Winterkill is a general term used to describe the vegetation death that can occur during the cold winter months. Here is Australia, we are fortunate to experience fairly temperate and mild winters with only the highlands of NSW and Victorian amongst select other areas experiencing true winter temperatures.
That being said, here in South East Queensland we can still experience some extreme (for the region) temperatures in both summer and winter. Although the August South-Westerlys give us the most grief, from mid June through to the end of July, frosts can be a green keepers worst enemy.
The combination of sunny days and cool clear nights with low temperatures like this weeks predicted forecasts means you need to be on frost watch. The mosts susceptible turf species to frosts are couch’s such as Winter Green, Aussie Blue and Queensland Blue Couch. The newer premium turf species like Sir Walter, Palmetto and Empire Zoysia have a much better frost tolerance and the few frosts we have will hardly worry them!
Freezing temperatures rob plants of their moisture to form a frost layer.
Try to stay off a frosted lawn, if you walk on the lawn while the blades are frozen you could damage your turf. If the ground is above freezing and there’s no frost, you’re in the clear. If your lawn has been frosted you can speed up the thawing process by hand watering your lawn for 30-60 seconds. The addition of a little “warmer” water should be enough to melt whatever frost has settled.
If you didn’t catch the frost in time you will notice the blades of your grass go a dark purple/black colour after a few days. Try to resist the urge of mowing until new grass has shot through which might be a week or so.
It is also best practice through the winter to lift your mowers cutting height to maximise photosynthesis during the shorter days on the larger grass blade surface area.