Don't Scalp Your Lawn

(First published at Hardisonink.com) 

        It was the first to greet me when I arrived:  my grass with two weeks of uncontrolled growth.  We’d obviously gotten plenty of rain at home during my two-week vacation.  My first instinct was to hop onto my mower and chop it all down.  Fortunately, I knew from the University of Florida IFAS Publication, “Mowing Your Florida Lawn,” that cutting off more than one-third of the blade length at a time can cause severe stress to the plant.  So, I adjusted the cutting height of my mower first, even though my yard might look a little ragged before I’m able to cut the grass shorter.  

        Knowing when and how short to mow your grass is very important when trying to maintain a good quality lawn.   “Scalping,” or removing too much grass at one time, can cause long-term damage, leaving the grass vulnerable to insects, disease, and drought.  Taller grass will develop deeper roots and, therefore, be able to better tolerate drought, heat, traffic, insects, diseases, poor soil, and other adverse conditions.  

        The best cutting height depends upon the species of grass you have.  A grass that grows more horizontally is usually cut shorter than those that grow more upright.  Also, grasses with narrow blades can generally be cut shorter than those with wide blades.  Mow often enough so that no more than one-third of the blade height is removed per mowing.  If you know the species of grass in your lawn, then you can use the following chart to determine how often and how short it should be cut.

Turfgrass Species	Optimal Mowing Height (inches)	Mowing Frequency (days)
Bahiagrass	3.0 – 4.0	7 – 17
Bermudagrass	0.5 – 1.5	3 – 5
Carpetgrass	1.5 – 2.0	10 – 14
Centipedegrass	1.5 – 2.0	10 – 14
Seashore Paspalum	1.0 – 2.0	5 – 10
St. Augustinegrass	2.5 – 4.0*	5 – 14
Zoysiagrass	1.0 – 3.0	10 - 14
*Dwarf cultivars of St. Augustinegrass (Seville, Captiva, Delmar) are the only cultivars of this species that should be mowed at 2.5”.  Other cultivars should be mowed at 3.5-4”.

        Leaving grass clippings on the lawn will reduce yard waste and help recycle nutrients to the soil.  If the clippings clump they can be raked or blown to distribute them more evenly.

        The best ways to have a great lawn are to fertilize appropriately, mow at the highest possible height, and irrigate on an “as-needed” basis.  

        The above information comes from the University of Florida IFAS publication “Mowing Your Florida Lawn,” by L.E. Trenholm, J.B. Unruh, and J.L. Cisar, and can be found online at http://edis.ifas.ufl.edu/lh028 .  Additional ways to care for your lawn can be found at the web site, “Your Florida Lawn,” http://hort.ifas.ufl.edu/yourfloridalawn/ .