Best String Trimmers to Pair with Your Lawn Mower

Quick Overview

• My top pick for best string trimmers overall is the EGO Power+ ST1521S. It cuts well, lasts long, and shares batteries with EGO mowers and blowers.
• Best for small yards: the WORX 20V, light and easy to swing around tight beds.
• Best for large properties and thick weeds: the Greenworks Pro 80V, the most cutting power in this guide.
• Best budget pick: the Ryobi 40V HP, strong value if you already own Ryobi tools.
• Battery voltage tells you power. Line diameter tells you how tough a trimmer can handle.

A Saturday morning. Coffee in hand. I walk the yard to check my work from the day before, and there it is again: a ragged strip of grass along the fence line, untouched by the mower. My mower is great at open lawn. It is useless at edges, around trees, and along that narrow strip behind the shed.

That gap is why every mower owner eventually needs one of the best string trimmers. A trimmer finishes what a mower starts. It reaches corners a mower deck never will and cleans up edges that make a whole yard look sharp.

I have tested trimmers in three very different climates: muggy Florida summers, dry Arizona heat, and damp Midwest spring mornings. This guide is for any homeowner who owns a mower already and wants the right trimmer to go with it, whether you have a small city lot or two acres of thick grass.

Why a Good Trimmer Matters as Much as Your Mower

A mower and a trimmer do different jobs, and skipping the trimmer leaves your yard half-finished. A mower cuts flat, open ground fast. A trimmer handles the edges, slopes, and tight spots a mower deck can’t reach.

The Jobs Your Mower Can’t Finish

Mower wheels and decks are wide. That width is great for speed but bad for detail work.

Fence lines, tree rings, mailbox posts, and the narrow gap between a sidewalk and a flower bed all need a trimmer. So does any slope too steep for a mower to grip safely.

I learned this the hard way in my own Florida backyard. St. Augustine grass grows fast in humid weather, and within a week the edges around my patio looked shaggy even though the lawn itself was freshly mowed. A five-minute pass with a trimmer fixed it.

Are Battery Trimmers Powerful Enough for Real Edging and Overgrowth?

Yes, for most home yards. Modern 40V to 80V battery trimmers cut through standard grass, light brush, and most weeds without trouble.

The brushless motors used in current models from EGO, Greenworks, and Ryobi run cooler and last longer than the brushed motors from a decade ago. Brushless designs also pull more torque from the same battery, which matters when you hit a thick patch of crabgrass.

Where battery trimmers still struggle is dense, woody brush over a quarter inch thick, or all-day commercial use. For that, a gas trimmer or a high-voltage model like the Greenworks 80V still has an edge. For weekly yard maintenance on a typical residential lot, a quality cordless trimmer keeps up fine.

What to Look for Before You Buy

Six things decide whether a trimmer is worth your money: voltage, runtime, cutting swath, line diameter, shaft style, and the head design. Get those right and the rest is mostly personal preference.

Battery Voltage and Runtime

Voltage is the easiest number to compare, and it roughly tells you how much power the motor has. Entry trimmers run on 20V platforms. Mid-range homeowner trimmers sit at 40V or 56V. High-power models reach 60V to 80V.

More voltage means more torque for thick weeds, but it also means a heavier battery pack. A 20V trimmer is light and fine for small, tidy lawns. A 56V or 80V trimmer handles overgrowth and large properties but adds noticeable weight to your arms.

Runtime depends on both voltage and amp-hours (Ah), which is the battery’s storage capacity. A small 2.0Ah pack on a 56V trimmer might run 35 to 45 minutes. A larger 4.0Ah pack on the same trimmer can stretch past an hour. If your yard takes more than 30 minutes to trim, buy a second battery or a bigger pack up front.

Cutting Swath and Line Diameter

Cutting swath is the width of the path the trimmer head clears in one pass. Most homeowner trimmers run 12 to 16 inches. A wider swath means fewer passes and a faster job, but a slightly heavier head.

Line diameter matters more than people expect. Thin 0.065-inch line is fine for light grass and tidy edging, but it snaps fast against weeds, mulch, or rocks. Standard 0.080-inch line handles typical residential mowing plus occasional weeds. Thick 0.095-inch line chews through dense weeds and neglected patches without breaking every five minutes.

You cannot just load thicker line into a trimmer built for thin line. The motor and gearbox need to be rated for it, or you risk burning out the motor.

Straight Shaft vs. Curved Shaft

A straight shaft trimmer is longer and lets you reach further under bushes, fences, and low shrubs. It is the better choice if you have any tree rings or raised beds to trim around.

