We know it needs to be very cold indeed to freeze sea water because it is salty. The more salt that is in there, the colder the freezing point is.
The cells that make up grass leaves are full of salty water. Different types of salt to sea water but the effect is the same. The cells of grass leaves won’t freeze in anything but the coldest of temperatures, certainly well below zero.
So what is frost? The white stuff is the water vapour in the air that freezes as it condenses onto the surface of the grass. If it wasn’t frozen, you’d call it dew. The grass therefore gets a coating of solid ice. Inside, however, it’s still liquid and busy being alive.
If you walk on a frosted grass surface you will damage the grass by shearing the leaves. You will break their frozen outer coating and in so doing inevitably damage the softer material within. That’s why turf that’s been walked on often looks like it has been bruised at each step.
If you cover your turf up before the moisture in the air condenses onto the surface of the grass you’ll avoid these problems.
There won’t be enough moisture laden air immediately above the grass to cause a layer of frozen water (dew turns to frost) to develop on the grass surface.
Frozen soil water
- The water in the soil will freeze if soil temperatures drop below zero. In order to prevent this from happening you need to address the following…
- How much water is in the soil? There are many factors that affect this including drainage, soil texture, soil structure and of course how much rain there may have been.
- Can you heat from below?
- Can you keep heat in by covering above?
Matchsaver won’t alter your soil structure or texture but it will allow you to control the amount of water arriving at the surface of your pitch. It will also allow you to keep more of the heat in, whether that’s come from an under soil heating system or from the sunshine and warmer daytime temperatures. Night time covering will retain heat and help prevent soil temperatures dropping below zero.
Tim Lodge, Agrostis,
Agronomy Consultant to Matchsaver