How Fast Can You Mow with a Zero-Turn Mower?

Correct Speed

• A zero-turn mower does not come with specific information about how fast it should be driven while mowing, but two signs that it is driven too quickly are streaking and scalping. Streaking is when the mower leaves strips of grass uncut, and scalping is when the mower deck jostles and cuts grass so close to the ground that it leaves bare or thin spots. Mowing at a slower rate of speed can prevent streaking and scalping.

Non-Mulching Speed

• A standard zero-turn mowing deck side-discharges grass clippings, spreading them evenly over the lawn as it makes each pass. One zero-turn model has a top ground speed of 7 mph when moving forward and 5 mph in reverse. Cutting, or mowing, speed depends on grass' height and thickness. The zero-turn model's operator’s manual advises not cutting off more than 1 inch of grass in one pass and experimenting until you find the ground speed at which the engine does not bog down. If you need to cut more than 1 inch from grass, then make more than one pass over the grass. If the machine has a manual transmission, third gear is the highest gear to use while mowing.

Mulching Speed

• Mulching cuts grass several times under the mower deck before discharging it onto the lawn. The process yields smaller, less noticeable grass clippings than non-mulched clippings. It requires a lot of horsepower and is achieved by running the mower at full throttle and one-half the ground speed used when not mulching the clippings. If you find that 6 mph is the best speed for non-mulching mowing, then mulch at 3.5 or fewer mph. Set the zero-turn mower deck so that not more than 3/4 inch is removed from grass blades in one pass. Experiment until you find the right mixture of ground speed and mower deck height. Speed also depends on climate, and the grass must be dry to mulch properly.

Slope Speed

• Do not use a zero-turn mower on a slope greater than 15 degrees. At least one zero-turn mower manufacturer recommends mowing a slope from side to side, rather than up and down, with its zero-turn mower. Also when cutting grass on a slope, mow at a slower speed than on level ground, mow at a rate that you will not need to speed up or slow down and mow when grass is dry. Mow at a speed that does not cause the mower to bounce around and lose traction. Turn around on a slope uphill and at a slower speed than while mowing.