Introduction
Rolling can be a much overused operation and should be used judiciously by both the turf manager and lawn owner. Even without using a purpose built roller, regular light rolling usually takes place each time the grass is cut when a cylinder mower is used, or a rotary with a rear roller, and any additional rolling is only carried out to put the finishing touches to a sward, which may not have been achieved with the mower.
What does it do?
It can be used to firm, that is consolidate, but not to compact the turf surface and is especially useful in firming the soil after any surface heave has occurred during the winter or spring.
Great care needs to be undertaken to ensure that excessive use is not made of the roller, nor that it is used when the soil is too moist, otherwise undesirable compaction will result.
Fine turf
Rolling is sometimes carried out prior to competitions in fine turf sports such as golf and bowls to improve the speed and evenness of roll for the ball or bowl.
A useful roller for putting the finishing touches to a golf or bowling green is a tandem type roller which has the benefit, unlike the garden type roller, of riding over low areas and gradually 'squeezing' the higher spots into those low areas.
A sit on turf iron is similar to the tandem type, but is mechanised and has a combined weight, with an average sized person as the operative, of some 300 kg: These are mainly used on golf greens.
For the more discerning lawn owner, the purchase of a sarel spiked roller would combine the benefits of surface aeration with the production of a firm, even surface.
Cricket / Tennis
Sports surfaces which require regular use of the roller include cricket pitches and tennis courts. These require surfaces which are very solid and produce a lot of bounce due to the content of clay within the rootzone, which is 'squeezed' together to form a soil that is tightly packed.
Rolling method
Rolling an area that has an unsuitable depth of thatch will result in the turf springing back up following the passage of the roller - this is due to the sponginess of the thatch. Little surface firming will result, only subsurface consolidation or compaction.
As with mowing, it is essential to regularly vary the direction of any rolling, to provide as even an area as possible and to reduce the potential for 'ridging'.
If in doubt, it is probably best not to roll on most turf areas with cricket and tennis being the exception.