Iowa State University Horticulture and Home Pest News  Summer
Care of Lawns  This article was published originally on 6/9/1995
Sound mowing practices are necessary for a good quality lawn.
This is especially true during the summer months. Improper
mowing during hot, dry weather may seriously damage the turf.
Mow Kentucky bluegrass lawns at a height of 3 to 3 1/2 inches
during the summer months. During cool weather in spring and
fall, bluegrass lawns should be mowed at a height of 2 to 2 1/2
inches. The additional leaf area during summer shades and cools
the crowns of the turfgrass plants. Extremely high temperatures
at crown level can kill turfgrass.  When mowing the lawn never
remove more than one-third of the total leaf area at any one
time. A lawn mowed at a height of 3 inches should be cut when it
reaches a height of 4 1/2 inches. Removing more than one-third
of the leaf area weakens the turfgrass and reduces its capacity
to withstand additional environmental stresses. Weakened turf is
also more likely t