Landscaper Pro Advice : Mowing – the fundamental turf maintenance operation

Mowing is the fundamental turf maintenance operation and the most frequent task that needs to be completed on a lawn to keep it in good condition.  It can have a significant effect on sward composition, quality and presentation as well as on the development of roots and shoots and so the density and wear tolerance of the surface.  For a first class surface you need to get the mowing right.

What height of cut? -

Different heights of cut favour different grass species. Prolonged cutting too low will weaken any sward and give rise to an increase in the presence of moss, annual meadow grass (a weed grass) and low growing weeds such as pearlwort (Sagina procumbens) and dandelion (Taraxacum officinale). However, leaving the grass too long will encourage coarse grass species and result in a more open sward with poor density giving opportunity for upright weed species to invade and leaving the sward susceptible to disease infections.

The height of cut should be varied across the year to take account of prevailing weather conditions and the rate of growth.  In general the grass should be kept shorter during the summer when growth is stronger and sunlight levels are favourable, although you should always try to increase the height of cut during periods of prolonged hot and dry weather to help minimise stress.

The following table shows the recommended mowing heights for the LandscaperPro range of Grass Seed Mixtures.

How often should you cut?

Ensuring that the grass is cut frequently enough to keep up with growth should be considered of equal importance to choosing the correct mowing height.  More cuts will be required during the spring and summer (weather dependant) compared with late autumn and through the winter.  As indicated in the table above, growth should not be allowed to get away from you which will only result in a poor quality of cut and excess clippings. No more than 1/3 of leaf tissue should be removed in a single operation.

Tips for top quality lawns

Vary cutting direction: The direction in which the grass is mown should be varied at each operation to prevent the formation of a ‘nap’.  This is where the grass starts to develop a unidirectional and flat growth habit which is unattractive and increases the vulnerability of the sward to wear.

Remove clippings:  Depending on the quality and size of the facility a decision will need to be made as to whether to let clippings fly or box them off.  The removal of clippings will prevent nutrients from being recycled and result in a higher level of fertiliser being required to maintain healthy growth.  Letting clippings fly will give a more drought resistance sward with a good colour through the summer although the grass will be more vulnerable to disease infections and ingress by weeds, annual meadow grass and worms in the long-term.

Cut when dry (if possible): Ideally grass should always be cut during dry conditions although it is appreciated that this is not always possible.  Mowing when the grass is dry will ensure that the mower performs at its best, giving a clean cut and good levels of presentation.  Cutting when wet will increase the tendency to ‘tear’ thereby reducing presentations levels and leaving the plants vulnerable to disease infection.

Selection of Mowing Equipment

Cylinder Mower vs Rotary Mower?

Cylinder mowers have a rotating cylinder of sharpened blades acting together with a fixed bottom blade or sole plate to create a ‘scything’ effect.  The number of blades within the cylinder will dictate the quality of cut produced.  A higher number of blades will reduce the space between the peaks and troughs produced during mowing thereby producing a more uniform surface.  A cylinder mower with an 8-11 blade cylinder should be the equipment of choice for maintaining high quality ornamental lawns dominated by fine grass species (LandscaperPro Seed Mix : Finesse).  Rotary machines have a sharpened horizontal rotatory blade and are more appropriate for coarser grass varieties and higher cutting heights compared with the cylinder machines (LandscaperPro Seed Mix: Performance, Sun & Shade and Supreme).  The quality of cut is not as pleasing, thereby impacting on presentation, but they do mulch the clippings produced and the suction created by the blade helps maintain on upright growth habit and will remove debris from the base of the turf.

Both cylinder and rotary units are available in a variety of sizes from pedestrian through triplex and gang units.  The choice of machine will primarily be dictated by the size and shape of the area to be mown. Regardless of the choice you make it is imperative that the sharpness of the mower blades is maintained.  Sharp blades will produce a clean cut to give an increased level of boldness and longevity to any striping as well as maintaining a better colour thereby optimising presentation.  Blunt blades will create a rough edge which will impact on colour and presentation but will also increase the grass plants’ vulnerability to disease infections.

Set up your machine for the site

Pay careful consideration  to each mowing operation in particular the set-up of the machine in relation to the characteristics of the site.  If not,  easily avoided problems may arise, these include: , th: ‘scalping’ due to an inappropriate height of cut for the contours of the ground; ‘chewing’ as a consequence of blunt blades or poor set-up; ‘ribbing’ because the grass is too long for the height of cut;  uneven cutting where different heights of cut are produced at each end of the cutting reel due to a damaged bottom blade; and ‘washboarding’ (surface undulations) may also build up over time if an area is continuously mown in the same direction.

Summary

Frequent and correct mowing is critical to achieve the best quality lawn.  Focus on getting the height of cut correct for the grass type,  the frequency correct for the strength of growth and make sure your mower is set up properly.