How To Remove St. Augustine Grass: Step-by-Step Eradication And Soil Prep Guide

Eradicating St. Augustine grass requires targeting its extensive, surface-level network of creeping stems, known as stolons, which root rapidly at every node. To completely remove St. Augustine grass, you must either mechanically extract the root-and-stolon system to a depth of two inches using a sod cutter, or chemically neutralize the active growth with targeted non-selective herbicide applications over a 14-day cycle. Choosing the correct strategy prevents stubborn regrowth and prepares your soil matrix for seamless re-landscaping.

Pre-Removal Planning and Tool Checklist

St. Augustine grass (Stenotaphrum secundatum) is a coarse-textured, warm-season turfgrass known for its aggressive lateral growth. Because it spreads almost exclusively via above-ground stolons rather than deep underground rhizomes, complete physical removal is highly achievable if you systematically extract the stolons. However, skipping preparation steps or leaving fragmented nodes behind will guarantee rapid re-establishment.

Before selecting an extraction method, you must evaluate your site's soil compaction, moisture levels, and the proximity of desirable vegetation. Preparing your workspace and gathering specialized tools beforehand minimizes physical labor and prevents structural damage to your soil profile.

Required Materials and Equipment

• Mechanical Extraction Gear: Heavy-duty kick-type or motorized sod cutter (rental highly recommended for areas over 500 square feet), sharpened square-point spade, and a heavy-duty steel garden rake.
• Chemical Application Kit: 41% Glyphosate concentrate, non-ionic surfactant (to help the herbicide penetrate the waxy cuticle of the grass blades), hand-pump or backpack sprayer with a fan nozzle, and personal protective equipment (safety glasses, chemical-resistant gloves, long sleeves, and closed-toe boots).
• Solarization Materials: 2 to 4 mil thick clear UV-stabilized polyethylene sheeting, heavy garden staples, and utility soil bags or bricks to weigh down edges.
• Soil Amendment Supplies: Organic compost, rotary tiller (optional), and pH testing kit.

Prerequisite Standards and Project Benchmarks

• Soil Moisture Target: The soil must be moist but not saturated. Dry clay or sandy soils will ruin sod-cutter blades and make manual digging impossible, while muddy soil leads to severe compaction. Irrigate the target area with 0.5 inches of water 48 hours before physical excavation.
• Weather Conditions: For chemical and solarization methods, wait for consistent daily temperatures above 80°F (27°C). Herbicide absorption relies on active plant transpiration, while solarization requires intense, direct sunlight.
• Project Budget: $50 to $150 for chemical or solarization methods; $150 to $350 for motorized sod cutter rental and disposal fees.
• Estimated Duration: Mechanical excavation takes 1 to 2 days; chemical eradication requires 10 to 14 days; solarization takes 6 to 8 weeks.

Step-by-Step Eradication Workflows

Method 1: Mechanical Sod Cutting (Fastest Physical Extraction)

This method is ideal for homeowners looking to install new sod, seed, or hardscaping immediately after removing the St. Augustine turf.

Step 1: Flag Utilities and Prep the Turf

Locate and flag all shallow irrigation lines, sprinkler heads, outdoor low-voltage lighting wires, and shallow tree roots. Mow the St. Augustine grass to its lowest possible setting (around 1 to 1.5 inches) and bag the clippings. This reduces the bulk material you must cut and roll.

Step 2: Set the Sod Cutter Depth

Adjust the blade depth on your motorized sod cutter. To successfully remove St. Augustine grass without stripping away all your valuable topsoil, set the blade to cut exactly 1.5 to 2 inches deep. This depth easily slices beneath the crown and stolon layer where the root mass is concentrated.

Warning: Setting the sod cutter blade shallower than 1.5 inches will leave live crown tissue behind, resulting in rapid stolon regrowth. Setting it deeper than 2.5 inches makes the cut sod rolls incredibly heavy and difficult to lift, while unnecessarily stripping away fertile organic topsoil.

