Robotic Mowers 101

Robotic Mowers 101

Robot Lawn Mower Basics

Robots aren't confined to the realms of science fiction. Believe it or not, the first robotic lawn mower debuted in 1995.

Thanks to improvements in technology, along with changing consumer tastes, lawn robots are now more widely available and affordable than ever. 

However, as common as automatic lawn mowers are becoming, you still might have some important questions before you buy one.


Why Robo Mowers Are Awesome!

Robotic Lawn MowerRobotic mowers are small, battery-powered machines that measure about two feet in length. They use an electric motor and internal computer hardware to trim your grass in a completely different way from traditional mowers.

One difference you'll notice is the frequency of mowing. Previously, you might have planned to use your traditional push mower every Saturday. In contrast, as long as your automatic lawn mower is powered on, it will mow your lawn every day (or as often as you set it) for a fresh, well-kept appearance.

As a result, you'll see a robomower use a different style of mowing. You shouldn't expect a robot lawn mower to create stripes on your lawn or to tear large sections of each blade of grass as a rotary blade mower would. Instead, a robomower will clip small portions of each blade for a uniform look across the lawn.

Because robotic lawn mowers are too small for a collection bag, they leave those small clippings on the ground. The clippings serve as fertilizer and return nutrients to the ground, which can improve your lawn's health.

However, the biggest difference is the need to program your mower. Don't let this part scare you. You won't need an engineering degree to do it. In fact, you can control everything from your mobile device or a smart home hub in some cases. 

Robotic Mower App

Both major robomower brands, Husqvarna and WORX, have a mobile app from which you can control:

  • The time of day you want your mower to operate
  • The size of the area your mower should mow
  • The height at which you want to cut your grass

As you can see, robotic mowers are radically different from traditional mowers in several beneficial ways. You may have to let go of preconceived notions about lawn mowing when buying one, but if you can do that, you'll quickly realize the value of robotic mowers. We're here to help you take that leap of faith.


How Do Robotic Lawn Mowers Work?

As smart as autonomous lawn mowers are, they don't automatically travel toward patches of long grass. Like children, they need you to set their boundaries.

To set a robot lawn mower's path, you need to install the boundary wire included with your mower along the perimeter of your yard and along the edges of any areas you don't want to mow (for example, a garden). If your yard is split into two areas by a fence, your robotic mower can handle both if the boundary wire is properly connected.

How to Lay Robo Mower Boundary Lines

The wire can be laid on top of the ground, where it will lie close to the grass's shallow roots. It is then held in place with stakes, making setup easy to finish within a few hours.

Guide Wire SetupYou also can dig a shallow trench for the boundary wire. This takes more time, but it places the wire out of the way so that people are less likely to trip over it.

Many robotic mowers can be programmed to cover a certain distance in one session - for example, a quarter acre. Once the boundary wire is in place, the automatic mower will mow a course starting along the boundary wire and continuing in straight lines until it has mowed the equivalent of the programmed distance.

Advanced robot mowers have built-in GPS capabilities. GPS allows a robomower to create a map of your lawn for even more mowing finesse - for example, for starting in different sections of your yard each time it goes out.

When the mower's battery is low, the mower will travel back to its docking station so that the battery can charge. Once the battery charges, the mower will finish the job. Depending on your brand of mower, it can either follow a guide wire back (Husqvarna) or follow the perimeters of the boundary wire (WORX). A guide wire is a separate wire that helps the mower navigate back to the docking station if it is in a remote part of the yard.

The docking station should be positioned close to the guide wire on a flat surface near an electrical outlet where it can be plugged in. A dry spot such as the space under a deck is ideal.

Positioning a Robot Lawn Mower Docking Station

Always check your mower's user manual; some recommend that the docking station be placed in a covered or sheltered location at the edge of your yard, such as a shed.


Will a Robotic Mower Work on My Lawn?

If a robotic mower is a purchase you're considering, there are three details regarding your lawn that you should keep in mind:

  • The size of your yard
  • The type of grass growing
  • The degree of your ground's incline
  • Objects and obstacles in your yard


Yard Size

Just like walk-behind lawn mowers, robotic mowers come in a variety of sizes that make them better suited to handling different amounts of terrain.

Larger robomowers are capable of mowing medium to large properties up to 1 1/4 acre on a single battery charge. Smaller robomowers are better suited for lawns 1/4 acre and under.


Type of Grass

Blades Attached to Rotating DrumUnlike traditional mowers that use propeller-shaped rotary blades to cut grass, robotic mowers use smaller blades fastened to a rotating drum underneath the mower to clip the grass instead of tearing it.

Cool-season grasses such as Kentucky bluegrass, which tend to be thinner, thrive when cut with a robotic mower. Warm-season grasses such as bermudagrass are thicker but still can grow well when cut regularly.

