Keeping your garden tidy and beautiful is not an easy thing. Except for using a lawn mower, you also need to use the string trimmer to create a sharp line between your grass and the driveway or flower bed. This guide will teach you how to edge with a string trimmer in just a few minutes, and we’ll cover the common mistakes to avoid along the way.
What Is a String Trimmer?
A string trimmer is one kind of multi-use garden tool, it uses fast fast-turning nylon rope to cut grass and wild weeds. It is very suitable for cleaning those places a lawn mower cannot go, like beside trees, fence poles, and wall edges. Knowing what it is can help you understand how to edge with a string trimmer.
How to Use a String Trimmer
Before we learn to edge, it’s important to know the difference. Trimming is the primary function of the tool. It involves holding the trimmer so the string is parallel to the ground, swinging it side-to-side like a scythe to cut down tall grass and weeds. Edging, which we will cover below, is a different technique where you turn the tool vertically to create a sharp border.
Pre-Work You Need to Prepare
A great result starts with a little preparation. Don’t skip these steps!
1. Gather Your Gear
Safety is not optional. Before you even start, make sure you have:
- Safety glasses (essential to protect from flying debris)
- Sturdy, closed-toe shoes
- Long pants
- Work gloves (optional, but recommended for better grip)
2. Prepare the Area
- Clear the Path: Walk the entire area you plan to edge. Remove any rocks, toys, garden hoses, or large branches. This prevents the string from catching and flinging dangerous projectiles.
- Mow the Lawn First: Always mow your lawn before you edge. Mowing sets the final height for the majority of your grass. Edging afterward allows you to create a clean line that perfectly matches the rest of your lawn, giving it a seamless, manicured appearance.
3. Plan Your Path
For straight edges along sidewalks or driveways, the concrete itself is your guide. For curved edges around flower beds, lay down a garden hose to create a smooth, visual line to follow. This is a pro tip for achieving graceful curves.
4. Prepare the Trimmer
- Check Fuel/Battery: For gas models, ensure the tank is full. For electric models, make sure the battery is fully charged.
- Inspect the Trimmer Line: Look at the line. Is it frayed, brittle, or too short? A worn-out line will break easily and won’t cut cleanly. Replace it if necessary.
5 Steps to Edge with a String Trimmer
1. Flip It and Get Set
- Hold the trimmer vertically (90°), so the line spins like a wheel.
- Grip from the side of the handle so your thumb rests naturally on the trigger.
- Stand with feet shoulder‑width apart, knees slightly bent for balance.

2. Mark Your Edge
- Use the line where grass meets a hard surface (sidewalk, driveway, flowerbed).
- If needed, lay down a garden hose as a visual guide.
- Cut along the edge—not on top of hard surfaces.
3. Make the First Cut
- Start the trimmer and let it reach full speed.
- Lower gently so only the tip of the string touches the grass.
- Listen for the sharper cutting sound—don’t push or force it.
- Keep the string straight up and down (90°) for a clean trench.
4. Walk the Line
- Move smoothly and slowly, like painting a steady stroke.
- Walk against the spin: Clockwise spin → walk left to right; Counterclockwise spin → walk right to left.
- Take small bites instead of rushing—this gives a straighter edge.
5. Reveal the Edge
- Blow off debris with a leaf blower or sweep with a stiff broom.
- Clear clippings off sidewalks/driveways, back onto the lawn.
- Watch your edge pop out—sharp, neat, and professional.
Common Mistakes to Avoid
1. Holding the trimmer at the wrong angle
- Mistake: If you don’t keep the trimmer straight up and down (90°), your edges will look crooked, or you might scalp the grass.
- Fix: Before switching it on, practice holding the tool vertically and walking a few steps. This helps you get used to the motion.
2. Letting the trimming line get too short
- Mistake: A short line won’t cut well and can put extra stress on the motor.
- Fix: Use the bump feed (or your trimmer’s line release system) to feed out more line whenever needed. Keep the line at its proper cutting length for the best results.
3. Using a line that’s too long
- Mistake: If the line is too long, the trimmer loses cutting power, your edges get messy, and the whipping line could even hit you.
- Fix: The guard on your trimmer has a small blade that trims the line to the right length. If it’s still too long, turn off the tool and carefully cut the line shorter yourself.
What If I Don’t Have One?
You can still keep your lawn edges neat with other tools:
- Manual Edger: A half-moon blade on a handle. Step on it with your foot to slice a clean line. Quiet, effective, and gives you some exercise, too.
- Flat Spade: In a pinch, a regular garden spade works for cutting simple edges.
- Power Edger: A machine with a steel blade and a guide wheel. It makes the sharpest, most professional edges, but costs extra.
4 Safety Tips You Shouldn’t Ignore
- Watch for Flying Debris: Always wear safety glasses, and keep kids and pets away while trimming.
- Keep the Guard Attached: It protects you from debris and keeps the line at the right length. Never remove it just to see better.
- Check the Area First: Locate sprinkler heads, buried wires, and lights to avoid damaging them.
- Mind the Exhaust: Don’t start or run a gas-powered trimmer in a closed area like a garage—carbon monoxide is dangerous.
FAQs
What is the difference between a string trimmer and an edger?
A string trimmer uses a flexible line to cut grass, making it versatile for both trimming and edging. A dedicated edger uses a rigid metal blade specifically to create sharp, precise lines along hard surfaces.
How often should you edge your lawn?
As a general rule, edging once a month during the growing season is sufficient. However, if you have fast-growing grass types, you may need to edge as often as every two weeks to maintain a sharp look.
Can I use a string trimmer on all types of grass?
Yes, but you may need to adjust your technique for different grass types. For delicate grasses, avoid digging too deep. For tough, dense grasses, you may need a more powerful trimmer or thicker line.
Conclusion
After learning how to edge with a string trimmer, edging your lawn with a string trimmer is a simple skill as long as you follow the right method. And it’s an easy and cost-effective way to make your house look attractive. And I believe after a few tries, you can finish it better every time.
Need Parts for Your Trimmer?
Although as time goes by, your string trimmer may wear and tear, there is nothing to worry about. FridayParts is always there as your backup. We offer a range of high-quality trimmer parts to maintain your tools. Without brand premium, but with global shipping and fast delivery, order today and find other power tools components at our one-stop online shop!
