OMC blog article mowing on a slope

First things first, some ride on mowers are absolutely not suitable for mowing anything other than flat terrain. Be sure the mower you buy is built to handle slopes. Some can handle up to about a 15° gradient, others such as the Canycom are specifically designed for slopes much steeper. But even with one of these mowers caution should be taken. The following will provide you with some tips to help make the job a little easier and safer.

Firstly - Don’t mow when wet

Mowing flat wet grass isn’t ideal, and mowing a wet slope is an even worse idea. All the reasons why mowing wet grass on the flat isn’t ideal apply to mowing a wet slope with the added issue that you are far more likely to slip. A major hazard! Surprisingly, very dry grass is also not so safe and can be slippery and dangerous to mow but for different reasons. When the ground is very hard and dry, it does not provide the same grip that normal ground does ie. the tread slightly indents the ground therefore, giving more traction grip. The thing is, once you start to slip, you kick-start a chain reaction of physics principles and things can change, fast – it’s best to minimise the risk of slipping in the first place.

Shift the mowing deck up

Set your mower to a very high cut to avoid scalping the grass.

Think about using a self-propelled mower

If the slope you need to mow is not too big and you have a push mower, a self-propelled version makes it a little bit easier, especially for turns. Not needing to push it can help keep you from slipping.

Direction

For ride on mowers, go up and down (NOT side to side). This gives maximum traction to the drive wheels and lessens the risk of rolling. It also avoids the ‘crabbing’ that tends to happen when mowing crossways on any slope, where the heavy end of the machine keeps trying to slide downhill making slope mowing difficult.

Check before you mow

Do a pre-mowing inspection to check for and remove any big debris or obstacles (holes, ruts, bumps, rocks, sticks/branches, etc) that could get in the way. This is particularly important if the grass is quite long.

Tip – get yourself some tall bamboo poles, golf flags or other indicators, to place into large ruts or next to objects or debris that aren’t easily removed. Ensure these are visible before you start mowing.

Follow manufacturer’s directions

The manufacturer will know exactly what their product is capable of so read the manual and follow their recommendation before getting started.

ROPS (Roll Over Protective Structure)

Many mowers are issued standard with a ROPS. If your mower has a ROPS that is fully up (e.g. not folded down), then you must wear the seatbelt that is provided. If you don’t have a ROPS, it is not recommended to wear a seatbelt, as this makes exiting the machine difficult should you get into trouble. 

Go slow!

Choose a low or even the lowest gear and keep the RPMs up. 

Tractor Style Ride Ons

These type of ride on mowers are notoriously unstable on slopes for two reasons

  1. They have a pivoting front axle, which on slope allows the machine to automatically tilt over a bit and then that in turn causes a loss of traction on one of the rear wheels

  2. Due to the fact that the engine weight is in front, when going down a slope the centre of gravity changes. You then lose the ability to brake and slow down because almost all tractor style ride on mowers have only rear brakes.

Ride on slope and brush mowers

Slope and brush mowers have a very low centre of gravity and are often four-wheel drive for added traction. They ‘hug’ the ground and some can even mow slopes of up to 35°. Often called ride on brush cutters, their decks are designed to efficiently process long grass, high weeds and even small trees, with mulching or rear discharge output. They’ll leave a fairly reasonable finish but are not as suitable for flat, wide areas. Their lug grip tyres may rip up the turf (however, turf tyres are often available). Word of warning: don’t buy a model that has a belt drive deck and chain assist drive, they are nowhere near as safe.

Safety dos
  • When possible, always start, stop and turn on the flat.

  • Use extra care with grass catchers or other attachments as they affect the mower’s stability.

  • Have an escape route planned if the brakes fail or you lose control of the steering.

  • If you feel the front wheels lifting – STOP, turn around slowly and go back down.

  • Keep the brakes properly adjusted and maintained. Another note about the brakes, they are generally there to stop the mower not slow it down, that’s what the transmission is for. 

Safety don’ts
  • Do not shift to neutral and coast downhill.

  • Never use a rear-mounted bag on a slope as it gets too heavy and is a tipping hazard.

  • Never try to stabilise the mower by putting your foot on the ground.

  • Do not mow near drop-offs, ditches or embankments and also be careful near water edges, as it could be soggy and slippery.

If in doubt, don’t

In some cases the terrain may be too steep for anything. Perhaps fence it and get some sheep or goats, or landscape it to be a wilderness area or shrubbery. How steep is too steep? If your slope gains 30cm of height every 90cm of distance it’s too steep for your average ride on mower and you need a specialist mower.

If you’re still unsure about mowing on a slope, nobody has more knowledge and experience in this area than we do and we also stock a huge range of mowers all built to achieve different things. Download our handy guide to choosing the right mower for your property or get in touch with us and tell us what you need. We guarantee you’ll get the right one.

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DISCLAIMER

This article provides practical safety tips for using your ride on mower on your property. In no way are we allowed to provide legal safety information – for requirements and regulations relating to your mower, you should primarily consult:

  • The operator’s manual of the mower you have.

  • The agent who you purchased the machine off.

  • Worksafe New Zealand for Code of Practice, especially if in a commercial mowing situation.