Mowing the lawn – when and how often?

Mowing the lawn is probably the most well known of all lawn care jobs but it is still carried out incorrectly by many lawn keepers. To develop and sustain a top quality lawn you need to know when and how often you should mow the lawn. Mowing too often or at the wrong times can seriously degrade the condition and vigour of the lawn.

The aim of mowing the lawn should be to keep the grass somewhere inbetween 'not to long' and 'not to short'. If the grass is too short then the roots will not receive adequate food and the ability of the lawn to take up nutrients and water through the roots will decline which in turn will result in poor growth rates and a loss of vigour. If the grass is too long then the lawn will look a mess. Mowing the lawn helps to stimulate side shoot development in the grass and this leads to the build up a dense lawn that has a strong growth rate.

Lawns should be cut during spring, summer and autumn. If you are having a mild winter then it may be necessary to mow the lawn on the odd occasion over winter.

You should always aim to mow the lawn when the grass is dry as the blades will cut the grass better. If you mow the grass in wet weather then the weight of the mower and your footsteps will result in muddy patches appearing and the soil surface will become compacted. The grass will find it hard to re-establish itself on these areas.

Drought and other environmental stresses can cause the grass growth to come to a near stop in the ‘growth seasons’. If the grass is not actively growing or its growth rate is much reduced due to conditions such as drought then do not mow the lawn.

How often the lawn needs mowing will also depend on what grass types your lawn is made up of. High quality ornamental lawns made up of fine grass types can be cut every 3 days or so in rapid growth conditions. The grass on these lawns tends to be kept quite short. Utility lawns with broader, longer grass types should be cut around once a week.

How heigh should I mow the lawn?

The height at which many lawn mowers cut can be manually adjusted. The height at which you cut the lawn is dependent on what type of lawn it is and the growing season.

For ornamental lawns the height of the cut should be about 0.75cm in early spring, autumn and winter and between 0.3 – 0.5cm in mid-late spring and summer. If a top quality ornamental lawn is not kept at the correct height then the balance of grass varieties that make up the lawn will change and longer broad leaved grasses will start to dominate.

Utility lawns should be cut higher, - around 2 – 2.5cm during the more rapid growing seasons of spring and summer and about 3-4cm. If the grass is cut too short then the grasses are greatly weakened, growth slows and the grass density declines. This open turf is then much more susceptible to invasion of weeds and moss.

Shady lawns should be cut less frequently then lawns that receive good levels of sunshine. Grass types that are found in seed mixtures for shady lawns tend to be happiest when at lengths of over 2cm. A shady environment will also slow growth rates when compared with a sunny environment.

See creating lawn mower stripes for advice on getting that perfect striped appearance and other useful mowing practices that will help prevent any unsightly glitches to your lawn’s surface.