Tertill robot is like a Roomba for your garden

A startup developing a weed whacker robot for gardens just got backing from an industry heavyweight
Written by Greg Nichols, Contributing Writer

It's a Roomba for the garden.

Sure. Slick marketing, right? Hitch your brand's wagon to the best-selling, first-out-of-the-gate home robot that became the industry's first blockbuster.

Well, the claim has a little more weight coming from the guy who invented the Roomba. Famed roboticist Joe Jones is the brains behind a weed whacking robot, which is named Tertill.

Also: Can this ingenious trash collecting robot gamify litter removal?

After leaving iRobot, Jones, who cut his teeth in robotics at MIT's Artificial Intelligence lab (now called CSAIL), turned to agriculture. With a few fellow iRobot alums he founded Harvest Automation, which makes materials handling robots for nursery and garden applications.

In 2015, he co-founded Franklin Robotics, the company developing Tertill.

This week, Husqvarna Group acquired a 25 percent stake in the company. The partnership also brings potential distribution relationships and a deep well of garden industry knowledge to Franklin, which is currently selling direct-to-consumer.

Tertill is a small, cylindrical robot that looks and functions a lot like the Roomba. It autonomously roams gardens, bouncing off objects or following their contours, and hacks down weeds via a small spinning whacker under its cambered all-terrain wheels.


Instead of sensing weeds, a sensor at the front of Tertill's body simply senses contact with objects that are tall enough to bump into. The idea is that plants you want to keep are tall while weeds are short.

Seedlings can be protected from Tertill's whacker via a wire collar that can be pushed into the soil around them. The robot will bump into the collar and redirect.

Though Tertill doesn't actually remove weeds, Franklin claims that repeatedly cutting them down day after day denies the plants the chance to create leaves. Because a weed's growth requires energy, and because the energy in seeds and roots is quickly exhausted, a weed will eventually die if unable to perform photosynthesis.

Also: This autonomous robot can mow the lawn, clean up leaves, and remove snow

Tertill's four-wheel-drive is designed to handle mulch, soft soil, and sand. Though a spinning weed whacker could be dangerous for children and pets, modern sensors are incredibly sensitive. Consumer advocates were concerned about the Roomba's safety early on, but iRobot's device has a solid track record, and its a good bet that Tertill's creators have looked closely at potential hazards.

The robot could be a hit with gardeners, especially those who prefer not to use herbicides.

Franklin is currently manufacturing its first batch of units, which are available for pre-order.

Editorial standards