Grass - What’s too short or too tall?

Our lawns are the eyes into the souls of our homes…or at least, that what it seems like sometimes.  We love our grass, and yet, we mistreat it by cutting it too much and dumping toxic chemicals on it all the time.  With the Yard Detox Challenge, I’m always being asked by homeowners about how long or short their grass really needs to be. Most people always have a sense of what's too short or too long, but rarely know if, for example, 1-inch is too short or 3-inches too long.  

Too Much, Too Little
It seems like a basic question, but when I talk with people about their grass, they typically aren’t sure what a 1-inch or 3-inch blade of grass looks like.  Just in terms of math, 3 inches is three times the height of 1 inch…that seems simple enough…but does 3 inches look bad?  If your yard were only cut to a 3-inch height, would it look like a jungle or an abandoned lot or a house in foreclosure? 

All lawnmowers have settings for different blade heights.  The setting you have your blade will determine just how tall or short your grass is.  To help illustrate how different settings makes your grass actually look, I recently took photos of my lawn to show you. 

The above photo gives you the bird’s eye view of how different settings actually look.  There are four different lengths of grass in the image.  The strip labeled A was cut at the 1 ¼”setting on my lawnmower.  The strip labeled B is at 3 ¼” setting, and the strip labeled C is right in the middle of those two settings.  The area of grass not labeled is about 7 to 8 inches tall.   So the first question is, which do you like most?  Different people will like different lengthens.  

The image below shows the same strips but from the opposite direction.  

Here's a couple of close-ups to show you just how different the heights of grass really are.

The first close-up is of 1 ¼” grass beside a 3 ¼” cut.  The 1 ¼” inch setting is a favorite among many landscapers in my neighborhood.  It’s way, way too short.  You damage the grass by cutting it this short and create the conditions where chemicals and artificial fertilizers are necessary to keep your lawn looking healthy (even though it's not).  You can also see how the 1 ¼” grass looks yellow compared to the taller 3 ¼” grass.  At 3 ¼” inches, the grass still has a nice green hue and looks full where the 1 ¼” grass looks like its dying and needs rescuing. 

The second close-up shows how 8 inch grass looks beside a 3 ¼” cut.  At 8 inches, the grass is at its maximum height where it looks ok for a front yard.  Letting the grass grow to 7 or 8 inches gives it time to recover and reverses any of the negative impacts of years of mistreatment.   

The Backyard
In my backyard, I’ve really let my grass grow tall.  I reseeded the entire backyard last year, and I want to give it time early this season to get deep roots and reseed naturally.  I mowed two different settings with the grass.  In the image below, I’ve labeled the setting height.

I think this really gets to the heart of the issue of cutting your grass too short.  The discoloration of the 1 ¼” setting is really present, and it makes the grass look unhealthy.  At 3 ¼” setting, the grass still looks green and healthy.  The grass around the two strips is probably about 12 inches high.  At 12 inches high, the grass is probably a little too tall, but for a backyard it’s not horrible.  I also keep it nice and trimmed throughout the rest of the growing season.  There’s plenty of ecological value to letting grass grow taller too.  It will filter rainwater better, provides habitat to bees and other beneficial insects and enriches the soil.  From a maintenance perspective, allowing the grass to grow tall once or twice a season will mean I’ll probably not have to water it at all…not even during the hottest days of July or August.  And without watering it, it will stay green and lush.  I think that’s a pretty nice result for not cutting it too much. 

Growing Back
When you mow at a higher setting (say at 3 ¼”), you can still wait two weeks to mow it again without it starting to look unkempt.  If you wait three weeks, it’ll start to look a little out of hand.  Even so, cutting your grass every two weeks mean you save on water and eliminate the need for fertilizers and pesticides.  Less chemicals equals healthier grass, plus your soil will get healthier too.  Healthier soil means even healthier grass…and you guessed it, even healthier grass equals even healthier soil.  You will see a huge improvement in how your grass looks throughout the Spring and Summer even when it's hot and dry.  Taking the Yard Detox Challenge sets your yard on a cyclical path for a more and more sustainable approach to lawn care. You save money if you have a lawn care service.  If you cut your own grass, you save time…which is money in it’s own way.