Mowing Height Table    Best Mowing Practice    Affects of Mowing

The Art of Mowing

Mowing is the most important factor in the health, growth, and fullness of your lawn. Close mowing weakens turf significantly.  Mowing and controlling growth within an optimum height range will significantly and naturally enhance your lawn.  Your mowing practice can therefore be either the most beneficial or the most harmful treatment for your lawn.  Mowing should be viewed as a lawn treatment in much the same way as fertilizing, aerating, overseeding, or applying lime.   If you view mowing as a treatment, it is certainly the most repetitious treatment performed.  Sense you have to mow your lawn anyway, its just good common sense to follow mowing guidelines that will benefit the growth and development of your lawn the most.

Properly done, mowing can have a significant impact by simply favoring the growth of grass over weeds. Understanding the importance of a strategic mowing program and implementing it, will turn this regular household chore into your most powerful lawn care ally.

Generally you will leave the grass at a higher height as determined by the type of grass and season of year. This will mean that sometimes you may have to cut twice per week, while at other times you will only mow twice a month. You should never cut your grass below a height specific to the species of grass and season.  You should never cut more than 1/3 of its height.

Mowing your grass the same day every week without considering its height is not what nature requires for the best maintenance and care of your lawn.

How does mowing affect the growth of grass?

Close mowing weakens turf by removing vital leaf surface.  Mowing too close forces the grass to desperately use its available food supply just to re-deploy its leaves as opposed to thickening. 

By leaving grass longer and not cutting it too low the following benefits are realized:

1) More food is manufactured by the leaves and will be available for thickening. Grass thrives on food produced in its leaves more so than what is drawn up from the root system.  Taller grass is healthier and well nourished and more capable of thickening with new shoots.

2) Longer top growth promotes longer and deeper root growth.  Nutrients and moisture reside in the depths of the soil.  When you cut more than 40% of the leaf surface, the roots stop growing all together. The closer you cut, the longer it takes for the roots to begin growing again.

3) Longer leaf growth shields the sunlight from weed seeds that need light to germinate and grow.  Grass and weeds compete in a quiet war for the sun.  Sun is food.  Food is strength. Shade is weakness, disease, and death.  A healthy stand of grass will shade and kill weeds naturally if it is tall enough.   A tall, dense grass also helps to hold moisture.

4) Proper mowing practice leads to the thickening of grass plants. Grass naturally wants to reproduce itself.  Necessary and regular cutting inhibits propagation by seed production but does encourage plant propagation by sprouting new shoots, tillering.  This leads to the thickening of grass.  When grass thickens there simply is less room for the weeds to grow.  Back to Top of Page

Best Mowing Practices

1) Grass is better cut at a higher height more often.  This will mean that during periods of greatest grass growth rate, you will need to mow more than once a week.

2) The most beneficial mowing heights vary by grass species.  The mower deck should be raised in hot weather or shade, and lowered for the last mow of the year.

Here are the best mowing heights, in inches, by species as recommended by the Maryland Cooperative Extension (Home & Garden Mimeo #HG 101).

3) Never cut more than a 1/3 of the height in a mowing treatment.  The following table suggests the height range within which to maintain your grass.  Cut the grass when it is no higher than the upper height of each range.  Set your blades to cut no lower than the lower height of the range.

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Mark a wooden stake at your turf's desired cut height, the lower height of the control range, and then another mark at the upper height of the control range.  This will be your visual guide to check your lawn height and to know when it will be the best time to mow.   Cutting too much off at one time or cutting it too low will damage your lawn, severely limit its growth, and give advantage to weeds.

If you have a lawn cutting service they will probably want to cut on a time schedule convenient to the operation of their business.  This schedule may or may not coincide with a well thought out mowing program that considers the most beneficial control heights of the grass, most recent weather related growth rate, or what is most beneficial for the longer term growth and development of your lawn.

5) Keep your mower blades sharp.  The cleaner the cut, the more the grass will positively respond to this treatment.  On a golf course, blades are sharpened once a day. The homeowner should sharpen his blades at least once a month.  Buy an extra set of blades and have them sharpened and ready to install.  Back to Top of Page