What’ll it be: rotary or reel? As its name suggests, a rotary mower cuts with a spinning blade. A reel mower functions with a reel and a bed knife, with a slicing action akin to shears.

“The reel mower is going to be a cleaner cut,” he said. “But that doesn’t have that big of an effect on grass. It takes a really dull rotary mower to make much of a difference. A sharp ...