Edger vs String Trimmer | Which Tool For Your Yard?

A string trimmer is the better primary buy for most homeowners because it handles trimming and edge maintenance, while a dedicated edger is only needed for carving sharp, deep borders along hardscapes.

Every spring, the same question surfaces in the garage: do you need both tools, or can one do the job? The answer depends on how you want your lawn edges to look and how much work you’re willing to do to get them there. The string trimmer (weed wacker) uses a spinning nylon line to cut grass in tight spots, while an edger uses a vertical metal blade to slice clean borders. One is a multi-purpose tool, the other is a specialist. Here’s how to decide which belongs in your shed.

How They Cut: Nylon Line vs Metal Blade

The core difference is the cutting method. A string trimmer spins a flexible nylon line at high speed to slice through grass and weeds around fences, trees, and under decks. An edger spins a rigid metal blade vertically to cut a trench along sidewalks and driveways, creating that crisp line between lawn and pavement.

Because the trimmer line is flexible, it bounces off hard surfaces rather than digging into them. The edger’s blade, however, cuts into soil aggressively — up to 4.5 inches deep on most models. That depth is what gives you the sharp, defined border professionals aim for.

Versatility: One Tool That Does It All

The string trimmer wins on versatility by a wide margin. With the trimmer head rotated 90 degrees, the line spins vertically, allowing you to maintain existing edges along sidewalks and driveways. Many string trimmers also accept attachment systems — pole saws, brush cutters, and even dedicated edger attachments that turn the trimmer into a hybrid tool.

An edger does one thing: edge. It cannot trim under a fence or cut weeds growing through a flower bed. If you own only an edger, you will still need a trimmer for everything else. The reverse is not true: a string trimmer, used correctly, can handle both jobs for most lawns.

Which Lawn Edge Are You After?

This is where the choice gets personal. A string trimmer creates a rounded, maintained edge — it cleans up overgrowth but does not cut a new line into the soil. If your lawn already has defined borders and you just want to keep them clean, the trimmer is enough.

If you are starting from scratch, or you want that 90-degree trench that makes a lawn look manicured, you need an edger. Manual edgers are the tool for carving new edges around flower beds and garden borders. Wheeled edgers handle longer runs along driveways with less effort.

Edger vs String Trimmer: Side-by-Side Comparison

Which Tool Should You Buy?

For most homeowners, a string trimmer is the smarter investment. It costs between $95 and $350 and covers more use cases than any edger. An entry-level cordless model from BLACK+DECKER runs about $119 and handles trimming and edge maintenance on a typical suburban lot. If your yard has straight driveways, long sidewalk runs, or formal flower beds, and you want a professional-looking border, add an edger to your lineup. Stick edgers start around $30 and work fine for small jobs; wheeled models run $100 to $300 and handle larger projects without bending over.

Professionals and perfectionists will want both. A trimmer for the fence lines and a dedicated edger for the sharp borders. Many readers looking for a solid all-in-one option will find our roundup of the top cordless trimmer edger combos helpful for finding a model that does both jobs well.

Two common mistakes trip people up. First, expecting a cordless trimmer to edge as well as a gas or plug-in model — cordless units have less power, so they struggle with deeper cuts. Second, assuming a string trimmer can carve a new edge into soil. It cannot. For new borders, always use a manual or stand-alone edger.

How To Edge With A String Trimmer

If you already own a trimmer and want to maintain your existing edges, the technique is simple. Rotate the trimmer head 90 degrees so the string spins vertically. Hold the trimmer so the line contacts the grass at the edge of the sidewalk, not the pavement itself. Move slowly along the border. This maintains the line but will not deepen it. For a deeper cut, switch to an edger or a trimmer with an edger attachment.

Ditch the Electric? When Gas Powers Through

Gas trimmers handle heavier work and thicker weeds better than cordless electric models. Two-cycle models (like the Troy-Bilt TB25CB) require mixing oil and gas in a separate container before every fill-up. Four-cycle models (like the Troy-Bilt TB252S) run on gasoline alone, with oil in a separate reservoir. Both deliver more sustained power than battery units, though cordless technology has closed the gap significantly in the last few years.

For edging specifically, gas and corded electric edgers cut more aggressively than cordless models because they do not lose power as the battery drains. If you edge a long driveway, a gas or corded model avoids the mid-job recharge.

Final Decision: One Tool or Two?

Ask yourself one question: how sharp do you want your lawn edges? If the answer is “sharp enough that a neighbor comments,” buy both — a string trimmer for general work and an edger for the borders. If the answer is “just keep the grass off the sidewalk,” a string trimmer alone will do the job.