The optimum cutting height when mowing your lawn
While in other countries cylinder mowers are very popular, in German gardens it is primarily sickle mowers that are used as petrol, electric or battery-powered lawn mowers. These lawn mowers cut the grass with horizontally rotating blades. To ensure that this cut is clean and the grass blade does not fray, the blades of the sickle mower must be very sharp. Therefore, you should therefore sharpen the blades of your lawn mower at least once a year – either in your local workshop or with the help of a specialist dealer. Simply pick a few of the blades to check. If you see fringes and uneven cuts, the blade is blunt. Also make sure that the motor speed is high when mowing. The higher the motor speed, the faster the blades rotate and the faster they rotate, the cleaner the cut.
The cutting height on the mower can usually be adjusted in several steps. These steps do not usually translate 1:1 into centimetres, so step 1 is not necessarily 1 cm in cutting height. You can look up which step relates to which cutting height in the operating manual of your lawn mower. If you don't have it to hand, you can mow a small area – preferably in the shade – and then measure it.
For a normally used lawn, a cutting height of 4 cm is ideal. Shady areas should be mowed one to two centimetres higher. In this way, the grass will have more green stalk area for photosynthesis and it can cope with the reduced sunlight. Purely ornamental lawns can also be cut shorter to about 3 cm.
Too short a cut will damage the lawn, especially in dry periods. If it hasn't rained for a longer period of time, you should also leave some slightly longer blades of grass. If the grass is too short, the roots also suffer, as they are no longer protected from direct sunlight. Too short stalks and unprotected roots quickly dry out the lawn and turn it brown. In addition, further growth is an immense effort for grass that has been mowed too short. Mosses and weeds like to take advantage of this opportunity to displace the weakened grass plant in the garden and spread themselves. However, if you let the stalks get too long, you take away the stimulus for further growth and weeds spread.
Always follow the 1/3 rule when adjusting the cutting height. This follows the natural growth of the blade of grass by taking its vegetation point into account and is usually about half the height of the blade. If you also cut it, it takes a relatively long time for the shoot to recover and start growing again. If this happens, your garden lawn will become patchy. Therefore, it is recommended to mow a lawn that has grown longer, for example because of a longer holiday, in several stages so as not to cut off too much at once and to slowly shift the vegetation point back down again.