A curved shaft trimmer is shorter and a bit lighter to swing, which makes it more comfortable for short people or smaller yards with simple, open edges. It is less common on higher-power models, since most brands build their 40V-and-up lineups with straight shafts.

Trimmer Heads — Bump Feed vs. Fixed Line vs. Easy-Load

Bump feed is the most common head style. You tap the head on the ground while it spins, and it releases more line automatically. It is reliable and works on almost every brand, though reloading the spool takes a minute or two.

Fixed-line heads hold a single pre-cut piece of line. They are simple and cheap to maintain but need manual replacement once the line wears down, which happens faster on rough terrain.

Easy-load or auto-feed systems, like EGO’s Line IQ or PowerLoad, let you snap in pre-measured line without unwinding a spool by hand. These cost more but save real time if you trim often.

Comparison Table: Trimmer Specs at a Glance

The Best String Trimmers I’ve Tested

I focused this list on trimmers homeowners can realistically buy and pair with the mower they already own, not commercial-only equipment. Specs below reflect current 2026 listings from each brand (EGO, Greenworks, 2026; Power Tool Insider, 2026).

Best Overall: EGO Power+ ST1521S (56V)

The EGO ST1521S earns the top spot because it balances power, runtime, and comfort better than anything else I tested. It is a 56V trimmer with a 16-inch cutting swath and a bump-feed head loaded with 0.095-inch line.

Out of the box, it felt noticeably lighter in my hands than the Greenworks 80V, even though both clear thick grass without bogging down. EGO’s ARC Lithium battery platform also powers EGO mowers and blowers, so if you already run an EGO mower, this trimmer shares the same charger and packs.

My one real complaint: EGO’s pre-cut line cartridges aren’t cheap, and using off-brand line in the auto-feed versions can jam the head. Stick with EGO-approved line and you won’t have the problem.

Best for: Homeowners already on the EGO 56V platform, or anyone who wants gas-level cutting power without the noise or fumes.

Best for Small Yards: WORX 20V

For a small lot or a townhome with simple, square edges, the WORX 20V is hard to beat. It weighs under 5 pounds and includes a built-in 90-degree edging conversion, so the same tool trims grass and edges a sidewalk.

I tested this one on a quarter-acre suburban lot in Ohio, and it handled the lawn in under 15 minutes without any arm fatigue. It will not power through thick weeds or tall overgrowth, so don’t expect it to replace a heavier trimmer on a neglected yard.

Best for: Small, well-maintained lots where light weight and easy edging matter more than raw power.

Best for Large Properties and Thick Weeds: Greenworks Pro 80V

The Greenworks Pro 80V delivers the most cutting power in this guide. At 80 volts, it has more headroom than the 56V EGO or 40V Ryobi, and the 16-inch swath clears ground fast.

I ran this one through a patch of waist-high weeds at the edge of a Minnesota property that hadn’t been touched all spring. It plowed through without stalling, something the lighter 40V models in this test could not match. The trade-off is weight. After 30 minutes, my shoulder noticed it, and a strap is close to mandatory here.

Best for: Larger lots, thick weeds, and neglected areas that need real torque.

Best Budget Pick: Ryobi 40V HP

The Ryobi 40V HP gives you brushless performance and the Expand-It attachment system, which lets the same motor head run an edger, pole saw, or hedge trimmer attachment, at a price well under EGO or Greenworks.

It is not as refined as the EGO. The line feed is a bit less consistent, and runtime on the included battery is shorter than the premium options. But for the price, and especially if you already own other Ryobi 40V tools, it’s the smartest value buy here.

Best for: Ryobi tool owners, or anyone who wants attachment flexibility without paying premium prices.

Best for Edging Precision: SKIL PWR CORE 40V

SKIL surprised me. At 6.8 pounds, the PWR CORE 40V is one of the lightest brushless trimmers I tested, and the battery includes temperature management that protects the pack from heat damage during long sessions (Power Tool Insider, 2026).

Edging along my driveway, the lighter head gave me more control than the heavier Greenworks, letting me follow a straight line without fighting the tool’s weight. It does not have the runtime to handle a large property in one charge.

Best for: Detail edging work and homeowners not already locked into another battery platform.

Comparison Table: My Top Trimmer Picks

How Trimmer Performance Holds Up in Real Conditions

A trimmer that performs well in a lab spec sheet does not always perform well in your actual backyard. Climate and terrain change how a trimmer feels and how long the battery lasts.

Hot and Humid Climates (Florida, Texas, Southeast)

Humidity thickens grass blades and makes them tougher to cut cleanly, so a trimmer with thinner line tends to leave a ragged, torn edge instead of a clean cut. I noticed this clearly with St. Augustine and Zoysia grass during a Florida summer.

