Business Monday: This Hilo entrepreneur kills weeds with safe steam, not herbicides

With growing environmental and health concerns about the use of herbicides, an entrepreneur on the Big Island is offering a safe method to kill weeds. Steve Hambly is using steam.

“It’s kind of like cooking spinach on the stove,” said Hambly, owner of Steam Weeding Services in Hilo. “You can see the results right away without having to use something toxic on the vegetation.”

Steam weeding is the process of using steam and hot water to heat the water within plant cells, causing them to burst and effectively cooking the plant from the inside. The method kills the plant, but also breaks down seeds in the soil, preventing future weed growth.

Hambly saw how steam weeding worked more than 25 years ago when he watched his father use a a homemade contraption that created water hot enough to kill weeds around his garden in Portland, Oregon.

This intrigued Hambly for a long time. Finally, he spent his free time conducting his own research and saving the thousands of dollars it would require to buy a machine he not only could use on his own property, but also use to create a business.

After he moved to Hawaiʻi Island in 2020, the idea of starting a steam weeding business continued. He finally was able to buy his own machine in 2023 from an Australian company, Weedtechnics. He didn’t disclose how much he spent, but machines on Weedtechnics website range from $17,000 to $48,000.

Hambly’s machine, which is powered by a small gas engine, uses the company’s patented technology, Salusteam, to weed control.

The process uses pressurized water that is heated by a diesel boiler to 248° Fahrenheit and then delivered to weeds gently at 40 to 60 pounds per square inch. At 212° Fahrenheit, the plants’ cells burst on contact and the waxy cuticle of the plant is destroyed. This leads to rapid dehydration and decomposition in the soil. 

According to Weedtechnics, the Salusteam turns the weeds into cooked vegetation that is initially a thin layer of mulch that turns into the humus layer (top layer) of soil over time. A study by Australian permaculture students also found that there is an increase in microbial activity after steam treatment breaks down the desiccated weed material into soil organic matter.  

“Not only are the results visible immediately, there is also evidence that steam weeding is beneficial to the soil long-term,” Hambly said. “Most customers are very impressed by the immediate results, and I hope they see a positive effect with their crops over time.”

As proof that it works, Hambly shared before and after photos of his own property on the social media page of his Steam Weeding Services. In 2024, he gained clients eager to steam weed their lawns, gardens and orchards.

Hambly’s service is $80 an hour. He can cover 400 to 1,000 square feet of land an hour depending on if the client wants spot treatment or full coverage.

One of his favorite parts about his business is showing people across the island an effective method of weed management that negates the use of herbicides.

“The benefits to me are huge, because it means less people are using poison,” he said. “There is no run-off into water sources. No harm to people or pets. And, you can do specific targeting with the machine.”

He said there also is no spray drift, so nothing is killed by accident.

“I can kill weeds around fruit trees, garden beds and ornamental plants, and the water won’t cause any harm,” Hambly said.

On Saturday, Hambly spent about 3 hours weeding a fruit orchard to help the owner better walk through the space.

“This job would not be possible to do with herbicide without harming the trees,” Hambly said. “Itʻs a big job that has taken about 15 hours in total to complete, but I love doing the work and [the property owners] really appreciate it.”

According to Hambly, customers may need to get a steam weeding treatment every 3 to 5 weeks, which is similar to herbicide treatments. However, every time the weeds are sprayed with the steam, the seed bank reduces in size and will create less weeds over time.

While Hambly mainly uses his machine to weed properties across the island, he is also able to use it to pressure wash for residential cleaning, which is done even more effectively with the heat. He has used it to clean walkways, house siding, roofing, rock walls and has even been able to remove graffiti on walls.

Hambly hopes to grow his clientele, so he can run his business full time one day. Until then, he will steam weeds on the weekends and continue working at Hawaiʻi Care Choices hospice facility in Hilo during the week.

“I think a lot of people don’t know much about this method, but many of my clients are excited with the technology, because like me, they donʻt want to use poison of any kind, especially around their valuable gardens and orchards,” Hambly said. “My ultimate goal is to do this job full time because I absolutely love it and believe in how it is changing the idea of weed control.”

Visit the Steam Weeding Services Facebook to learn more about Hambly’s work and call 808-765-5630 to schedule an appointment.