Mowing is the most basic and frequently performed lawn care practice. Proper
mowing is essential in the maintenance of quality turf and can radically impact the
effectiveness of the fertility programs we provide.
Grass, like all other plants, relies on photosynthesis to survive and grow. Close mowing
reduces the amount of leaf area available for photosynthesis, limiting the grass’s ability to
produce energy. As cutting height drops, lawns become less tolerant of environmental
stressors and more prone to invasion by weeds and insects. Cutting too short will also
stunt root development resulting in a shallow root system.
Although a closely cut lawn can be maintained successfully, it will require more frequent
watering and fertilization to compensate. At Mainely Grass, we recommend mowing to 4
inches or the highest level that meets the aesthetic and intended use of your lawn.
Many of us are used to cutting our lawns on a set schedule. That works out great for our calendars
(or our children’s chores!), but it is not how grass grows throughout the changing seasons. It grows
most vigorously in the spring when temperatures are warming but not yet hot, then slows
during the heat of the summer, and picks back up in the early fall as it prepares for
winter. How fast your lawn is growing should ideally determine how frequently it gets
mowed. In order to avoid stressing the turf, no more than one-third of the grass shoot should be
cut at any one time–this is commonly referred to as the “1⁄3 Rule”. For example, if a
lawn is being mown to 4 inches (like we recommend), it should not be allowed to grow
higher than 6 inches before it is mown again.
Cutting off more than one-third of the shoot in one mowing puts severe stress on the
grass. Somewhat counterintuitively, your grass will respond by re-growing its shoots
faster while sacrificing root growth and depleting its energy stores. Mowing high, and
following the 1⁄3 Rule will help keep your turf healthy and hardy, and keep you from
mowing all the time!
Unless an excessive amount of clippings remain on the lawn after a cut (because
of infrequent mowing, for example), there is no need to remove clippings by bagging or
raking. In fact, clippings are a valuable source of nutrients and organic matter. Mulching
your clippings will recycle up to 25% of the nitrogen in your grass and help to improve the
structure of your soil and in turn, the health of your turf (especially if your soil is sandy or low in organic matter).
Contrary to popular belief, mulching clippings does not contribute to increased thatch
formation. Clippings are primarily composed of easily degradable compounds which
break down rapidly and do not accumulate.
If the lawn is mown when wet, clippings may clump together and make removal–or even a
“double cut” to further mulch the cut grass–necessary. Mowing when the lawn is dry will
help to prevent clumping, but please don’t abandon the 1⁄3 Rule just because the grass is wet!
Mowing Equipment Maintenance & Patterns
The most important thing to remember for mower maintenance is to keep the blades as
sharp as possible. Dull blades will tear the grass rather than sheer it, resulting in
unnecessary injury to your turf. This tearing opens up more surface area which can allow the disease to enter and also
weakens the grass making it more susceptible to insect attack. It will also generally brown the tips of your grass
making your lawn look somewhat burnt and unappealing.
Some pros can do amazing things with mowing patterns, and if you are one of them,
enjoy! If that isn’t you, just remember to vary the direction you mow to avoid creating
horizontal growth (called grain) over time. The easiest way to do this is to mow at right
angles on alternate mowings, but any variability will do.