Improper mowing causes more problems on lawns than any other
maintenance practice. Most lawns are mowed too short, not often
enough, and/or with a dull mower blade.
Mowing height depends on the grass species. Kentucky bluegrass,
or any mix containing Kentucky bluegrass, should be mowed at
2.5 to 3.5 inches; perennial ryegrass and fine fescue should
be mowed at 2.5 to 3.5 inches; Southern varieties of Tall Turf
and Kentucky 31 at 3.0 to 4.0 inches; and zoysia at 1.0 inch.
Mowing below the optimum height restricts root growth and increases
susceptibility to damage from insects, disease, drought, and
traffic. Low mowing also favors weed infestations. Shaded areas
should be mowed 0.5 to 1.0 inch higher than optimum.
Mowing frequency depends on how fast the grass is growing.
Some lawns may need mowing twice a week during spring and fall
and only once every 2 weeks during summer. Mow frequently enough
so as not to remove more than 1/3 of the leaf blade a single
mowing. For instance, if you are mowing at 3 inches, mow when
the grass reaches 4 inches. If the grass has grown too tall,
raise the mowing height and gradually lower it back to the original
height over a few mowings. Avoid mowing during midday when temperatures
are above 90o and the soil is dry because you may damage the
turf.If you must mow during a hot and dry period, wait until
temperatures moderate in the early morning or late evening.