how it

Tertill lives in your garden and prevents weeds from becoming established. Using unique design elements and a variety of sensors, Tertill patrols the garden daily, avoiding plants and obstacles while looking for weeds to eliminate.

Tertill has a very simple method.

Weeds are short, plants are tall. A plant tall enough to touch the front of Tertill’s shell activates a sensor that makes the robot turn away. A plant short enough to pass under Tertill’s shell, though, activates a different sensor that turns on the weed cutter.

Features & Benefits


Gardeners often forget to weed but weeds never forget to grow. At one time or another most of us have been dismayed to find a once pristine garden “suddenly” choked with weeds. We all intend to give our gardens regular attention but sometimes life gets in the way. Not so for Tertill. Tertill’s only purpose is weeding, so it never forgets, never gets distracted, and never goes on vacation.


All the fertilizer, all the water, and all the sunlight that reaches your garden should go to growing healthy, productive crops. But weeds use these resources, too, depriving them of the light and food they need to thrive. By keeping the weeds from establishing themselves, Tertill makes sure that your plants (the good ones!) get all the resources they can.

gardening limitations

Gardening offers great benefit to the gardener. It gives us time outdoors surrounded by growing plants, it’s good exercise, it rewards us with delicious, fresh food, and it is a source of pride and accomplishment. But older folks or anyone with a mobility challenge may find that their physical limitations force them to cut back on gardening. Tertill can help. Because weeding is often the most arduous gardening job, assigning that task to a robot can help the gardener keep doing what they love.

no herbicides

Gardeners with persistent weed problems sometimes resort to chemical herbicides to protect their crops. But by patiently chopping weeds when they are small, Tertill keeps weeds well controlled using only mechanical means. The expense, the hassle, the danger to children and pets, and the worries associated with chemical herbicides are eliminated. (Have you ever actually read what you’re supposed to do with herbicides? There’s a lot to it.)

robotic awesomeness

People have been trying to get weeds out of their garden for a long time: they have tried plastic groundcloth, homemade herbicides, boiling water, and countless other approaches. But all of these remedies lack a certain robotic awesomeness that Tertill brings to the situation.

solar powered

Solar powered, so you don’t need to charge it.


Tertill uses bluetooth to talk to your smartphone.


No need to bring Tertill in when it rains.

Did I see Tertill on Kickstarter or Indiegogo?

Maybe! We ran successful campaigns on both platforms and we’re appreciative of the support of our backers and their assistance in making Tertill a reality.

Our campaign video has some more details on Tertill, its operation, and Franklin Robotics, the company behind it.

How does it know a weed from a plant?

Because Tertill’s approach is height-based, put one of the provided plant guides 
around short plants until they are tall enough for Tertill to recognize.
When Tertill approaches the guide, it will recognize it and turn away.

How does it remove them? won’t the weeds just grow back?

Tertill whacks weeds using a spinning string trimmer, which cuts the weed off near the ground. Because Tertill lives in your garden and goes looking for weeds every day, weeds are always small when the robot finds them. A whacked weed may sprout again, but sprouting takes energy stored in the seed or root. By coming back every day, Tertill never lets a weed develop the leaves it needs to replenish this energy, so eventually the weed gives up and dies.

How does Tertill know where the edge of my garden is?

There needs to be at least a short barrier around your garden to keep Tertill from wandering away. The barrier might be a fence, edging that’s two inches or taller, or the wooden border of a raised bed. Tertill has a simple, reliable strategy to ensure that it covers the garden. It uses a combination of bouncing away from, and sometimes following, obstacles and plants. This is the same strategy employed by some models of Roomba and other robotic vacuums.

Does Tertill run continuously?

No. Although Tertill is always charging from whatever sunlight is available, that’s only enough energy to run for about an hour or two per sunny day. Tertill will wake up every 20 minutes or so, and if there’s enough energy it will run for a little bit, and if not, it will check again later. This video shows two robots in a garden that is ~175 square feet.

More details are available on our support site.

How often do I need to charge Tertill?

Tertill gets its power from the sun. When there is sunlight—even on cloudy days—Tertill’s solar cell converts the light into electricity. The robot stores the energy in a battery. You don’t need to charge or replace Tertill’s battery. Tertill uses its stored power smartly—during cloudy stretches, when less power is available, it patrols for weeds less often. Tertill is more aggressive during periods with more sun. Fortunately, weeds grow more slowly when they have less light.

Does Tertill run all the time?

No. Because Tertill uses energy faster than it can be gathered from the sun, Tertill ends up running for about an hour or two every day.

Do I need more than one?

Most gardeners will need only one robot. If you have an unusually large garden (good for you!) you might get better performance with more than one robot. (The area of a typical garden in the US is about 100 square feet.

Will Tertill get stuck?

Tertill uses four-wheel-drive. This helps Tertill move through soft soil, sand, and mulch, and also helps Tertill climb slopes. Its distinctive diagonal wheels make Tertill more stable on slopes and help it get past certain terrain challenges. Tertill relies on several sensors and clever programming to keep out of trouble. To detect objects like the garden fence and big plants, Tertill uses sensors similar to those found in many smart phones—the lightest touch is all it takes. To detect steep slopes, Tertill uses the same sort of sensor that tells your cell phone which way is up. Tertill can also sense if a motor stops turning—perhaps jammed by a rock—so it can protect itself from damage.

Purchase Tertill today!