Unlike a standard rotary lawn mower, a flail mower cuts with a series of short knives mounted on a rotating shaft. That configuration allows the flail mower to cut easily through thick grass, weeds, vines and trees up to 4 inches in diameter, depending on the model, according to the Grounds Maintenance website. Flail mowers typically are mounted on tractors and used to mow large fields or maintain highway medians and berms. Smaller, self-propelled flail mower models are available, however, and are generally adequate for most homeowners.
Strength and Operation
The primary advantage of flail mowers is that they make it much easier to clear overgrown areas and maintain places where tough, thick weeds grow. Flail mowers handle wet plant materials much better than rotary mowers as well and are less likely to clog with cut vegetation. Because the cutting knives of flail mowers are mounted in a way that allows them to swing freely, flail mowers are much less likely than rotary mowers to throw stones and other debris. A flail blade that hits a rock or other solid material simply folds back from the object rather than lifting and throwing it.