The takeaway is that robomowers work best when they're allowed to run as intended: every one or two days, cutting the grass to a height between 1" and 3 1/2". Frequent and regular use allows them to clip even thicker bent grasses (although robotic mowers aren't recommended for wet grass).


Ground Slope and Incline

Robotic mowers have a strong advantage over walk-behind mowers when mowing a hilly yard: you don't have to use your strength to push them!

Maximum 30-Degree Slope for Robotic MowerDepending on the model, automatic mowers are suitable for mowing ground with inclines up to 30 degrees. Always check the incline recommendations for your mower before using it on a hill.

Also note that robomowers require much lower slopes close to the guide wire. Boundary wire should not be placed on ground with an incline greater than 15 degrees.


Yard Objects and Obstacles

Robotic mowers do have sensors that can detect large objects in their paths, such as lawn furniture and trees. For safety reasons, keep pets and small children away from the lawn while the mower is operating.

Robotic mowers cannot detect common small objects that might be left on lawns:

  • Pine cones
  • Sticks
  • Pet toys
  • Garden tools
  • Pet waste

Remove small objects like these manually before your mower begins mowing. (Yes, that means not letting the dog droppings pile up!)

Automatic mowers also have difficulty traveling over tree roots and bumpy, uneven lawns. Consider rolling your lawn before installing your robotic mower.


Are Robotic Mowers Safe?

Manufacturers understand that automatic mowers present safety concerns for many users. However, your smart lawn mower has features that were designed with safety in mind:

  • Emergency stop buttons
  • Object sensors
  • Blades away from the edges
  • Automatic shutdown
  • Theft protection


Emergency Stop Button

Emergency Stop ButtonOne of the most reassuring safety features found on robotic mowers is an emergency stop button that requires only a simple push to operate. The large button is found on the back of the mower.


Object Sensors

As mentioned earlier, sensors built into the mower detect large objects in the mower's path so that it can stop and change direction. This includes children and pets, although to ensure their safety, you should keep them off the lawn while the mower is operating.


Shorter Blades

Robotic Mower BladesInstead of the long, propeller-like rotary blades that walk-behind and riding mowers use, a robot lawn mower uses small blades secured to a rotating drum beneath the mower's body. These blades don't extend as far as rotary blades.


Automatic Shutdown

Many models of robot lawn mower will stop running automatically if they reach too steep an incline or if someone picks them off the ground.


Theft Protection

Robomowers can be lifted from the ground, but features like these keep them from being carried away by thieves:

  • An alarm that sounds when the mower is removed from the boundary area
  • A physical security key that needs to be inserted and turned to shut off the alarm
  • A PIN that needs be entered to program the mower


How Do I Take Care of a Robotic Mower?

Because robotic mowers don't have gas tanks to fill or oil to change, they require low maintenance.

Aside from cleaning grass clippings from the body (always turn off your mower before cleaning it), the most important maintenance task you'll have to take care of is changing the blades every one to two months, or after every 500 hours of use, due to the frequent mowing schedule.

Depending on the model, changing the blades can be as easy as unscrewing the old blades from the drum and fastening the new blades in place. Follow the instructions in your mower's user manual for changing the blades.

When putting your robotic mower away for the season, be sure to remove the battery and store it in a cool, dry place indoors.


Robotic Mower Tips

Here are some tips and things to keep in mind when owning a robotic mower:

·       You will still need to do your own trimming along sidewalks and landscaping, as a robotic mower won't be able to mow the parts of the lawn where the boundary or guide wire is sitting.

·       Once you install the boundary and guide wire, don't forget about it, especially if you plan on doing raking, dethatching, aerating, or other yard maintenance that could damage it. To prevent any issues, be sure to bury the wire. We recommend staking the wire down and testing the mower's performance for a month before burying the wire to ensure that you'll never have to dig twice.

·       If you have sprinkler heads that come out on a schedule, make sure that schedule doesn't overlap with your robotic mower. Otherwise, the mower may run into the sprinkler heads or sustain water damage.

·       Be patient when first trying your robotic mower. Over the first few weeks, it will be in a learning phase. Once that learning phase has passed, the robotic mower will understand the intricacies of your lawn and be able to produce better cutting results.

·       To create no-mow zones, or "islands" in your lawn, such as around a tree in the middle of the yard, lay out two wires next to each other around the obstacle. Just make sure never to cross the wires, as that will confuse the mower.


The Future Is Now

Many homeowners want a great-looking lawn but are unable or don't want to mow themselves. Hiring a lawn care service is an option, but the recurring expense might not be practical.

Thanks to advances in robotic mowers, homeowners don't have to give up a ton of money and time to have a healthy, attractive lawn. The affordability and ease of use of robotic lawn mowers can make that a reality today.


NEXT: Shop All Robotic Lawn Mowers

Dale, the Power Equipment Expert
Power Equipment Expert
Was this article helpful?