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Why Mowing Too Short is
Terrible for Your Lawn

Published on 27th May 2022 by Mitchell

One of the most popular urban myths circulating among home owners is the idea that setting your lawn mower low is the way to go.  This is often done in attempt to slow down growth and reduce the frequency at which it needs to be cut.  I’ve got some bad news for you.  This couldn’t be more wrong.

In this blog post I’ll not only be pointing out the harm you can do to your lawns by mowing them too short, I’ll also be drawing on my experience of having mown thousands of lawns in the North Island of New Zealand to provide you with some actionable tips that you can use to move closer to your goal of having a thick, lush, deep green lawn.

The damage you can do when cutting too low.

Mowing your lawn too short does a few things which negatively impact it’s long term health:

It promotes blade growth at the expense of the roots.

Grass is just like any other plant in the sense it needs to photosynthesize sunlight and drink plenty of water to thrive.  Cutting too much off the top forces your lawn to divert all of it’s energy into regrowing the blades as it’s ability to convert sunlight into usable energy has now been compromised.  This comes at the expense of growing a deeper root system which is imperative for a thick lawn.

If you wanted to cut it shorter to make it grow back slower, I’m afraid the blades are going to grow back much quicker, and with a very brittle, uneven look!

It increases the risk of scorching during  the hotter months.

When a lawn is mowed too low the soil and roots are exposed to direct sunlight.  Ideally the grass blades would provide shade to the soil and to the roots to not only keep them cool, but also to increase water retention when either you or Mother Nature get around to giving it a good soaking. 

Our climate can be very arid, particularly in the summer, and if you drive around your neighborhood and take note of which lawns are sorry and brown brown vs. which ones which are lush and green, I guarantee you the most discernable difference will be in the length of the grass.

It invites weeds and foreign grasses.

Elaborating on the points above:  when a lawn gets weak and brittle in the heat, and when it’s unable to establish a thick root system, there is that much more space in the lawn for weeds to germinate and establish themselves.  They are also able to get the sunlight they need in order to take off since the grass isn’t long enough to shade the soil.

If you’re lawn happens to be comprised of a turf grass and you let a creeping grass like Kikuyu get a foothold in it (I know, I hate the stuff too), it will need to be dealt with immediately before it aggressively takes over the entire lawn.  Why not save yourself the trouble of having to spray weeds and foreign grasses altogether?  Afterall, prevention of a problem is far more effective than treatment!

A longer lawn is a healthier lawn.

One of our client's lush green lawns in Papamoa

To sum it all up, keeping your lawn at a reasonable length in conjunction with a consistent mowing/watering schedule is always going to yield the best results.  Here are a few pointers you can use to improve the health of your lawn and avoid the temptation to cut it too short:

  • Use an online chart to figure out your grass type and ideal length.  (we’ll be releasing our own one and linking it here in the near future)
  • Never cut more than 1/3rd of the blade off your lawn with each mow.
  • If the lawn is growing faster during Autumn and Spring, mow it (or ask your service provider to mow it) more often.
  • Adjust the cutting height of your lawn based on the season – leave it higher in the summer for increased shade/water retention.