Frost is essentially frozen dew. Ice crystals visible on the outside of the
plant can also form on the inside of grass blades. The grass plant, normally
resilient to footsteps or cart traffic, becomes brittle and fragile when ice
crystals form. Under the pressure of traffic, ice crystals puncture living
plant tissues and rupture plant cells. Damage will not appear right away, but
it will show up in footsteps and tire tracks the following days as the plant is
unable to repair itself and begins to die. Frost damage can occur on any
turfgrass mowed at any height but it is amplified when the plant is mowed low,
as on a putting green. In a best-case scenario, damage will be limited to leaf
blades only, which will eventually disappear once active turf growth resumes.
However, if the plant crown, or growing point of the plant, is compromised,
damage will be more severe and recovery could take months.
Keep in mind, a foursome typically takes several hundred footsteps on each
green, so even allowing just a few groups to play when frost is present can be
very damaging to the greens, and the rest of the golf course for that matter.
It is not completely understood when frost will cause damage, so the decision
to keep traffic off the golf course must be made conservatively to protect the
condition of the course. For this reason, golf facilities are wise to close the
course to play or delay starting times until frost has completely melted.