Reading and questions about safety

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This unit standard is for people working or intending to work in amenity horticulture. People credited with this unit standard are able to use and maintain small, powered amenity machinery and equipment.

You will learn how to select, operate and maintain the right machine for the job.The following equipment will be used to best prepare you for work in the horticulture industry.

  • Two stroke rotary mower
  • Four stoke rotary mower
  • Line trimmer
  • Hedge trimmer
  • Cultivator (rotary hoe)
  • Blower
  • Water blaster


Read the following information and answer the questions in relation to the selection, application and safety requirements of the machinery and equipment you are likely to operate when working in the horticulture industry.

  • Read the manufacture’s manual and listen/apply trainer’s or employer's instructions.
  • Never fill the fuel tank indoors, or when the engine is running. Do not smoke when filling the fuel tank. Re-fuel away from your current working position.
  • Observe health and safety rules particular to the site you are working on.
  • Wear personal protective equipment (steel caps, hearing protection, sunscreen, eye protection, long trousers/protective chaps, long-sleeved shirt, and hi-visibility vest).
  • Do not use machinery when under the influence of any drug or fatigued in a way that may impair judgement.
  • Learn how to quickly stop the machine in an emergency.
  • Keep hands, feet, hair and loose clothing away from any moving parts on engines and equipment.
  • Be aware of any people in the area and ensure they are at a safe distance before operating the machine.
  • Ensure equipment is in good order (no loose or worn parts) because damaged blades and worn bolts can be a hazard.
  • Ensure safety guards are in place.
  • Use the machine for the purpose it was designed for.
  • Don’t alter or adapt the machine in any way.
  • Disconnect the spark-plug leads before servicing any moving parts and before cleaning blockages.This will leave no chance of the engine starting with you working on it. It is better to loose a few second than loose a few fingers!
  • It is advised to wear some gloves and eye protection when servicing and refueling machinery to help prevent petrol and/or bits of debris getting in your eye.

Answer the following questions

You are dressed in a T shirt, shorts and sneakers.What would you put on before operating any motorized equipment?

What would you always disconnect before servicing the moving parts of motorized equipment and why?


The three main types of small powered mowers used in amenity horticulture are:

  • Reel mowers (4 strokes). Reel mowers are good for mowing fine turf lawns and fine turf playing surfaces such as golf greens. They are not suited to steep sites as the rear roller tends to slip. Wet grass can also be a problem as the cutting blades tend to clog, making cutting less efficient. They are mainly used on smaller areas.
  • Rotary mowers (2 or 4 stroke). Rotary mowers are good all rounders and can be used on amenity turf areas and lawns where the finished cut is not as critical as on a fine turf lawn. They are also useful for mowing under trees or around other objects in a lawn because you can cut close to the object without causing damage. Rotary mowers are easier to move around and lift than a reel mower.
  • Air-cushion rotary mowers (commonly called “Flymos”) Air-cushion mowers have two-stroke engines which are light and can be used at steep angles. They can also be useful if the area you are mowing is wet as they hover above the ground and will not leave unsightly wheel tracks.

Cutting Action

  • Reel Mowers –The reel consists of a number of spiral blades fastened to flanges mounted onto a central shaft. Because they are mounted spirally, the blades cause a progressive cutting action across the leading edge of the bottom plate, also called the bed knife or sole plate. A scissor action is achieved.
  • Rotary Mowers – The grass is cut on impact by a blade rotating at high speed. The cutting blade is powered directly by the engine.
  • Air-Cushion Rotary – Single blade and the same action as a rotary mower. The only difference being that an impeller is attached in the center of the blade that sucks air in and presses it to the edge channels of the hood forming a cushion of air to lift the mower off the ground.All safety precautions should be taken as for other mowers, but because the air cushion can be used on steep banks you must have a solid footing to avoid slipping into or under the mower.

