I keep damaging the bottom of my fence with my gas weed trimmer. What is the best way to prevent damage to my fence while using a gas trimmer?

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  • Welcome to the site. Your question is certainly on-topic here. I'm not sure what you mean by adding the lawn tag -- you already have it. And if you have a suggestion for the faq, please start a discussion on Gardening & Landscaping Meta.
    – Niall C.
    Commented May 22, 2013 at 3:41
  • Might just be easier in the long run to cut 3 inches off the bottom of each board so you can weedeat under it. It'd look cleaner that way, too.
    – cutrightjm
    Commented May 22, 2013 at 3:58
  • 2
    Not always an option when you have a dog. Any encouragement to dig or slide under is ill-advised. I have a aluminum powder-coated fence. I try to go slow around the posts and make I am just barely touching the posts.
    – Evil Elf
    Commented May 22, 2013 at 13:21
  • Metal end-caps and shields as needed? Commented Aug 23, 2017 at 15:38

8 Answers 8


Agree with itsmatt's final solution, but there is another option. Because the fence is too close to the grass, you could excavate a narrow trench beneath, part fill with bedding mortar mix (about 1-2 inches deep, made with 4 parts sharp sand, 2 parts soft sand and l part cement) and then lay pavers in a row,or maybe 2 rows, so that the fence is sitting on those rather than the lawn. Once the bedding mortar has set (1-2 days, depending on temperature) then you'd need to point between them with mortar (3 parts soft sand, 1 part cement), brush dry into the gaps, then water gently over the top, so that you don't wash it out, and leave to set overnight. The mix beneath the pavers and the mortar mix will prevent grass coming up in between the pavers, so it's important that you do this.


Trimming along a wooden (or chain link!) fence is tough and tears up the wood undoubtedly. You can certainly try to do it more slowly and angle the string down toward the ground. That might help but there are a lot of variables here - the ground height, the movement of your arms, the amount of grass and where it is located, etc. - and that's only going to work so well. Plus, it takes a while.

I've seen folks slide old shingles, cardboard, carpet, etc. under the fence to essentially create a weed block. That will work but cardboard breaks down and none of these are all that appealing. You've got that nice fence there so you don't want to go junk it up with some junk laid under it. That's just my opinion.

You could cut a little off the bottom as ekaj suggested in the comment above. This might work well. It's a pain to cut pickets near the ground that are installed. A reciprocating saw (Sawzall is what they are called typically) would make quick work of this. You could cut them so there is 1.5 inches or so of clearance on the bottoms and probably keep the wood from being chewed up by the string trimmer in the future. That's likely one of the easier "one time" solutions to the problem.

Another possibility (though I try to avoid its use on our farm) is some sort of non-selected spray such as Round-up. That will definitely kill the grass and could be applied periodically. A more eco-friendly possibility might be vinegar (20% is available and is quite effective but requires some special handling (gloves, goggles) due to its caustic nature). Vinegar is moderately effective at killing weeds and is cheap (at least the 5% stuff is). These solutions - Round-up or vinegar - will result in a brown area along the fence line which might be undesirable.

You could decide to run a strip of mulch along the fence line. Put down some pro-grade weed fabric and and put several inches of mulch atop that to smother the weeds. Some of that push-in edging would give you a clean line to separate out the mulch from the grass. You could skip the edging but you'd probably end up with a fair amount of grass clippings in the mulch or shooting mulch all over the yard with the trimmer. They make that edging in plastic and in metal too. That's an idea. The problem with this solution is that (I'm assuming) if you share the fence with a neighbor, you've both got to be on-board with the solution or the weeds and grass are going to crop up on the other side anyway.

Personally, I'd opt to cut 1.5 inches off the bottom of the fence and be done with it. It's a one-time cost for the Sawzall, a couple hours of time to mark and cut the boards and then you are done.

  • Hell, just clamp a straight edge and use a circular saw.
    – Evil Elf
    Commented May 22, 2013 at 13:22
  • @EvilElf That would work too. I like it.
    – itsmatt
    Commented May 22, 2013 at 13:27
  • Thanks for the variety of options. I am hesitant to cut any of the fence as it is to keep my dog contained and doing so could encourage an escape :)
    – dpollitt
    Commented May 22, 2013 at 13:42
  • If your wood fence isn't at least a few inches OFF the ground it will rot. Ideally it should be 4". Makes far easier trimming. You could actually divide it up between yourself and your neighbors. In fact you had better talk to your neighbors before doing anything to the fence even if you installed the fence and paid for it all by yourself.
    – stormy
    Commented Mar 28, 2016 at 0:50
  • shoot...to make sure your dog is not able to crawl beneath and/or dig to get out, after cutting the bottom of simply install wire fencing, bunny fencing that is stapled to your fence and has been buried an inch or so beneath the soil. Easy to dig a little trench and then no worries.
    – stormy
    Commented Mar 28, 2016 at 0:53

The best thing to do would be to just create a mulched flower bed around the perimeter of your yard by the fence so you don't need to use your string trimmer up against the fence. It not only solves that one issue but it adds beauty, increases your property value and adds a little bit of isolation between you and your neighbors depending on what you plant.

