Frost Green Policy
Cannington Golf course has a policy of "Frost Green" use during a white frost and when the greens remain frozen. These are checked every half hour with a probe during the thaw, and the play is returned to the main greens after a satisfactory inspection by the greenkeepers.
During a white frost, footprints, trolley wheels and vehicle tyres crush the frozen grass leaves leaving superficial blackened scorch marks. To avoid this marking up on or near the green, the frost greens are placed away from the main greens.
Clumps of frozen grass from golf shoes would also be deposited all over the green. This debris makes putting difficult for others and would need clearing off manually before it re-freezes (as mowing is less frequent in winter).
What is a frost green?
These temporary greens (defined by a circle of blue dots) are maintained all year, and in autumn/winter are mown to the same height as the main greens. Every effort is made to ensure a reasonable, smooth putting surface, although a larger 6 inch hole cup is provided, allowing for inconsistent surfaces. When not in use, temporary greens should be considered as areas of "ground under repair", thus avoiding divot damage.
But why when the white frost has gone?
Golf greens have much lower grass "height of cut" and so less insulation from the cold. Also, sand based greens (being well drained) contain less moisture. This combination allows them to freeze more deeply than the rest of the golf course and so take longer to thaw. Each progressive frost without a thaw freezes them deeper.
Most physical damage is done to the fine turf during the period of thaw, when the greens are warming in the sun from the surface down. The white frost is gone but ice still remains in the root zone. The surface becomes too soft and wet but just below it can still be frozen, when movement of the turf by foot or mower traffic will damage roots and compact the green.
If play remains on a green for days when frozen, the wear will be concentrated around the pin position which cannot be moved, resulting in long term winter thinning of the grass.
When the white frost has gone, the greenkeeper will check the greens with a probe every half hour, feeling for a full thaw; only then returning the flag to the main green.
We are aware that playing on "frost greens" and winter tee positions are not the best way to enjoy your golf, but consideration is appreciated as we strive to protect the course during cold or wet winter periods, for the long term benefit of the course in the main season.