Heat also affects battery performance. Lithium packs lose some efficiency above 90 degrees Fahrenheit, and I saw runtime drop by roughly 10 to 15 percent on the hottest afternoons compared to a cooler morning session. Trimmers with battery temperature monitoring, like the SKIL PWR CORE, held up better across a hot day.

Dry and Rocky Terrain (Southwest, Arizona)

In Phoenix, dry desert landscaping means less actual grass and more rock borders, gravel beds, and tough desert weeds. Line wears out faster here because it constantly bumps against rocks and concrete edging.

Bump-feed heads earned their keep in this environment. I went through more line overall, but reloading took seconds, and that mattered more than runtime in rocky terrain. A thicker 0.095-inch line also lasted noticeably longer than 0.065-inch line on the same gravel border.

Thick Weeds and Midwest Overgrowth

Spring in Minnesota and similar climates brings fast, dense weed growth after snowmelt, especially if a yard sat untouched over winter. This is where voltage and torque mattered the most in my testing.

The 40V and 56V trimmers cut standard grass fine but slowed down in patches of thick dandelion stems and crabgrass clusters. The 80V Greenworks kept a steady cutting speed through the same patches without bogging down.

Comparison Table: Climate Performance Notes

Common Mistakes People Make When Buying

Most trimmer regrets come down to two things: picking the wrong power level, or ignoring how much the replacement line will cost over time.

Buying the Wrong Voltage for Your Yard Size

A common mistake is buying the highest voltage trimmer available, assuming more power is always better. For a small, tidy quarter-acre lot, an 80V trimmer is overkill. It costs more, weighs more, and you’ll fight the extra bulk for a job that a 20V or 40V trimmer handles easily.

The opposite mistake also happens. Buying a light 20V trimmer for a large property with thick weeds leads to a motor that bogs down constantly and a battery that dies halfway through the yard. Match voltage to your actual yard size and vegetation, not to the biggest number on the shelf.

Ignoring Line Diameter and Replacement Cost

Buyers often look at the trimmer price and ignore the ongoing cost of replacement line. Thicker line and proprietary cartridges, like some of EGO’s auto-feed line, cost more per refill than a basic spool of 0.080-inch line from a hardware store.

If you trim weekly through a long growing season, that cost adds up. Check whether your trimmer accepts standard universal spools before you buy, especially if budget matters to you long term.

My Final Recommendation

After running all five of these trimmers through three different climates, the EGO ST1521S is still the one I’d buy again. It has enough power for real overgrowth, enough runtime for a normal yard, and it pairs cleanly with EGO mowers if you’re already building that battery ecosystem.

If your yard is small and tidy, don’t overspend on power you won’t use. The WORX 20V will save your arms and your money. And if you’re dealing with a genuinely overgrown property, the Greenworks Pro 80V is worth the extra weight on your shoulder.

Whichever one you choose, match it to the yard you actually have, not the yard you wish you had. That one decision matters more than any single spec on the box.

Pros and Cons Table

Frequently Asked Questions About String Trimmers

What is the best string trimmer for a homeowner with a small yard?

The WORX 20V is the best fit for small, well-maintained lots. It’s light, includes an edging conversion, and finishes a quarter-acre lawn quickly without arm fatigue.

How does battery voltage affect trimmer performance?

Higher voltage means more torque and power for cutting through thick weeds and brush. Lower voltage trimmers are lighter and fine for light grass, but they bog down faster in dense vegetation.

What is the difference between a straight shaft and curved shaft trimmer?

A straight shaft trimmer is longer and reaches further under bushes and fences, which makes it better for tree rings and raised beds. A curved shaft trimmer is shorter and lighter, which suits simple, open edges on smaller yards.

Are cordless string trimmers powerful enough to replace a gas trimmer?

For most residential yards, yes. Modern 40V to 80V brushless trimmers match gas-level cutting power for standard grass and weeds. Gas trimmers still have an edge for all-day commercial use or very dense brush.

How thick should my trimmer line be?

Use 0.065-inch line for light grass and edging only. Use 0.080-inch line for typical weekly residential mowing. Use 0.095-inch line if you regularly deal with thick weeds or a neglected, overgrown yard.

How long does a string trimmer battery last per charge?

Runtime depends on voltage and amp-hours. A 2.0Ah to 2.5Ah battery on a mid-power trimmer typically runs 35 to 60 minutes. A larger 4.0Ah pack can stretch well past an hour, depending on how thick the vegetation is.