First frosts: How does frost affect your lawn?

First frosts: How does frost affect your lawn?
First frosts: How does frost affect your lawn?

There’s something very picturesque about a lawn with lots of little white tips and a rising mist, but it may not be the most welcome sight if you’ve recently sown new seed or have a recently established lawn. Frost on your lawn’s surface will not do much damage on its own but if you walk on, crush or flatten the blades then you could badly damage it.

One frosty morning in a week shouldn’t do too much damage to your lawn. However, if it becomes a regular occurrence you may need to consider the lasting effect it may have on your grass. The actual frost does not kill your grass but you will damage it if you or your pets walk on it.

How does frost form?

Frost is essentially water vapour, that freezes when an outside surface cools past ‘the dew point’. The dew point is when the water vapour (gas) turns into a liquid because it is so cold, and therefore forms on the grass and freezes the blades. This happens overnight as air temperatures drop. You will then notice that most frost will disappear mid-morning as temperatures become milder and your grass begins to thaw.

What damage can frost do to my lawn?

Frost freezes your grass blades and makes them rigid and brittle. Much of grasses’ ability to ‘bounce back’ from wear and tear is its flexible blades. So when this ability is compromised, it can make it more vulnerable to damage.

How can I stop frost from damaging my lawn?

Pre-frost preventative measures:

Apply a fertiliser

Just like us, grass has an immune system that needs to be built up over time. You can aid this by applying an autumn / winter fertiliser that is high in potassium. This will help to strengthen your grass's resilience to disease and frost.

It's best to apply our fertiliser anytime from August to October - this gives your lawn the ultimate protection from winter disease and frost during the cold winter months.

When a lawn is left unfed, it will not have the nutrients it needs to fight off winter-borne diseases and may succumb to them. If you have a relatively young lawn (sown this summer or this year) then applying fertiliser this autumn / winter is recommended.

Don’t mow too short

When planning your last mow of the season make sure to mow a little higher than your usual setting. You also need to make sure that your mower blades are sharp. Be aware that cutting on a low setting with a blunt blade can sever the cells within your grass, which stops them from being able to repair and grow again.

Post-frost actions:

Don’t walk on the lawn

The most obvious way to stop frost from damaging your lawn is not to add to the problem. This means staying off the lawn when there is frost – and this goes for your pets too! Grass blades that are walked on when frozen can split and break. And when your lawn wakes up again in spring can appear yellowed / brown or dead.

Repair in early spring

If your lawn does emerge damaged in spring, you can of course repair it – but to avoid this happening year on year, using the above advice will help cut out this extra work!

We also have some quick tips to help you make sure your garden is ready for winter and we have a guide on how to revive your lawn after winter.