Will A Pressure Washer Get Rid Of Flies In Hedges

Once you own a pressure washer and you’ve been using it for a while, you’ll realise just what a handy piece of kit it is. Not only handy, but pressure washing is also great fun and very satisfying. Suddenly every task that needs to be done, you’ll be reaching for the pressure washer. 

When the only tool you have is a hammer, you start to treat everything as a nail”

Owning a pressure washer has finally made sense of that old quote, we find we’re constantly on the lookout for new excuses for getting the pressure washer out. We’ve exhausted all the usual excuses, the cars gleaming, the drive is the cleanest, the most weed-free drive in the area, the windows and fascia have never been cleaner. Even the garage floor is grease and oil stain-free!

Using A Pressure Washer To Get Rid Of Whiteflies

So what next? After reading a recent gardening publication, we got to thinking about using the pressure washer to get rid of flies in the hedge. There’s a chap in Arizona who’s battling against a whitefly infestation in his weeping fig (ficus Benjamina) hedging. These insects hide on the underside of leaves and enjoy plants that are covered in dirt and dust.

He explains that his first task in the removal of the whiteflies is to blast the plants with a high-pressure jet nozzle making sure he gets the underside of the leaves. Then he uses the jet wash to get right into the middle of the plants and spraying upwards, he makes sure he’s got them all. He then uses an insecticidal soap to kill any eggs or whitefly nymphs.

Is It Safe To Use A Pressure Washer On Plants?


After some more research, it turns out that weeping fig plants only grow in tropical and sub-tropical conditions but are vigorous plants with a very strong, sometimes invasive root system. So a very robust plant under suitable growing conditions, not necessarily anything like our hedge which is mainly privet (Ligustrum ovalifolium). Which leads to the question is it safe to pressure wash our hedge?

We found another article on why not to use a pressure washer on trees, and it made a compelling argument.

Why It’s Bad To Pressure Wash Trees

Let’s start with the difference between a garden hose and a pressure washer. When it comes to force, a garden hose exerts around 50 Pounds per Square inch (PSi) while the pressure washers force ranges between 1,000 PSi and 4,000 PSi. That’s a considerable amount of extra pressure, and plants are in many ways like us. They can get hurt by too much pressure.

Depending on the type of tree and the level of pressure you exert, the outer layer of bark can be removed. And the tree can suffer internal molecular damage at the cell level. Plus too much pressure could rip all the leaves from the tree, which will cause it to die from lack of photosynthesis.

So while a pressure washer is great for many cleaning tasks, and also for removing weeds from driveways, when it comes to insect infestations on your hedge plants, don’t be tempted to reach for the pressure washer. That’s not to say a pressure washer won’t get rid of flies from the hedge, it probably will but it’ll also get rid of the hedge too.

How To Get Rid Of Flies In The Hedge

Flies of all type are on the lookout for food, water and shelter just like us, but unlike us, many flies eat disgusting stuff. Like:

  • Rubbish
  • Rotting meat
  • Excrement
  • Sweat

Due to their diet flies can spread an enormous range of illnesses and diseases including:

  • Eye infections
  • Skin infections
  • Diarrhoea
  • Polio
  • Cholera
  • Typhoid
  • TB
  • Dysentry
  • Diptheria
  • Anthrax
  • And many more

And that’s just houseflies!

Steps To Remove Flies From Bushes

The best way to get rid of flies from the hedge is to:

  1. Keep the undergrowth tidy
    Remove all litter and rubbish as soon as you spot it.
  2. Remove all excrement
    Keep an eye on pets’ toilet habits and clear up after them immediately.
  3. Top dress the soil
    Cover the soil with a good mulch to prevent flies from breeding under hedges.
  4. Only use compost
    Or well-rotted manure to fertilise your hedgerow plants.
  5. Remove any standing water
    Flies need water too, remove any cups, buckets, small containers etc that could contain rainwater etc.
  6. Remove any decaying fruit
    Or vegetable matter from beneath the hedging plants to prevent attracting any insects.

How To Deal Other Problem Flies

Aphids (greenflies and blackflies) are a common problem in hedgerows. To get rid of aphids try encouraging natural predators like hoverflies and ladybirds to the garden. Or, if you’re not too bothered about using chemicals, there are plenty of poisons that can be bought from garden centres to get rid of aphids.

Gnats can also be a problem, by removing standing water you effectively remove gnats and mosquitoes breeding ground.

If you seem to be inundated with a host of flying nuisances consider putting up a fly zapper, there are battery operated fly zappers around now that will help control the fly population. You could try fly papers too but these are messy and sticky, so take care if you have children.

The Bottom Line

Unless you have incredibly strong plants in your hedgerow, or you don’t care if they live or die, it’s not advisable to use a pressure washer to get rid of flies. Even at the lowest PSi, your pressure washer will do irreparable damage to your plants. Always keep on top of tidiness, remove any rubbish or decaying fruit and vegetative matter, and remove any feces and standing water.

If you’re looking for advice on which pressure washer you should purchase, be sure to check out our guide here.

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