Caring for a St. Augustine lawn requires a mower that can handle its thick, dense growth pattern without tearing or damaging the turf. The right machine provides a clean, even cut that promotes a healthy, lush carpet of grass, all while making your weekly chore more efficient and less of a burden.
Gas mowers offer the power and runtime needed to tackle larger yards without being tethered to a cord. This roundup focuses on models with the specific features—like robust engines, versatile cutting options, and durable decks—that are perfectly suited for maintaining the vibrant beauty of your St. Augustine grass throughout the season.
The Best Gas Mowers for a Perfect St. Augustine Lawn
- PowerSmart 21-Inch Gas Lawn Mower with B&S Engine
- PowerSmart Gas Lawn Mower 21″ with OHV 144cc Engine
- PowerSmart 21-Inch Self-Propelled Mower with B&S 140cc Engine
- AMERISUN Self-Propelled Gas Lawn Mower, 170cc OHV Engine
- AMERISUN 21″ Gas Lawn Mower, 3-in-1 Gas Push Mowers
- PowerSmart 21″ 3-in-1 Gas Push Lawn Mower
- Honda HRN216VKA 21-Inch 3-in-1 Variable Speed Gas Mower
- Toro Recycler 22-Inch SmartStow Gas Walk-Behind Mower
PowerSmart 21-Inch Gas Lawn Mower with B&S Engine
This PowerSmart model is built for reliability, featuring a 140cc Briggs & Stratton engine known for its consistent performance and long-term durability. It’s an excellent choice for handling the tough, thick blades of St. Augustine grass without stalling. The self-propelled, rear-wheel drive system provides excellent traction and reduces user effort, especially on slight inclines.
The 21-inch steel deck offers a wide cutting path to cover more ground quickly. With six cutting height positions, you can easily find the ideal setting for St. Augustine, which thrives with a slightly taller cut. The 3-in-1 functionality gives you the flexibility to bag clippings for a clean look, mulch to return nutrients to the soil, or use rear discharge for efficient mowing in taller grass.
PowerSmart Gas Lawn Mower 21″ with OHV 144cc Engine
If you’re looking for a lightweight and easy-to-maneuver option, this PowerSmart push mower is a strong contender. Its 144cc OHV engine provides ample power for standard mowing tasks, while the 62-pound design makes it simple to navigate around garden beds and tight corners. This can be particularly useful for yards with many obstacles.
The 2-in-1 mulching and side discharge system allows you to choose between nourishing your lawn with fine clippings or quickly clearing away grass. With six height adjustments, you can maintain the recommended cutting height for St. Augustine grass. This mower is a straightforward, efficient tool for smaller to medium-sized lawns where a self-propelled feature isn’t a necessity.
PowerSmart 21-Inch Self-Propelled Mower with B&S 140cc Engine
This self-propelled PowerSmart mower combines a trusted 140cc Briggs & Stratton engine with the convenience of not having to push. The dependable engine is designed for smooth startups and consistent power, which is ideal for mowing through thick St. Augustine grass, even when it’s slightly damp. The rear-wheel drive offers good control and stability.
The 21-inch durable steel deck ensures a clean and even cut across your lawn. You have full control over grass clippings with the 3-in-1 system, allowing for bagging, mulching, or rear discharge. The larger 10-inch rear wheels help this mower roll smoothly over uneven terrain, providing a more consistent cut across your entire yard.
AMERISUN Self-Propelled Gas Lawn Mower, 170cc OHV Engine
For those with particularly challenging lawns, the AMERISUN mower brings extra power to the table. Its 170cc OHV engine is one of the most powerful in this roundup, easily tackling thick, overgrown St. Augustine grass. The forced air-cooling system is a key feature, helping to maintain engine performance and longevity during extended mowing sessions under heavy load.
The 21-inch steel deck is built for speed and durability, covering a wide path with each pass. The 3-in-1 function, paired with a spacious 1.4-bushel grass catcher, gives you multiple options for dealing with clippings. This self-propelled model is a workhorse designed for larger properties where power and endurance are top priorities.
AMERISUN 21″ Gas Lawn Mower, 3-in-1 Gas Push Mowers
This AMERISUN push mower offers a great balance of power and user-friendly features. The 144cc 4-cycle engine with auto-choke makes starting simple and reliable. Its sturdy 21-inch steel deck is designed to provide a consistent cut across your lawn, making it a solid choice for standard residential mowing needs.
A standout feature is its wheel design. The combination of 7-inch front wheels and oversized 10-inch rear wheels with wide treads provides superior traction and makes it easier to push over uneven ground. This enhanced maneuverability is a significant benefit for lawns that aren’t perfectly flat, helping to ensure an even cut for your St. Augustine grass.
PowerSmart 21″ 3-in-1 Gas Push Lawn Mower
This model is another reliable push mower from PowerSmart, centered around a dependable 140cc Briggs & Stratton engine. The forced air-cooling system helps maintain optimal engine temperature, contributing to its durability and consistent performance when mowing in warm weather. It’s a straightforward machine built for effective weekly maintenance.
You get full versatility with the 3-in-1 cutting system, allowing you to mulch, bag, or side-discharge clippings based on your lawn’s condition and your personal preference. The six cutting height positions, adjustable from 1.5 to 3.9 inches, are controlled by dual levers for quick and easy changes to achieve the perfect height for St. Augustine grass.
