Step-by-Step Maintenance Procedures for Grass That Spreads

The Double-Edged Sword of Spreading Turfgrasses

Turfgrasses that spread laterally—via above-ground stolons or below-ground rhizomes—are the ultimate self-repairing lawns. Varieties like Bermudagrass, St. Augustine, Zoysia, and Kentucky Bluegrass can recover from heavy foot traffic and pet damage by filling in bare spots naturally. However, this aggressive lateral growth requires strict, step-by-step maintenance procedures to prevent the grass from invading flower beds, choking out adjacent landscaping, and building up a suffocating thatch layer.

Managing grass that spreads is not about stopping its growth entirely; it is about directing its energy downward into the root zone and laterally within defined boundaries. Below is a comprehensive, step-by-step maintenance protocol designed specifically for stoloniferous and rhizomatous turfgrasses.

Phase 1: Precision Mowing to Encourage Density Over Runners

When grass that spreads is mowed too high, it directs energy into long, leggy stolons that reach outward to find new soil. Mowing at the optimal height forces the plant to tiller (produce new shoots from the base), creating a dense, carpet-like lawn rather than a web of surface runners.

Step-by-Step Mowing Protocol

1. Identify Your Grass Type and Target Height: Hybrid Bermudagrass thrives at 0.5 to 1.5 inches and requires a reel mower for a clean cut. St. Augustine requires 2.5 to 4.0 inches and performs best with a rotary mower. Zoysia sits in the middle at 1.0 to 2.0 inches.
2. Apply the One-Third Rule: Never remove more than 1/3 of the leaf blade in a single pass. Cutting too much shocks the plant, halting lateral spread and triggering weed invasion.
3. Alternate Mowing Patterns: Spreading grasses develop a 'grain' and will lean in the direction they are repeatedly mowed. Alternate your mowing direction (horizontal, vertical, diagonal) every two weeks to keep stolons upright and ensure an even cut.
4. Bag or Mulch Strategically: If your thatch layer is under 0.5 inches, use a mulching blade to return nitrogen to the soil. If thatch is building up, bag the clippings to remove excess organic matter.

Expert Insight: According to the NC State Extension, scalping Bermudagrass in early spring (lowering the deck to 0.5 inches and bagging all debris) removes dead winter material and forces the rhizomes to push new, vigorous green growth upward.

Phase 2: Edging and Physical Containment

The most common failure in maintaining spreading grass is neglecting the perimeter. Stolons can easily cross sidewalks, while rhizomes will tunnel under standard plastic landscape edging.

Installing a Permanent Rhizome Barrier

Standard 4-inch landscape edging is useless against aggressive grasses like Bermudagrass and Torpedo grass. You must install a deep physical barrier.

• Materials Needed: Heavy-duty HDPE plastic barrier (minimum 24 inches deep, such as the DeepRoot 24-inch root barrier), trenching spade, and rubber mallet.
• Step 1: Trenching. Dig a continuous trench along the boundary of the lawn, 6 inches wide and 12 to 18 inches deep (depending on the grass species).
• Step 2: Barrier Placement. Insert the HDPE barrier into the trench. Ensure the top edge protrudes exactly 0.5 inches above the soil grade. This prevents stolons from creeping over the top.
• Step 3: Backfilling and Tamping. Backfill the trench with native soil, tamping it down firmly every 4 inches to eliminate air pockets that rhizomes could exploit.

Maintenance Edging Routine

Even with a barrier, surface stolons will attempt to cross boundaries. Use a gas-powered steel edger (like the McLane 101-4.5GT) every three weeks during peak summer growth to cut a clean 2-inch deep V-trench along concrete and garden beds. Follow up with a string trimmer to clear the debris.

Phase 3: Thatch Management and Core Aeration

Because stoloniferous and rhizomatous grasses produce high amounts of lignin (a tough, woody plant fiber), they are highly susceptible to thatch buildup. A thatch layer exceeding 0.5 inches prevents water infiltration, harbors fungal pathogens, and causes the grass to root into the thatch rather than the soil, making it highly vulnerable to drought.

Step-by-Step Dethatching and Aeration

1. Measure the Thatch: Use a soil probe or a sharp trowel to cut a 3-inch deep wedge into the lawn. Measure the spongy, brown layer between the green grass and the mineral soil. If it exceeds 0.5 inches, dethatching is required.
2. Verticutting (For St. Augustine and Zoysia): Rent a power rake (verticutter) and set the blades to penetrate 1/4 inch into the soil. Run the machine in two perpendicular directions to pull up matted stolons. Rake and remove all debris immediately.
3. Core Aeration (For Bermudagrass and Kentucky Bluegrass): Use a heavy-duty plug aerator to pull 3-inch deep soil cores. Leave the plugs on the lawn to break down naturally; the soil microbes in the plugs will help digest the surface thatch layer.

Phase 4: Fertilization for Controlled Lateral Growth

Over-fertilizing spreading grasses with quick-release nitrogen causes a massive surge in stolon growth, which immediately leads to thatch accumulation and weakens the root system. The goal is steady, controlled growth.

Spreading Grass Maintenance Matrix

Fertilizer Application Steps

• Switch to Slow-Release: Use a methylene urea or sulfur-coated urea fertilizer (such as Milorganite or Scotts Turf Builder SummerGuard). These release nitrogen gradually over 8 to 10 weeks, fueling steady rhizome expansion without triggering thatch-producing growth surges.
• Potassium for Stress Tolerance: Spreading grasses in high-traffic areas need potassium (the third number on the fertilizer bag) to strengthen the cell walls of the stolons. Look for an N-P-K ratio where the K value is at least half of the N value (e.g., 16-4-8).
• Timing: Apply fertilizer only when the grass is actively growing and has been mowed at least twice in the spring. For warm-season spreading grasses, stop all nitrogen applications 6 weeks before your region's first expected fall frost to allow the rhizomes to harden off for winter dormancy.

Phase 5: Watering to Drive Deep Rhizome Growth

Shallow, frequent watering encourages stolons to root at the surface, creating a lawn that is highly susceptible to heat stress and foot traffic damage. To force the grass to spread its rhizomes deep into the soil profile, you must alter your irrigation strategy.

1. Measure Output: Place 3 to 5 straight-sided tuna cans across different irrigation zones. Run the system for 15 minutes and measure the water depth to calculate your sprinkler's hourly output rate.
2. Apply 1 to 1.5 Inches Weekly: Deliver the total weekly water requirement in just two deep watering sessions rather than daily light sprinklings.
3. The 'Footprint Test': Walk across the lawn in the afternoon. If your footprints remain visible and the grass blades do not spring back within 3 minutes, the turf is experiencing moisture stress and requires immediate irrigation. This prevents the grass from wasting energy on lateral stolon production when it should be focusing on survival and deep root growth.

By following these precise maintenance procedures, you harness the self-repairing benefits of grass that spreads while keeping its aggressive nature strictly contained within your designated turf areas. For more detailed regional schedules, consult your local university extension office, such as the Clemson HGIC, to adjust these steps based on your specific microclimate and soil type.