Another option is to pick up a cordless string trimmer. They're not as powerful as gas ones and have thinner line. Might not do as much damage.

You could also try using a wide sheet of cardboard, plywood, or something to put up against your fence. It will slow you down since you'll need to keep moving it though.

I'm hesitant to make this next section without knowing which trimmer you own so here's a warning. Do this in a way that's safe, follow safety instructions and always wear long pants, safety glasses and other recommended protective equipment. Is there another guard, possibly third party you can purchase, or a way to reposition the guard at the end of your trimmer so that the guard covers the side of your trimmer? That way you put the guard side up against the fence and the line never touches it.

  • Thank you for your comments. I am strongly considering the mulch option, but I do have about 250 ft of fence so that would be a big effort. My trimmer is a pretty heavy duty Echo model, so moving the guard around is probably not a good idea due to the potential for debris.
    – dpollitt
    Commented Jul 1, 2013 at 19:35
  • I have both a gas and cordless trimmer and I've used electric trimmers in the past. The gas trimmers I've used have a lot more power and thicker line than the cordless ones. The cordless one trims just fine. Throttle back on the gas around the fence and be careful to minimize damage. Also call Echo see if they have an attachment or any recommendations. Maybe you can add a second guard on the side or something? Commented Jul 1, 2013 at 20:27

I'm also looking for a solution. Not just for that but to help ensure a consistent cut along edges I don't want to mark. For example, aside from slowly and tediously working my way along a white wall, I will mark it green from splatters of grass as the line hits the building.

I like my grass taller, and when I taper, blend or "fade" the edge it often makes for time consuming work

Materials are still in the works but for now I'm picturing a coat hangar that extends to the max distance of the trimmer line and dips so it can help hook the grass from the edge amd this ot to the edge of the spinning trimmer line.

This may also be helpful for picking out of chain link or even just as a guide to know exactly where your trimmer line is.

I've also seem guards that make the trimmer resemble a lamp, like the mouth of a trombone. I've seen it used for edging , At full speed the line is just bits apart from the rim, and spinning parallel. perhaps this would allow the closest access, like a bumper rim, but you'd have to be mindful of the angle youre using.


I have a pair of wooden 4x4 posts that are seriously beat up from my weed wacker, so I've decided to cut 6" tall x 3.5" wide strips of plexiglass and screw it on all 4 sides. At a distance the plexiglass is all but invisible and the new posts are not being chewed up by the weed wacker.


This might have been already suggested. Why not use steel edging? It comes in brown to match most cedar stained fences. If grass comes up between the edging and fence kill it with Roundup, etc. Your string trimmer will hit the edging and not your fence.


I live in Texas & in our subdivisions we have solid wood fences so that the fencing comes all the way down to the grass & there are no spaces in between the pickets. I discovered this method many years ago & it works perfectly. I never damage my fence, but I sure wish my neighbors would do this because they are cutting holes in my fence. What I do is use the weed eater as you would when you are edging the concrete walkway or driveway. So that the string is cutting up & down & not sideways. You can do it up close to the fence or what I eventually did was come out a few inches from the fence which also makes mowing easier.


Great answers...I thought of something else. Hey at one point in my life I thought about competing WITH my line-trimmer amongst other landscape maintenance personnel. We always got rid of the guard...I am not suggesting you do this. But the guard makes it very hard to become accurate with your placement.

My thought was to tell you to make sure the line is at the proper length. If it is too long you will have no accuracy at all and will eventually ruin your line trimmer. I was also used to a single strand of line, looped through a head you can switch for your automatic line head. So much easier. I pull the line ends together above the center of the head and clip...then I always turn the trimmer on edge and using concrete I allow the line to be further cut by friction on the concrete. This will ensure the lines are the perfect length. You'll hear the change in the motor as the line gets closer to perfect balance.

Gas tools are my preference. If one keeps the engine clean by changing filters, using good gasoline (no ethanol!!) and MEASURING when adding the oil to the gas...shake often to keep mixed and don't forget the filter in the gas tank...your investment will last longer than you. And don't LEND your family or friends your tools. Big mistake. 20 years ago I bought a used red max line trimmer. It was and has been the smallest yet most powerful line trimmer I've used. It still works well and it is over 30 years old. Wear ear protection and safety glasses over your prescription glasses. I've seen an eye lost because one of my guys took his glasses off when he went around the corner (he was new on my crew and it was some sort of macho-power-trip) and out of my sight...and I've taken out windows in 2 trucks...they were both mine. Line trimmers are very powerful and dangerous. Watch for hornets, grin! They HATE the sound of gas engines and will come right for you!

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