Robot Mowers on Clover and Micro Clover Lawns: What Works and What You Lose

Clover lawns are having a moment. Homeowners are sowing micro clover into their grass for a greener lawn with less fertilizer, and extension services in the Midwest and Northeast now publish guides to “bee lawns” that mix low-growing flowers into turf. At the same time, robot mowers are designed to trim a little every day, which is the opposite of what a flowering lawn wants.

The two can work together. It depends on which kind of clover lawn you’re after, and on setting the mower up differently from a plain grass lawn. This guide explains how. MowReview quotes no prices and hasn’t tested these mowers. How we research explains why.

First, decide what kind of clover lawn you want

What extension services say about clover

• It tolerates mowing. Purdue says white clover “tolerates close mowing” and spreads by creeping stems. A robot mower won’t kill it.
• It feeds the lawn. Clover adds nitrogen to the soil. The University of Maryland says micro clover “may reduce one nitrogen application per year,” and the University of Minnesota says white clover doesn’t need nitrogen fertilizer.
• It doesn’t like traffic. The University of Minnesota says white clover “has poor traffic tolerance,” and the University of Maine says clover “will crush more easily than turfgrass” and is not recommended for heavy-traffic areas.
• It’s slippery when wet. The University of Maine notes clover is “quite slippery when wet.”
• Micro clover has limits. The University of Maryland says micro clover has fewer flowers than Dutch white clover, “does not tolerate high heat and drought,” starts to die back when cool-season grass goes dormant in summer, and needs reseeding to persist. Most broadleaf herbicides kill it.
• The mix. An Extension answer citing Penn State and Maryland trials recommends micro clover at 5 to 10 percent by weight with Kentucky bluegrass or tall fescue.

What daily mowing does to flowers and bees

This is where robot mowers and clover lawns pull in different directions.

• Less mowing, more flowers. A USDA Forest Service and UMass Amherst study of suburban lawns in Springfield, Massachusetts, found lawns mowed every three weeks had up to 2.5 times more flowers than lawns mowed every week. Bee numbers were highest on lawns mowed every two weeks.
• Frequent robotic mowing can reduce clover. A Norwegian research project, summarized by the USGA, found robotic mowing on golf fairways cut at about 0.6 inch reduced the spread of clover by 30 percent in some grasses and almost 60 percent in red fescue, compared with reel mowing. Home lawns are cut far higher, so the effect is likely smaller, but it’s a sign that constant mowing doesn’t favor clover.
• A manufacturer-funded counterpoint. A University of Hohenheim study run with STIHL reported “constant flowering” on robot-mown plots, as plants grew outward rather than up, and recommended the highest cutting height. It comes from STIHL’s own website, so weigh it accordingly.

The practical conclusion: a robot mower on its default daily schedule will keep a clover lawn green and neat, but most flowers will be cut off before bees can use them. To get flowers, change the height and the schedule.

How to set up a robot mower for a bee lawn

1. Raise the height to 3 inches or more. That’s the University of Minnesota’s minimum for bee lawns. Many robot mowers can’t do it: Husqvarna’s 450X NERA, for example, stops at 2.4 inches. Check the U.S. listing’s stated maximum.
2. Mow every 2 to 3 weeks, not every day. Most apps schedule by day and time, so allow one or two days every other week. Expect the mower to work harder on those days.
3. Pause during full bloom. The University of Minnesota says to hold off while flowers are in full bloom. White clover blooms from late May to October, peaking in June in Minnesota.
4. Or split the lawn. Keep the areas you walk and play on as regular mown lawn, and make a clover or bee-lawn area a separate zone or a no-go area mowed only occasionally. Husqvarna’s Rewilding Mode does something similar automatically, leaving 10 percent of the lawn unmown. Robot mowers and multiple zones explains how zones differ between brands.
5. Remember the bees. The University of Maine warns that bees on clover flowers are a hazard for bare feet. Waiting until a bloom has finished before mowing, as Minnesota recommends, also avoids running the mower through bees at work.
6. Mow in daylight. Research at the University of Oxford found hedgehogs are vulnerable to robot mowers at night, and GARDENA advises daytime-only mowing to protect wildlife. America has no hedgehogs, but toads and other small animals are active after dark too.

The picks

Smaller robots handle clover too. Tom’s Guide’s reviewer found the compact Navimow i110N went “fighting through clovers and crabgrass” without getting caught up. Its range tops out at 3.6 inches, enough for a bee lawn on a small lot.

Wet clover and wheel wear

Clover is softer and more slippery than grass. Robot mower makers say wet grass reduces wheel traction: Segway says wheels can’t keep enough grip on slippery, wet grass, and Mammotion says moisture reduces traction on slopes. Put the two together and a clover lawn is more likely to show wheel marks on dewy mornings or after rain. Use the rain sensor or rain delay, and schedule clover areas for later in the day. Robot mowers in rain and wet grass covers the settings, and will a robot mower damage my lawn? covers wear paths.

Micro clover is usually mixed into tall fescue, which has its own height needs. See robot mowers for tall fescue.

Questions

Can you use a robot mower on a clover lawn?

Yes. Purdue says white clover tolerates close mowing, so a robot mower won’t harm the clover itself. What you lose with daily mowing is the flowers, so if you want a flowering lawn for bees, raise the cutting height and mow far less often.

How high should you mow a clover or bee lawn?

The University of Minnesota recommends mowing bee lawns at 3 inches or higher, about every 2 to 3 weeks, and holding off while the flowers are in full bloom. Robot mowers that reach 3 inches or more include the Mammotion LUBA 3 AWD H versions and the Segway Navimow X3 series, both up to 4 inches.

Will a robot mower kill micro clover?

Mowing isn’t the main threat. The University of Maryland says micro clover starts to die back when cool-season grass goes dormant in summer heat and needs reseeding to persist, and most broadleaf herbicides kill it. A robot mower set to a sensible height won’t wipe it out.

Do robot mowers reduce clover in a lawn?

On golf turf, yes. A Norwegian research project summarized by the USGA found robotic mowing on fairways cut at about 0.6 inch reduced the spread of clover by 30 to almost 60 percent compared with reel mowing. Home lawns are cut much higher, so the effect is likely smaller, but frequent mowing doesn’t favor clover.

How often should a robot mower run on a clover lawn?

It depends on what you want. For a tidy clover-and-grass lawn, a normal robot schedule is fine. For flowers, a USDA Forest Service study found lawns mowed every three weeks had up to 2.5 times more flowers than weekly-mowed lawns, and bee numbers peaked when lawns were mowed every two weeks.

Is clover slippery for a robot mower?

It can be when wet. The University of Maine says clover is quite slippery when wet and crushes more easily than grass, and robot mower makers say wet grass reduces wheel traction. Use the rain delay and avoid mowing clover early on dewy mornings.

The short version

A robot mower won’t hurt clover, but a daily schedule removes the flowers. For a green clover-and-grass lawn, mow as normal. For a bee lawn, follow the University of Minnesota: 3 inches or higher, every two to three weeks, and a pause in full bloom. The LUBA 3 AWD H and the Navimow X3 reach 4 inches. Husqvarna’s Rewilding Mode leaves a flowering patch automatically. Keep it off wet clover, and mow in daylight.