The need to shorten the turf grass involves the use of a more or less elaborate machine, the mower. Indeed, manual mowing would not achieve the regularity of surface required for any lawn worthy of the name. A beautiful lawn must be short, regular and always green. If watering allows a regular growth of the grass and avoids its drying out, the mowing ensures the regularity that befits a lawn and prevents the formation of the flowering stalk. It also hinders its reproduction, which makes it necessary to regenerate the lawns periodically by carrying out complementary sowing, or even a total reconstitution, similar to their creation.
The different cutting systems
There are four main mowing systems today:
- the helicoidal blade cutter cylinder 3,5 or better yet 10 blades
- the rotating blade
- the rotating filament
The latter system was used until now for mowing finishes (which will be discussed later), but should soon be adapted to real lawn mowers.
The cutting cylinder
It comes in the form of a series of helicoidal blades that cut the grass very clearly by blocking it against an anvil (counterblade). This is by far the best cutting system, which, thanks to its precision, ensures immediate regrowth without intermediate yellowing. Collecting grass is however rarely possible with this type of machine, which implies a very regular mowing (every three days) during the growing season (May-June). The cut grass is then very thin, which makes it practically invisible. It is also an excellent green manure (but it must be ensured that its fermentation does not favor cryptogamic diseases).
The rotating blade
The rotating blade is the most widely used cutting system in continental Europe; it is also the most basic. A beveled blade at its ends, mounted parallel to the ground and driven by a motor, cuts the grass because of its speed more than the edge of its bevel.
The cutting is powerful (allowing a high grass mowing), but its quality is lower because the blades of grass are less well sliced than with a cutting cylinder and, therefore, frayed, hence a risk yellowing between mowing and regrowth. Machines equipped with this system can almost all be equipped with cut grass collection equipment.
The mower represents the most basic and traditional mechanical means for cutting grass. It is not actually a mowing tool, but rather a way of cutting grass, such as a lawn meadow, when its height may turn it into a field of hay grass. Its operating system is based on the principle of the cutter bar used most commonly in agriculture for mowing the grass of the field, the mower consisting of a number of pointed fingers slightly bent upwards and a blade in saw teeth which, by a very fast transverse movement, cuts the grass caught between the fingers, in the same way that a hairdresser mower cuts the hair.
Rotating filament is the latest in cutting systems. It is usually a nylon wire rotated by a motor and, because of its speed, cuts the grass parallel to the ground. This cut, we imagine, is even less precise than the systems mentioned above. The rotary filament has so far only equipped lightweight machines consisting of a handle and a small motor, to access where the mower could not go (along a wall, around a tree, a pole, etc.); the appearance of models with high-power engines and high efficiency (up to 50 cm wide) classify them as complementary mowers. Several manufacturers have also studied the adaptation of this principle to real lawn mowers, because the nylon filament has the advantage of not being damaged like a blade when it encounters an obstacle (stone, small stump, etc.): indeed its very principle being to wear, its replacement is done manually or automatically from a reserve included in the device.
The different types of machines
The evoked cutting systems can be moved in different ways, both as regards the actual cutting as the progression (traction or propulsion) of the machine.
This is how we will find lawnmowers:
- by hand, which is pushed in front of you, whose cutting system is the cylinder with helical blade
- electric motor (sector or battery) with power between 800 and 1500 watts using rotary and filament blade systems
- with thermal engine (2-stroke and 4-stroke), which are associated with the rotary blade, helical blade, cutter bar and, recently, filament (some machines are already operating in the US, they require of course a very fine turf).
Which lawnmower to choose?
Everything that has just been written is puzzling to the amateur gardener who for the first time decides to create or maintain a lawn. The ideal machine is the one that best fits the type of grass, the surface and terrain, the requirements and possibilities (time) of the gardener.
In general, we can consider that a fine turf corresponds to a very neat lawn deserving a high quality cut; in this case, only the mowing cutter can be suitable.
The area Terrain will be critical in your choice of mower power source.
The hand mower can only be retained if your lawn is very small (less than 200 m2). Choosing a lawn mower
|Maximum area||200 m²||400 m²||600m²||800m²||1000m²|
|Nature of the grass||Grass||Grass||Grass||Grass||Grass and grass|
|Type of engine||-||Electric||Electric||Electric||Thermal 2 or 4 times|
|Power||500W||800W||1200W to 1500W||3 HP (about 2237W)|
|Cutting member||Cylinder||Rotary blade||Rotary blade||Rotary blade||Rotary blade|
|Cutting width||30cm to 40cm||30cm to 40cm||30cm to 40cm||30cm to 45cm||45cm|
|Start-up||Light switch||Light switch||Light switch||Launcher|
|Maximum area||1500 m²||2,000 m²||5,000m²|
|Nature of the grass||Grass and grass||Grass and grass||Grass and grass||Grass or grass||Grass|
|Type of engine||Thermal 2 or 4 times||Thermal 4 times||Thermal 4 times||Thermal 4 times||Thermal 4 times|
|Power||4VC||5CV to 6CV||6CV to 7CV||8CV to 11CV|
|Cutting member||Rotary blade||Rotary blade|
|Rotary blade (s)||Rotary blade (s)||Several cylinders|
|Cutting width||50cm||50cm to 60cm||60cm to 70cm||70cm to 100cm||120cm to 140cm|
|Start-up||Launcher or Switch||Launcher or Switch||Launcher or Switch||Light switch||Launcher|
You have better choose a lawn mower electric motor if your pitch is between 200 m2 and 600 m2 and that the farthest mowing area is less than 50 m from the feeding point (unless taking a battery model).
From 600 m2, choose a lawn mower thermal motor, to push up to 1,000 m2, propelled or self-propelled up to 2,000 m2, Lawn (mini tractor) beyond.
For mowers other than on-board lawn mowers, the choice between 2 times (mixing) and 4 times (gasoline) is not just a matter of taste. The first are less noisy, but more polluting, and are suitable for sloping terrain, 4-stroke engines losing oil in the crankcase as the inclination increases. For steep and particularly uneven terrain, choose a 2-stroke or electric air-powered lawn mower.
Finally, for very large areas, we will choose, if the condition of the grass and the terrain allows, a mower with helical blades with high efficiency (up to 1.50 m wide) and 4-stroke engine high power or a micro-engine diesel engine, always more economical than gasoline engines, but infinitely more expensive to buy. Both solutions can only be considered if you have between 5 000 and 10 000 m2 (1 ha) of mowing grass, which is rarely the case.
The time that you have for mowing a lawn is also an important factor in choosing between the different types of machines mentioned. It goes without saying that a small machine (cutting width of about 40 cm), low power (3 hp or less), not self-propelled will not be suitable for a large lawn: mowing would then require a lot of time and physical effort. So here, obviously, the budget that you can spend on the purchase of mowing equipment, the mower price range easily ranging from 1 to 30 (between a hand mower and a high-end lawn tractor).
(photos / visuals: © DIY PROD, except special mention)
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