Safety with Mowers

Observe standard small machinery safety, and:

  • Always wear recommended PPE.
  • Before mowing, inspect the area to be mowed for objects that may become tangled in the blades.
  • Before mowing, inspect the area to be mowed for rocks,sticks,toys or any foreign objects that could cause damage to the mower blades or become a projectile.
  • Turn off the motor before removing the catcher.
  • Disconnect the spark-plug lead before servicing any moving parts.
  • Never cut grass while walking backwards.
  • Stop the engine before pushing the mower across gravel drives, walks or roads.
  • Mow across the face of slopes, never up and down.
  • Do not re-fuel machine near open flame, sparks or any material that could cause the fuel to ignite.

Answer the following questions

Explain the difference between the cutting action of a rotary mower and a reel mower.

Which type of mower would be suitable for the following jobs?

  • Mowing small areas of lawn where the finished cut is not critical.

  • Mowing steep banks.

  • Mowing fine turf lawns such as a bowling green.

  • Mowing low maintenance areas where the finished cut is not critical.

Cabbage tree leaves have become tangled around the blade and shaft.What should you do before attempting to remove the leaves?

Why is it important to keep a record of how many hours motorized machinery has been operated?(Hint-see following section on operation and servicing)

Why is it important to maintain motorized machinery as per the manufacturer's recommendations?

Line Trimmers

There are three main types of line trimmers:

  • Light weight models for the home gardener - these consist of a small 2 stroke motor mounted on a shaft with a rotating head at the other end, containing light nylon, which does the cutting as it spins.Light weight models are used mainly on small areas around the home,for example, turf edges along concrete paths and around trees. They are not designed for longer grass because the small engine tends to stall and the cutting head becomes clogged.
  • Industrial line trimmers (weed eaters) – these are powered by a large engine, have heavier line, and are built from more sturdy material than the domestic models, because of the extra weight, a shoulder harness is worn by the operator and is connected to the machine. The harness distributes weight to the shoulders of the operator so that the machine can be used for long periods in relative comfort. These machines are used for larger areas and long unkempt grass in disused sections or where there is unsuitable access or steep terrain where conventional mowing equipment may be dangerous to operate.
  • Industrial brush trimmers – these are the same machine as the industrial line trimmer, but the line head is replaced with a circular serrated-edge steel blade. Two blades area available, one for long grass and one for woody weeds such as broom and gorse.

Safety with line trimmers and brush cutters

  • Observe general rules for small-powered machinery but also observe the following:
  • Always wear eye protection, gloves, safety footwear, hearing protection, protective clothing.Chaps are recommended especially if you are using a blade or other attachment, for example a hedge trimmer attachment.
  • Remove stones and other foreign objects from work area before cutting.
  • Watch your footing and don’t over-reach.
  • Keep both hands firmly on grips.
  • Try to trim from left to right, allowing debris to be thrown away from the operator.
  • Stop engine to clear clogged cutting head, or if your machine becomes entangled with a foreign object.

Answer the following questions

Which line trimmer would be most suitable for the following jobs?

  • Cutting down grass around the average home garden.

  • Cutting down gorse and broom, with a stem diameter of up to 2.5 cm.

  • Cutting down long grass and light scrub.

Before trimming grass in an area, what should you check the area for?

What should you do if the cutting head needs untangling or clearing?

What should you wear when operating a line trimmer?

Hedge Trimmers

Motorized hedge trimmers – there are two types:

  • Electrically powered – electric trimmers are powered off 240 volts mains power and require an extension cord and an isolating transformer to be operated safely. The use of an extension cord limits their use to smaller areas close to a power source; for this reason they are mainly used by home gardeners.
  • Motorized hedge trimmer – there are two blades, one stationary and one powered by the engine which moves back and forth, scissoring plant material between it and the stationary blade. This machine should only be used to trim hedges and to cut plant material with a diameter no larger than is recommended by the operating instructions as anything greater than this can damage the cutting blade and clutch assembly.

Safety with Hedge Trimmers

  • Observe the standard safety precautions that apply to small motorized equipment plus the following:
  • Wear eye protection, hearing protection, gloves, safety footwear, long-sleeved shirt, and chaps.
  • Don’t wear loose clothing.
  • Inspect area to be cut for obstacles, e.g. wire, concrete posts.
  • Hold handle grips firmly.
  • Maintain firm footing and don’t over-reach.
  • Don’t use the machine above your head.
  • When cutting the lower portion of a hedge, avoid the cutting blade contacting the ground, as this may cause a kick-back action.
  • Always position yourself so that the cutting blade is moving away from your body.