Step 3: Cut and Strip the Turf

Position the sod cutter at one corner of your yard. Engage the blade and drive the machine in straight, parallel lines across the lawn, making long passes. Slice the turf into manageable strips. Using your spade, cut the long strips into 3-foot to 4-foot sections, roll them up tightly with the dirt side facing outward, and stack them on a wheelbarrow for disposal or composting.

Step 4: Rake and Extract Remaining Stolons

Use a heavy-duty steel garden rake to aggressively scarify the bare soil surface. Manually pull up and discard any loose stolons, root fragments, or runners left behind. St. Augustine stolons can regenerate from fragments as short as two inches if they remain in contact with damp soil.

Method 2: Chemical Eradication (Low-Impact Root-and-Stolon Neutralization)

Chemical eradication is the most effective way to kill the root system completely without disturbing the soil structure or bringing dormant weed seeds to the surface.

Step 1: Allow Active Growth and Hydration

Do not mow the St. Augustine grass for at least 7 to 10 days before applying herbicide. This allows the leaf blades to grow long, maximizing the surface area available to absorb the chemical. Water the lawn lightly 48 hours prior to application to ensure the grass is actively growing and not under drought stress, which can cause the plant to shut down its circulatory system and resist herbicide uptake.

Step 2: Calibrate and Mix the Herbicide

Mix a non-selective herbicide containing 41% Glyphosate. Add 2 to 2.5 fluid ounces of glyphosate concentrate per gallon of water inside your sprayer. To ensure the chemical penetrates the thick, waxy cuticle of the St. Augustine blades, mix in 1 to 2 teaspoons of a non-ionic surfactant per gallon of spray solution.

Pro-Tip: Apply the herbicide on a calm, windless morning when ambient temperatures are between 70°F and 85°F (21°C to 29°C). High winds cause drift that can kill neighboring landscape plants, while temperatures above 90°F can cause the herbicide to evaporate before the leaves absorb it.

Step 3: Apply the Spray and Monitor

Spray the turf evenly until the foliage is wet but not dripping. Avoid walking through the wet herbicide to prevent tracking the chemical onto desirable parts of your landscape. Keep pets and children off the treated lawn until the spray has dried completely (usually 2 to 4 hours).

Step 4: Execute a Secondary Touch-Up Application

Within 7 to 10 days, the St. Augustine grass will turn yellow, wilt, and begin to brown. Inspect the area for any resilient green patches, especially around edges, fences, or concrete walkways where spray coverage might have been uneven. Spot-treat these surviving patches with a second application of the glyphosate mixture to ensure total root kill.

Step 5: Scalp and Clean the Soil

Once the entire lawn is completely brown, dry, and dead (typically 14 days after the first application), mow the dead turf at your mower’s lowest setting to scalp it. Rake away the dead organic matter to expose the bare soil below.

Method 3: Soil Solarization (Organic Heat Sterilization)

Solarization uses heat from the sun to cook the St. Augustine grass and sterilize the upper layer of soil, destroying weed seeds, pathogens, and turf roots without chemicals.

Step 1: Mow and Irrigate the Target Zone

Scalp the grass as close to the soil surface as possible using your lawnmower. Remove all clippings. Thoroughly saturate the soil down to a depth of 6 inches by running a sprinkler over the area for several hours. Wet soil conducts heat much more efficiently than dry soil.

Step 2: Lay the Clear Sheeting

Lay a 2 to 4 mil thick, clear, UV-stabilized plastic sheet directly over the wet, scalped grass. Do not use black plastic; black plastic absorbs heat itself rather than transferring the sun's infrared rays directly into the soil.

Step 3: Create an Airtight Seal

Dig a shallow, 4-inch deep trench around the entire perimeter of the treatment area. Pull the clear plastic sheet tight across the soil, place the edges into the trench, and bury them under heavy soil. Weigh down the rest of the edges with sandbags or bricks to prevent wind from lifting the plastic and releasing trapped heat.

