7 Best Gas Lawn Mowers for Thick Grass (2025 Guide)

The YARDMAX Select PACE roars through thick turf with a muscular 201cc engine and a 6-speed CVT that matches your stride without hunting for gears. Its Maxflow volute spiral deck boosts airflow for cleaner mulching, while the heavy-duty 16‑gauge steel deck shrugs off bumps. Add 11-inch rear wheels with spike-tread rubber tires and you get standout traction that keeps power to the ground on uneven lawns.

In testing on fescue and overgrown patches, the YARDMAX maintained blade speed through dense growth and damp morning cuts. The 22-inch deck covers ground quickly, and a single-lever height adjuster offers seven settings from 1.38 to 3.55 inches for scalp-free passes. The deck cleanout port simplifies washdowns, though the larger deck can feel bulky around tight landscaping.

Compared with the PowerSmart B&S rear-drive models, the YARDMAX’s CVT pacing and larger engine deliver stronger grunt and smoother control on mixed terrain. It’s ideal for homeowners with medium-to-large yards, varied slopes, and thick grasses who value traction and cut quality. If you want a lighter machine, the AMERISUN 170cc trades some finesse for raw power, but the YARDMAX offers a richer feature set for performance-minded users.

The PowerSmart 21-inch with a 140cc Briggs & Stratton engine is a nimble climber that punches above its weight on dense turf. Rear-wheel drive and 10-inch rear wheels give it surefooted grip, making it a confident pick for hilly yards. Its 3‑in‑1 system and single-lever height control make setup quick when switching from mulching to bagging between growth spurts.

On thick St. Augustine and damp rye, this mower maintained steady pace without frequent stalling, especially in self-propelled mode. The 21-inch steel deck and 1.5–3.9 inch range handled seasonal transitions well; bag capacity is modest but practical for weekly cuts. In very tall grass, you’ll get best results with a two-pass approach to keep airflow strong.

Versus the YARDMAX 201cc, this PowerSmart is more agile and lighter on slopes but offers less raw torque in heavy, wet growth. It’s a smart fit for medium yards with rolling terrain where traction and control matter more than brute force. Compared to the AMERISUN 170cc, you trade peak power for a smoother hill-climbing experience and user-friendly handling.

AMERISUN’s self-propelled mower brings 170cc OHV power with forced air cooling, a combo that keeps blade tip speed high when chewing through thick or uneven grass. The 21-inch steel deck balances coverage and control, while the 1.4‑bushel bag and 3‑in‑1 cutting modes offer flexible yard cleanup. Large rear wheels and a simple foldable handle enhance maneuverability and storage.

In real-world use, it powered through overgrown patches and damp morning dew with fewer slow-downs than many mid-size engines. The 1.5–3.9 inch height range provides scalp protection on bumpy areas, and self-propel helps manage longer sessions. It’s slightly heavier than push models, so it’s happiest in straight-line mowing or broad curves.

Compared to the PowerSmart B&S lineup, AMERISUN delivers more torque for dense growth but feels less feathery on hills. Against the YARDMAX 201cc, it’s a value-savvy middle ground—stronger than 140cc units but simpler than CVT-driven systems. For thick grass in medium-to-large yards, it’s a compelling power-first pick that undercuts premium feature sets while preserving performance.

This PowerSmart self-propelled model couples a 140cc B&S engine with rear-wheel drive and 10-inch wheels, giving it assertive traction that matters when grass gets thick and slick. The 21-inch steel deck and 3‑in‑1 setup let you pivot from mulching to bagging depending on growth. A single-lever, 6-position height adjuster keeps adjustments fast when tackling transitions.

Across dense patches and damp edges, it resisted bogging better than many entry-level units, provided you maintain blade sharpness. The 1.5–3.9 inch range helps prevent clumping in heavy growth by stepping down height in stages. It’s not the lightest, but propulsion keeps fatigue in check during longer mow sessions.

Compared with the PowerSmart slope-focused sibling, this one emphasizes traction and consistency in thick grass, trading a bit of agility for stability. It’s best for medium yards with mixed terrain where grip and steady blade speed matter. Against the YARDMAX 201cc, you forgo CVT finesse and extra power but get a solid, no-drama performer for challenging weekly cuts.

The SENIX LSPG-M4 is a budget-friendly push mower with a 125cc Briggs & Stratton engine that favors simplicity and low maintenance. Its 21-inch steel deck and 2‑in‑1 mulching/side discharge keep the essentials without extra complexity. 11-inch rear wheels help it roll over uneven patches better than typical entry-level push mowers.

In thick grass, it performs best with staged cuts—start high, then drop height for a cleaner finish and reduced clumping. The 1.25–3.75 inch height range offers a slightly lower minimum, useful for manicured looks on warm-season lawns. As a push mower, it requires more effort in dense or wet turf, so plan for slower, methodical passes.

Compared to the PowerSmart push model, the SENIX is simpler and quieter but lacks bagging and high-output torque for heavy growth. It’s ideal for small to medium flat yards where cost, reliability, and easy storage matter more than speed. When stacked against the AMERISUN 170cc, the SENIX trades power for affordability and straightforward operation.

PowerSmart’s 144cc push mower is a value-forward option that still checks the thick-grass boxes with a 21-inch steel deck and 3‑in‑1 versatility. The auto choke streamlines starts, and the dual‑lever, 6-position height adjustment covers 1.5–3.9 inches for seasonal tweaks. Its foldable design is a bonus for tight storage spaces.

In dense turf, it benefits from two-pass mowing and keeping the blade sharp; bagging helps prevent clumps during rapid growth. The wider deck reduces time on open runs, though manual push effort rises in wet conditions. It’s a practical pick for homeowners who need bagging and mulching without stepping up to self-propel.

Versus the SENIX, this model adds bagging capability and a bit more engine muscle, making it more adaptable during peak growth weeks. Compared to self-propelled options like the PowerSmart RWD, you trade ease on hills for a lighter, simpler chassis. For flat to mildly uneven yards, it offers strong utility without complexity.

This AMERISUN push mower leans into rough-terrain control with oversized 10-inch rear wheels, wide 1.5-inch treads, and dual ball bearings for smoother tracking. The 144cc OHV engine with auto choke keeps starts reliable and maintenance simple. A 21-inch reinforced steel deck and 3‑in‑1 cutting suite with a 1.4‑bushel bag round out a highly usable package.

On uneven ground and thick patches, the wheel setup preserves momentum and keeps the deck stable, minimizing scalps. The single-lever, 6-setting height system from 1.5 to 3.9 inches lets you step up for heavy growth, then drop for finish passes. As a push unit, expect more effort on long runs, especially in wet, tall grass.

Compared with the PowerSmart push, AMERISUN’s traction-focused wheels provide better control over ruts and roots, while performance remains similar in light-to-moderate growth. Against self-propelled options like the YARDMAX, you give up powered drive but keep agility and terrain confidence. For bumpy yards where maneuverability matters, it’s a standout, feature-rich push choice.