Answer the following questions

Which hedge trimmer would be most suitable for the following jobs?

  • Trimming a large macrocarpa hedge which is surrounding a sports ground.

  • Trimming a low hedge in a small suburban section which has a nearby power source.

Before trimming a hedge, what should you inspect the hedge for?

What PPE should you wear when operating a hedge trimmer?

Cultivators Rotary Hoe

Types of powered cultivators used for cultivating soil

  • A rotary hoe used for small areas has rotating tines on an extended arm in front of the power unit.
  • For slightly bigger areas (1/4 acre or 750 sq m.) the power unit is mounted over the tines as this provides for more weight over the tines which enables firmer soil to be cultivated.
  • The third type has the tines mounted to the rear of the power unit and is used for heavier work in areas greater than 750 sq m. It is a more stable machine than the smaller models.

Safety with Rotary Hoe

  • Observe safety precautions that apply to other small powered machinery.Also pay attention to the following before commencing cultivation:
  • Check for underground services (power wires, water, gas pipes and drains).
  • Remove obstacles from the area, e.g. bricks, large rocks, wire, etc.
  • Select a suitable machine for the soil conditions.
  • On uneven, or sloping ground, the machine may tip up. Move up and down the slope, not across it.
  • Don’t clear debris while the machine is running. Turn it off and remove the spark plug lead.
  • Avoid obstacles such as concrete paths, buildings and fences. If the moving tines contact solid surfaces, it causes the machine to bounce and buck which could result in the machine tipping.
  • Disengage tines before moving to a new area.

Answer the following questions

Which cultivator or rotary hoe would be most suitable for each job?

  • Cultivating a large area (over 750 square meters) with heavy, lumpy soil.

  • Cultivating a small vegetable garden in a suburban garden.

  • Cultivating firm soil for an area of about 750 square metres.

What should you do if debris becomes entangled in the tines of a rotary hoe?

Explain why it is safer to rotary hoe up and down a slope and not across it.

Before rotary hoeing an area, what must you check for?

Operation and Servicing

  • The safe operation and servicing of machinery will take place in practical sessions which are scheduled in your timetable.
  • In most places of employment which includes self employment,you will be required to record the amount of hours you have used a machine so that the manufacturer’s maintenance requirements can be followed to maintain the machine in good order and prolong the longevity of machinery.It is important to keep accurate records so the employer can also determine depreciation, when an item of equipment needs to be replaced, and its potential re-sale value.
  • In order to get into the habit of filling in a log book there will be one available for every machine and could include the following details: type of machine,length of time operated,where machine was used,any problems you may have experienced with the machine, how these are to be corrected and a record of any servicing carried out.


Below is a list of resources related to our practical learning activities.

DAT for Numeracy

  1. A ratio is a way of comparing quantities. True/False
  2. The general convention is to get your ratio to a reduced form.True/False
  3. How do you get a ratio to a reduced form?
  4. You can use more than two quantities when expressing a ratio.True/False
  5. Hortykim has asked you to mix some two stroke fuel for the two stoke lawn mower using 1 part of two stoke oil to 50 parts of premium fuel.Write this as a ratio.
  6. Hortykim has asked you to mix some two stroke fuel for the two stroke lawn mower using 50 parts of premium fuel to 1 part of two stroke oil.Write this as a ratio.
  7. Print off this worksheet,answer the questions and submit to hortykim to see if you answered the questions correctly.
  • Watch this video of hortykim and students using the fuel mixing chart to make up 2 stroke fuel mixtures for the different machines we use in horticulture.

DAT for Literacy

  • When we are learning about the operation and maintenance of small machinery it is likely we will encounter some terms or words that we are not familiar with.Please have a look at the following terms and see if there are any you have not encountered before:
  • Terms associated with lawn mowers


Operation manuals

Scan operation manuals and upload as PDFs here.