Step 4: Let the Solarization Bake

Leave the plastic in place for 6 to 8 weeks during the hottest summer months (June through August). The air temperature beneath the plastic will rise above 140°F (60°C), completely baking the St. Augustine stolons and roots. Once the grass is bleached-white and brittle, remove the plastic and rake away the dead debris.

Comparative Analysis of St. Augustine Eradication Techniques

The table below outlines the performance metrics, physical requirements, and technical trade-offs of the three primary removal methods. Use this data to determine the best approach for your specific landscape conditions and timeline.

Mitigating Post-Removal Failures and Stolon Regrowth

Scenario 1: Persistent Regrowth from Left-Behind Stolon Segments

• Root Cause: The sod cutter was set too shallow, or manual raking failed to remove fragmented nodes. These stolons quickly re-root in damp soil.
• Actionable Fix: Spot-treat any emerging green shoots immediately with a directed application of 2% glyphosate solution. Do not hand-pull these shoots, as they often snap, leaving root fragments that will simply grow back.

Scenario 2: Severe Erosion and Soil Runoff After Mechanical Stripping

• Root Cause: Stripping the sod leaves loose, exposed topsoil vulnerable to heavy rains or wind, leading to erosion and nutrient loss.
• Actionable Fix: Immediately cover the bare ground with a thin layer of organic compost or straw mulch. If you plan to lay new sod or seed, install it within 48 hours of mechanical removal to stabilize the soil matrix.

Scenario 3: Off-Target Herbicide Damage to Nearby Landscape Plants

• Root Cause: Fine mist drifted onto neighboring flower beds, or the herbicide washed from the grass blades into the root zones of adjacent ornamental trees during heavy rain.
• Actionable Fix: If drift occurs, immediately rinse the foliage of the affected non-target plants with clean water to wash away the glyphosate before it can penetrate the leaves. Next time, use a cardboard drift shield or apply the herbicide using a paint roller on the lawn edges.

Frequently Asked Questions

Will vinegar or boiling water safely kill St. Augustine grass?

Household vinegar (5% acetic acid) and boiling water only act as contact herbicides, burning the leafy green blades without damaging the deep root systems or tough stolons. The grass will quickly sprout back from its subterranean crowns. To kill St. Augustine grass organically without synthetic chemicals, you must use clear plastic solarization or mechanical sod removal.

How soon can I plant new turf or garden beds after using glyphosate?

You can safely plant new grass seed, sod, or ornamental plants 7 to 10 days after your final herbicide application. Glyphosate binds tightly to soil particles and becomes inactive once it hits the ground, meaning it will not be absorbed by the roots of your new plants. Always ensure the existing St. Augustine grass is completely dead before planting to prevent the old turf from contaminating your new landscape.

Can I just lay new topsoil and a different grass variety directly over my existing St. Augustine lawn?

No. Laying topsoil or different sod directly over St. Augustine grass will not smother it. St. Augustine is highly aggressive and will grow straight up through several inches of new soil or compost, contaminating your new lawn and creating an uneven, patchy mixture of different grass types. You must completely eradicate the St. Augustine grass before installing any new turf or plants.

What is the best way to handle the discarded sod after stripping it?

You can compost stripped St. Augustine sod if your compost pile reaches and maintains internal temperatures above 140°F (60°C) to kill the stolons and seeds. If your compost pile is too small to reach these temperatures, dispose of the sod rolls at a local green-waste facility or bury them deep in a trench covered by at least 12 inches of compacted soil to prevent regeneration.

Revitalize Your Soil and Landscape

Once you have successfully removed your stubborn St. Augustine grass, your bare soil is ready for a fresh start. Take this opportunity to amend the ground with premium organic compost and perform a comprehensive soil test to guarantee your new lawn or garden thrives.