Honda HRN216VKA 21-Inch 3-in-1 Variable Speed Gas Mower
Honda mowers are renowned for their exceptional reliability and superior cutting performance. The HRN216VKA features a dependable Honda engine known for easy starts and smooth operation. The variable speed self-propelled drive lets you perfectly match your walking pace to the thickness of the grass, giving you complete control in any condition.
Its 3-in-1 system offers bagging, mulching, and discharging capabilities. Honda’s MicroCut twin-blade system is a significant advantage, chopping grass clippings into finer pieces. This results in a cleaner-looking lawn when bagging and creates a more effective, faster-decomposing mulch that can better nourish your St. Augustine grass without clumping.
Toro Recycler 22-Inch SmartStow Gas Walk-Behind Mower
The Toro Recycler is a premium option famous for its innovative Personal Pace self-propelled system. This intuitive system automatically adjusts the mower’s speed to your walking pace, making it incredibly easy to use on any terrain. The 22-inch deck is slightly wider than standard, which can reduce mowing time for larger lawns.
A key feature is the advanced mulching capability, which uses a unique blade and deck design to recut clippings multiple times. This creates a fine, nutrient-rich mulch that virtually disappears into the lawn, feeding the St. Augustine grass without leaving any debris behind. The SmartStow design allows the mower to be stored vertically, saving significant storage space.
Buying Guide: What to Look For in a Gas Mower for St Augustine Grass
Taking care of St. Augustine grass is a bit different from other lawn types. It’s a thick, broad-leafed turf that can be prone to disease if cut incorrectly, so your mower choice really matters. I’ve found that a few key features separate a good cut from a great one for this specific grass.
First and foremost, let’s talk about cutting height. St. Augustine needs to be cut higher than most grasses—typically between 3.5 to 4 inches. Cutting it too short, a practice called “scalping,” exposes the stems to the sun, stresses the plant, and invites weeds and disease. Because of this, you need a mower with a wide range of height adjustments that can comfortably reach these higher settings. Don’t even consider a mower that maxes out at 3 inches; it just won’t do the job properly.
Next up is deck construction and design. A stamped steel deck is common on many residential mowers and works just fine, but if you can swing it, a fabricated steel deck is more durable and often provides a better vacuum seal. This leads to a superior lift, standing the grass blades upright for a cleaner, more even cut. The shape of the deck also plays a role; some are designed to reduce clogging, which is a real bonus when dealing with the sometimes-damp, thick clippings of St. Augustine.
Engine power is another big one. You don’t necessarily need the biggest engine on the market, but you do need enough torque to power through thick patches without stalling. I look for a engine in the 160cc to 190cc range for a push mower, and more for a self-propelled model. A mower that bogs down mid-cut will tear the grass instead of slicing it cleanly, leaving frayed, brown tips.
Finally, consider the mower type. A standard push mower is great for smaller, flat lawns. If your yard has any kind of slope or is simply large, a self-propelled model is a back-saver. The drive system—whether front-wheel, rear-wheel, or all-wheel drive—affects traction and maneuverability. For hilly terrain, rear-wheel drive usually offers the best grip.
When I’m evaluating the 8 best gas lawn mowers for St Augustine grass care, these are the non-negotiable features I check for. Getting the right combination of height, power, and deck design ensures your lawn stays healthy, thick, and beautiful all season long.
Frequently Asked Questions
What is the best height to cut St. Augustine grass?
I always recommend keeping St. Augustine grass between 3.5 and 4 inches tall during the main growing season. This taller height shades the soil, which helps prevent weeds and conserves moisture. It also promotes a deep, strong root system. You can drop the height to around 2.5 inches for the final cut of the season, but never scalp it down shorter than that, as it severely stresses the turf.
Is it better to bag or mulch St. Augustine grass clippings?
For St. Augustine, I’m a big fan of mulching. Using a mulching mower with a dedicated mulching blade chops the clippings into tiny pieces that decompose quickly and return valuable nutrients to the soil. This acts as a natural fertilizer. You should only bag if the grass is excessively long or wet, as thick mats of clippings can smother the turf. Otherwise, let those clippings feed your lawn.
How often should I mow my St. Augustine lawn?
This depends entirely on how fast it’s growing, which is influenced by rain and fertilizer. A good rule of thumb I follow is to never remove more than one-third of the grass blade in a single mowing. So, if your ideal height is 4 inches, you should mow when the grass reaches about 6 inches. During peak growth in spring and early summer, this might mean mowing every 5-7 days.
Can a dull mower blade harm my St. Augustine grass?
Absolutely. A dull blade is one of the worst things for any grass, especially St. Augustine. Instead of making a clean cut, it tears and shreds the grass blades. These ragged tips turn brown, making your whole lawn look dull and unhealthy. More importantly, torn grass is more susceptible to disease. I sharpen my mower blades at least twice a season to ensure a clean, healthy cut.
What type of mower is easiest to use on a hilly yard with St. Augustine?
If you have hills, a self-propelled gas mower is the way to go. Specifically, look for a model with a rear-wheel drive system. Rear-wheel drive provides better traction and power when going uphill, making it much easier and safer to handle than a push mower or even a front-wheel drive model. This is a key feature I consider when looking at the 8 best gas lawn mowers for St Augustine grass care on uneven terrain.