How to strim long grass with a petrol strimmer

We’ve all been guilty of letting the length of our grass get out of hand at times, especially over the winter, and it can be a bit of a conundrum when it comes to the best way to deal with it, without resorting to killing it all with weedkiller and then installing artificial grass.

Now, everyone knows that a lawnmower is the fastest way to cut your lawn, but they only perform at their best when the grass is at a medium height, and extra-long vegetation might need a different approach.

A good way to trim that long grass to a manageable size is to use a strimmer, but it has to be a petrol strimmer, as an electric or cordless strimmer just won’t have to power needed to get through it, and you’ll just find yourself screaming in frustration as your cutting wire snaps for the hundredth time.

In this article, we’ll walk you through how to strim long grass with a petrol strimmer, so you’ll feel confident diving in there, and all your grass-based nightmares can become a thing of the past.

Is it possible to use an electric strimmer to cut long grass?

While it is not impossible to do so, it will be extremely difficult, not to mention very slow going, if you attempt to cut long grass with an electric strimmer. Having said that, there are some heavy-duty electric and cordless strimmers on sale from brands like Makita and Stihl that would make it a bit easier. Still, they can’t compare with petrol machines for performance and will struggle a little with very thick grass, as this video shows-

How to use a petrol strimmer

Some people are intimidated by petrol-powered garden tools as they have heard that they can be hard to maintain, complicated to operate, and all sorts of myths that simply aren’t factual. While I will admit that using a petrol strimmer does take a little more knowledge and skill than operating an electric-powered or cordless one, it is not something that can’t be learned by anyone, and in a very short amount of time.
Read on below to find out the main things you need to know about petrol strimmers, and how to use them.

Safety equipment is essential

When using a petrol strimmer to strim long grass, you need to wear safety equipment. Please don’t take the risk and use these tools without a full set of equipment as accidents can happen at any time. Sometimes, on Amazon, you’ll find strimmers or brushcutters that come with free safety gear, but often it isn’t the best quality.

You’ll need a decent pair of safety glasses or a helmet with a visor to stop bits of debris flying up into your eyes, and ear defenders to deal with the noise. A decent harness will help handle the weight of the machine, and gloves, thick trousers or jeans, and boots are also required items. Just to prove that I take this stuff seriously, here’s a picture of myself and my neighbour greeting each other in our ‘safety gear’ 😂

2-stroke or 4-stroke?

All petrol strimmers are powered by petrol engines, but that engine could either be a 2-stroke design or a 4-stroke, with 2-stroke being the most common of the two. If I were asked which I prefer, I would have to say the harder to find 4-stroke models as they are easier to set up, and produce fewer fumes.

2-stroke engines are more popular because they are cheaper and you can get a lot of power out of an engine with a small displacement, and this is one of the reasons they are used on garden multi-tools. With 2-stroke engines, the engine oil and petrol have to be mixed together in the correct ratio before it is poured into the engine, but as most of these strimmers come with a free mixing and measuring bottle this is actually very easy to get right.

for those of you who like to go deeper into the differences between 2 and 4 stroke engines, there’s this clip-

How to start a petrol strimmer

Once you have filled the tank with the appropriate fuel from your jerry can, you should lay the strimmer on the ground and then locate the purge button. This is most often in the form of a rubber bulb, but sometimes it can be an actual button. The purpose of the purge bulb is to pump fuel into the carburettor and this takes more than just a few presses, usually closer to 10, but the instructions on your strimmer will let you know an approximate number.

After this is done, you need to open the choke all the way. This needs to be done every time you start the strimmer from cold, but is really simple, only requiring you to slide a handle or lever across in most cases. Finally, you can grab the starter cord and give it a few strong but smooth pulls until the engine starts. Once the engine has warmed up, you can close the choke.

It’s important to hold the tool down while you start it up, but obviously on the motor side and away from the business end if you value your fingers. A good pair of knee pads can come in handy if you’re going to be stopping and starting often.

How to strim long grass with a petrol strimmer

Before you attack the grass, go around the garden and remove any obstacles and hard objects that might be lying in there such as rocks and large stones, kid’s toys, garden furniture, and keep an eye out for hedgehogs. these little guys are often killed in power tool accidents involving overgrown vegetation.

You also need to know if your strimmer head turns clockwise or anti-clockwise, as this will tell you the best way to sweep the strimmer. I’d say most strimmers I’ve used go anti-clockwise and so I usually sweep from left to right, but if your spins clockwise you would sweep in the opposite direction, from left to right, and then release the trigger when swinging back in the opposite direction, a bit like this-

With this figured out and your strimmer started up, you can now attempt to cut the grass, but don’t just fly in there without a strategy. I’ve found the best way to deal with long grass, with a petrol strimmer, is to start at the edges and trim off the top few inches of the grass, trying our best to make sure that it is the very end of the cutting line that is making contact with the vegetation. I walk across until all the grass has been clipped a few inches, and then I go back and remove a few more inches. I repeat this until I have the desired length. You could always do this with a pair of shears, but I wouldn’t recommend it unless you’re a bit of a masochist.

Another method that I’ve used with success was to ‘dip’ the end of the strimmer in and out in a small arc through the grass, scything the top of the grass off, although I did find my arms getting more tired this way.

Once your grass is nice and short, you might want to think about making it look its best by putting some stripes on it. Wouldn’t you love something that looks like this-

About Terry Smith

I’m Terry Smith from, a professional landscape designer, hobbyist gardener, and barbecue fanatic with 20 years experience building and restoring. So as you go through my site you'll watch me document some of the professional garden installs I make as well as the major projects I take on at home. While sharing those experiences and guiding you, I'll be recommending some great tools I use to enable this along the way so you can really buy in confidence. Always feel free to pop me a message:

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