Robot Lawn Mowers for Large Properties: 1, 2, 5 and 20+ Acres

Makers publish a coverage figure for each robot mower, and that figure is where every large-property plan starts. It is also where plans go wrong. The USGA reports that new owners often find the machines cover less acreage than the manufacturer states, and that reworking mowing zones and schedules recovers part of the gap. So the right way to read a coverage number is as a ceiling for open, flat turf mowed often, with your own slopes, obstacles and mowing window taking something off it. Source

The second thing to read is the quality assumption behind the number. Husqvarna US publishes two figures for the same CEORA: up to about 6 acres at professional sports quality with round-the-clock care, and up to about 18 acres at regular quality mowed twice a week. Same machine, three times the acreage, because the turf is cut less often. Decide what the property has to look like before you count units. Source

Slope is the first subtraction. Husqvarna lists a maximum slope of 20% inside the work area for the CEORA 544 EPOS, ECHO lists a 45% maximum standard slope for the TM-2050 and NALP reports 40% for the Kress Voyager. Any zone steeper than the machine’s limit stays with the crew or goes to a different machine, and that zone’s acres come out of the robot’s total. Source

Sky view is the second. Satellite-guided mowers need a clear fix; MowScout says heavy tree canopy and tall building shadow degrade the RTK fix. A 20 acre campus that is half under oaks is a 10 acre robot site. Obstacles are the third: every bed, path, bench and tree ring is a boundary to map, and a mower that stops and asks for help on what it cannot clear spends less of the day cutting. Source

The mowing window is the last. A golf course that wants its fairways done before the first tee time has a few hours a night; a solar site may have all day. The same acreage needs more units in a short window. Golf Course Industry reported four reel mowers finishing 60 acres in about four hours a night, which is why fairway programs are fleets. Source

We walk the property and split it into zones by turf, slope, sky view and the hours it can be mowed. Each zone gets the machine class that fits it, and the published coverage figures get discounted for what we saw. The quote lists the unit count, a 3-year lease with a $1 buyout, mapping and setup, crew training and service as separate lines, so a board can see what each acre of robot mowing costs before committing. A site can start with one zone and grow.