Are Hedge Trimmers Bad for Plants? – Common Mistakes Explained

Approx Reading Time: 8 minutes

If you are a homeowner, you will almost certainly have some plants in your yard.

But growing and owning different plants can be a daunting task.

Hedges, shrubs, flowers, you name it; all of them require proper maintenance and care.

And the easiest way to keep them nicely manicured is by using a hedge trimmer.

However, are hedge trimmers bad for plants? A hedge trimmer in and of itself is not bad for plants. What makes a hedge trimmer bad is its condition and the way it is used. Also, using power hedge trimmers on their own can be bad as it can lead to external overgrowth and empty plant structure on the inside.

With that being said, I do realize that you may have more questions as to how exactly can a hedge trimmer cause harm to your plants.

This is why below, I share with you more valuable information about everything you need to know.

What Plants Can You Trim With a Hedge Trimmer?

Hedge trimmers are a multi-purpose tool. They can be used to trim hedges, shrubs, rose bushes, overgrown grass, weeds, and so much more.

First, we need to establish a few distinctions. There are a few different types of hedge trimmers.

  • Power hedge trimmers ( corded, battery, and gas-powered ); and
  • Manual hedge trimmers (read hedge clippers or shears).

Both types have their use and purpose.

Electric and gas hedge trimmers are used on bigger hedges, bushes, and plants. They are suitable for large amounts of trimming, formative and restorative pruning.

Manual hedge trimmers, on the other hand, are best used for shaping and adding some final touches to the plants.

Hedge trimmers can undoubtedly damage a plant, but that does not necessarily make them bad. Plants need to be trimmed and pruned every once in a while in order to stay healthy.

Again, a hedge trimmer in and of itself is not bad for the plant – what makes a it bad is its condition and how it is used.

What Makes Hedge Trimmers Bad for the Plants

Let’s look into the main reasons a hedge trimmer can cause harm to your plants:

Not Following the Safety Precautions

Before using your hedge trimmer on your overgrown hedges and shrubs, take some time to familiarize yourself with the proper way to use and operate it.

Always follow the general safety precautions.

  • Make sure always to maintain and keep a stable balance;
  • Hold the hedge trimmer with both of your hands for more control over the tool;
  • Mind any rocks, uneven grounding, wires, thick branches, fences, etc.;
  • Do not stand on wet or frozen ground; and
  • Make sure to wear hand, eye, and ear protection. Wear safety, non-slip shoes, and appropriate work clothing.

All of the points mentioned above are important not just for your safety but for the safety of your plants too.

Losing your footing as a result of slipping on wet ground, or tripping on a rock can result in more than a personal injury. Even slight loss of control over the hedge trimmer can result in uneven, deep, and unhealthy cuts that will be bad for the plant.

It does not take much for the powerful trimmers to cut through a hedge or a bush, and this is why exercising extra caution is advised.

Not Following the Proper Trimming and Pruning Techniques

The next step is to always follow the proper techniques for using a hedge trimmer.

Generally speaking (unless you are into topiary), you will be trimming your hedges in two axes: vertically and horizontally.

  • When cutting a hedge vertically, make wide sweeping arc motions that start from the bottom and reach the top; and
  • When cutting a hedge horizontally, use the same sweeping motion starting from the outer edge of the plant.

The rule of thumb is to always keep the top of the hedges narrower compared to the bottom. This allows the bottom parts of the hedge to receive enough light and grow properly.

Never cut too deeply into the plants. Start with shallower movements and trim the plant gradually, cutting only small amounts of it. Digging into the plant and cutting large parts of it is both bad and unsightly.

For more info on what are the best trimming and pruning practices, check out this video below.

Alternatively, you can check out this article I wrote on pruning hedges to grow fuller.

Operators that have never used a hedge trimmer before may find it harder to maneuver and control the hedge trimmer at first, which can result in trimming of varying quality.

This is why inexperienced users are recommended to trim their plants slowly and in a controlled fashion.

Many people can get a little carried away, but remember never to cut more than 1/10 to 1/3 of the plant. Removing large parts of the plant can be so bad for it that it may never be able to recover.

Another way hedge trimmers can be bad for plants is when they are used to trim the outer parts of the plant. This encourages external but not internal growth. Given enough time, this will lead to essentially hollow brown and bare branched plants on the inside.

This is why it is recommended to follow up with some manual pruning with some shears.

The aim of pruning is to remove damaged or diseased parts of the plant and allow for more light to enter the plant. This will stimulate the internal growth of the hedge, and overall, you will end up with one healthy looking plant.

Not Taking Care of the Hedge Trimmer

The first thing any owner of a hedge trimmer needs to do is keep the trimmer clean. You want to clean it properly after each use.

Clean hedge trimmers work better and produce cleaner cuts that will not damage the plant in any way.

Another thing is disease control – hedge trimmers can spread disease in two main ways:

  • Directly – Hedge trimmers can quickly spread disease if they have been used on an already infected plant; and
  • Indirectly – Cutting your plants when the weather outside is wet is dangerous as it can spread disease as well.

If you have used the trimmer on a diseased plant, make sure to clean it thoroughly before moving on to trimming other healthy plants.

Cleaning the trimmer with soapy water or water with a little bleach can help getting rid of the germs and mold.

The next thing is always to keep the blades well-sharpened. Dull blades will have difficulty cutting through the plants.

The trimmer will be twisting and pulling on the branches, and this will leave a lot of bad unclean cuts and shredded stubs. Such branches and stubs can be very bad because they can introduce disease and fungi to the plant.

If you want to learn how to sharpen your hedge trimmer, check out this article I wrote on this very topic.

To a certain extent using a manual trimmer can be better for the plant because you can make more precise and healthy cuts that will health faster.

Last but not least, you want the blades of the hedge trimmer to always be well lubricated. Use some light machinery oil or WD-40 on them.

A well-lubricated trimmer will be easier to use as it will prevent any lock-ups and will not damage the plants.

Using the Hedge Trimmer at the Wrong Time

A hedge trimmer can also be bad for your plants by being used at the wrong time.

  • Formative pruning – Newly planted hedges require formative pruning while they are still young. The purpose of formative pruning is to develop the right shape of the hedge. During the first couple of years, hedges are best trimmed during the late winter or early to mid-spring.
  • Maintenance trimming – Very light cutting and trimming may also be required during the late spring and summer if the hedges are getting out of control and growing too fast.

Do not prune your hedges, shrubs, and bushes if it is wet outside. And if it has been raining for a while, wait until the plants have dried out a little before pruning or trimming them.

Water and moisture creates the right environment for microbes, bacteria, and mold to grow and spread, and working on your plants while they are still wet can introduce disease to them.

Peter Toth

Hi! I'm Peter, the owner of BackyardGadget. Working around the house has always been a big part of my life. I've created this site to share my experience, and to help people choose the right tools for the job. Thank you for stopping by!