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Mowing for a healthy lawn

As the first few warm days of spring bring forth the promise of enjoying the outdoors for things like bike riding, hiking, camping and playing golf, it is also time to get ready to spend time on your property doing things like grilling, gardening, and lawn mowing.

Mowing falls into a large spectrum for people. Some look forward to it others hate it. However, no matter where you stand on lawn mowing, it is an important key to keeping a lawn healthy and beautiful and all the advantages that go with it. A nice lawn increases property value, helps cool the landscape and even the home, and provides a fun and comfortable place to enjoy the outdoors by walking right out the front or back door.

A properly mowed lawn is greener, stronger, and more durable than the exact same lawn being mowed with less diligence. The problem is good mowing practices means a great deal more than mowing when the lawn gets long.

What are the keys to success, beyond shortening the length of the grass blades, when mowing?

To better understand what other factors go into healthy mowing practices it is best to look at something personal: cutting hair and shaving.  Do you want a sharp razor when you shave? Would you prefer sharp scissors for a hair cut?  Sure, you can cut your hair or shave with dull implements, but the chances for uneven cuts, nicks, and missed spots raise as the dullness of the blades go up, so does the pain and recovery time.  Grass is the exact same way. A dull mower blade doesn’t cut the grass it rips it. Ripped grass is more prone to disease, drought stress, and insect damage. Why is this? Let’s start with the most obvious; ragged ends of grass blades cannot heal as fast, contributing to moisture loss. As moisture loss increases so does drought stress.

In addition to moisture loss, the frayed tips of grass blades make it far easier for fungal spores to find access into the tissue of the leaves. This makes the lawn more susceptible to diseases. Again, think of shaving. When you nick yourself, the cut has a chance of getting infected. If the shave was clean the nick never happens and there is no pathway for germs to enter.

Another easy crossover between a dull haircut and a dull lawn mowing is simple aesthetics. When a dull or unbalanced mower blade goes over the grass, some of it isn’t cut, but is instead ripped or even pushed out of the way. This leaves the lawn uneven and unappealing to look at, much like an uneven haircut. At the same time the tips of the grass cannot heal and turn brown. It is no different than leaving stubble from a dull razor.

What about the height of the lawn? At some point the lawn gets so tall mowing is a must, but is it really healthy to let a lawn get so long and out of control to begin with?

The truth is, lawns do have a good mowing height for both health and appearance. The ideal in the Front Range is between 2.5 and 3 inches from ground to top of the grass blade. The height allows
the lawn to shade the soil and cut down on evaporation from ground, while being low enough to not get trampled down. Once grass blades start to lay over, mowing becomes difficult and it is easier for insects and diseases to hang out in the pockets under the laying down grass. Furthermore, water has a harder time getting down to the soil since much of it sits on the mat of fallen over grass blades. Evaporation then happens quickly in our low humidity; so much of the water being applied never benefits the lawn if the grass is too long.

This leads up a very important question: when should a lawn be mowed?
Turf grass is no different than any other plant. It produces food through photosynthesis, taking sunlight, oxygen, ground nutrients, and water to produce growth. Photosynthesis is done where the grass gets the most sunlight. This is the greener parts of the blades of the grass. As long as the grass is being cut regularly, there is little to no loss of the grass’ ability to maintain this process. However, if a larger amount is removed, the leaf blade further down cannot handle the sunlight and the process stalls until it can. This weakens the grass. Because of this, it is recommend cutting to where a maximum of 1/3rd of the grass blade is removed at any one cutting, then giving the grass time to recover and grow some before mowing again. Because the optimum height is between 2.5 and 3 inches, the lawn should be mowed before it reaches a height of 4.5 inches.

Mowing patterns are also important. Mowing the lawn in the same direction and the same way each time causes the grass to always lean the same direction. By changing things up and mowing in different patterns, the glass blades cannot get used to a pattern and tend to stand straighter. This promotes better moisture penetration and airflow in and around the blades of grass. Both are aspects important to lawn health.

There is yet one more often forgotten reason for good mowing practices. A lush well mowed lawn can ward off insects that can do serious damage.

As part of understanding the link between good mowing and the lawns ability to fight off insect incursions, it might be good to understand a little bit more about many of pests that can attack a lawn.  Insects are not equal opportunity invaders. Much like any natural predator, bugs seek out easy places to live, feed and breed. This means insects more easily establish themselves on a weaker less cared for lawns. Many insects can find weak areas to get started in, then spread out to damage larger areas. Keeping a lawn well mowed discourages them and allows the lawn to naturally fight off predators. In the grand scheme of things, it is not much different than a fox going after two rabbits, one is healthy the other injured. The chance of the heathy one surviving is greatly increased.

With all this said here is an easy list to use when thinking about what is the best mowing practices.

  1. Keep the blade sharp
  2. Keep the blade and undercarriage of the mower clean.
  3. When sharpening the blade check balance (to do this put the center hole of the blade on a nail. If it hangs straight up and down, it is well balanced. If it leans then grinding a little bit off the back side can put the blade back in balance)
  4. Mow to a height of 2.5 to 3 inches in length
  5. Never remove more than 1/3rd of the length of the blade of grass at any one mowing. (mow before the grass gets to 4.5 inches.
  6. Change the pattern when mowing

Lawns can tell us when there is a problem, this includes mowing. If the tips are ragged or if the mowing leaves uneven spots, there is a problem. Take care of your lawn so you can enjoy it.