MOWING

PART 2- CUTTING HEIGHT

Introduction

CUTTING HEIGHT

There is no single “ideal” cutting height for turfgrass. The choice of cutting height is influenced by the type of grass, the climate of the area and the game that is going to be played.

Cutting height is defined as the distance above the soil surface at which the turf is mowed. The bench setting is the height at which the cutting edge or bed knife is set above a level surface. It is the height generally referred to in the cutting height recommendations for various turfgrass species and cultivars. The effective cutting height is the actual height above the soil surface at which the turf is being cut. This height may vary from the bench setting because of the varying thickness of thatch and floatation of the cutting unit.

The primary criteria utilized in selecting the cutting height for a given turf are:
A.Physiological condition of the turf;
B.The purpose for which the turf is to be utilized; and
C.Growing habit of the turfgrass involved.

A.Physiological, development and growth effects.

As the cutting height is lowered within the tolerance range, low growing turfs exhibit the following responses;

1. Decreased carbohydrates synthesis and storage.
2. Increased shoot growth per unit area.
3. Increased shoot density.
4. Decreased leaf width.
5. The increased succulence of shoot tissues.
6. Increased quantity of chlorophyll per unit area.
7. Decreased root growth rate and total root production.
8. Decreased rhizomes growth.

B.Influence of use requirements.

The cutting height is dictated by the purpose for which the turf is maintained. For example, a very close cutting height of 6mm, is required on a bowling green to provide the desired quality of surface necessary for good playability. This includes a smooth, uniform, dense, resilient playing surface free of excessive thatch. In sports that involve running, such as soccer, a close cutting height is desired to achieve maximum running speed. The height of the cut can also affect the degree of bounce, ball roll and distance. It’s a balance between what the game need and turf health.

C.Turfgrass species and cultivars.

Turfgrass species vary greatly in tolerance to cutting height. The cutting height tolerance of a given species or cultivar is a function of the growth habit including both stem and leaf growth characteristics. Stem growth involves the:

a.Erect versus Horizontal direction of growth or an intergradation between the two.

b.Location of the crown apical meristem in relation to the effective cutting height.

Prostrate low growing turfgrass such as Bermuda grass tolerates a much shorter cutting height than erect growing turfgrass.

PREFERED MOWING HEIGHT – WARM-SEASON TURFGRASS

The turf becomes weak and less vigorous if the cutting height is lower than normally tolerated by a given species or cultivar. The more erect growing species are eventually eliminated through continued close, frequent mowing. Mowing too high causes as many problems with certain turfgrass species as cutting too close. The prostrate growing species such as Bermuda grass must be mowed close, otherwise, excessive thatch accumulation and puffiness occur.

Media Department; The RS Group.