn or early spring provides the best window for removal. During these periods, the soil is typically easier to work with, and the plant is preparing for or recovering from dormancy, making it more susceptible to chemical treatments if mechanical removal fails.

Can I compost the removed monkey grass?

Do not compost monkey grass. The rhizomes and tubers are extremely hardy and can survive standard residential composting processes. Always dispose of the excavated plant material in municipal yard waste bins or seal it in dark plastic bags to dry out completely before disposal.

Will vinegar kill monkey grass effectively?

Vinegar (acetic acid) is a contact herbicide that only kills the green foliage it touches. Because monkey grass relies on deep, fleshy tubers for survival, vinegar will fail to reach the roots, and the plant will recover within a matter of days.

Professional Landscape Maintenance Recommendations

To ensure your landscape remains free of invasive Liriope species, implement a biannual inspection schedule of your garden edges. Should you require professional intervention to restore your beds to their intended design, contact a local turf management specialist to discuss selective herbicide programs and mechanical restoration options.