RAMM RootWave Pro gets a new name and a new application

ARTICLE

GARDEN AND PARK TECHNOLOGY

Heleen Kommers, Tuesday 25 November 2025

158 sec

Targeting giant hogweed with electricity

When sap from giant hogweed comes into contact with your skin and sunlight hits it, it causes large, painful blisters. Protective clothing and gloves are essential. "In spring, you can literally hear the sap bubbling inside the stems, which I often compare to thick organ pipes," says Gerrit van Nieuwenhuizen of RAMM. "We use the RootWave Pro for controlling the plant. We supply this machine to contractors in the Netherlands."

Treatment of giant hogweed from a distance

The RootWave Pro is a machine for electrothermal weed control, used for example in public green areas. An electrical charge flows through the stem and root of the plant. Due to the plant's natural resistance, heat builds up and cell walls burst. As a result, the plant dies from the inside out. The method is selective and chemical-free. Because heat only develops inside the plant, the risk of damage to surrounding vegetation is minimal. The system can be used on pavements, squares, parks and tree pits — suitable for municipalities, contractors and landscapers working on chemical-free management in and around cities.
Van Nieuwenhuizen: "The method is widely used for Japanese knotweed control and, to a lesser extent, giant hogweed. Giant hogweed is still sometimes dug up. In that case you still need to protect yourself from the sap. For safe treatment, cut the flowering stems down to knee height so they don't fall on you during the process."

The method can be applied on pavements, squares, parks and tree pits where sustainable and safe control is required.

From RootWave to Electro Lance

RAMM Netherlands previously imported the RootWave from the UK and, together with the German dealer, eventually took over the entire RootWave Pro business. "We bought the full stock. That stock is now gone. With the German company Kersten Arealmaschinen, we will produce new machines. Apart from a few technical details, the machine will remain the same. But this is the right moment for a new name; the working name for now is Electro Lance."
The name brings to mind a Star Wars-style light sabre, Van Nieuwenhuizen notes, a fictional energy blade that cuts through almost anything. "In the countries where we are active, people understand the meaning of the name. It will also be clear in Scandinavia and Spain. We are exploring cooperation with those countries."

The RootWave Pro

Controlling plants from the inside

The future Electro Lance has two thick power cables. One connects the Electro Lance to the grounding pin, which is placed next to the giant hogweed or other unwanted vegetation. On the other side is a 20-metre cable with a lance featuring a three-position switch. This determines whether the plant receives a 3,000, 4,000 or 5,000-volt pulse. The electrons travel through the stem, roots and soil toward the grounding pin, killing the plant from the inside.
Van Nieuwenhuizen: "Pruning stimulates growth — here you prune both the stems and the roots. I usually advise digging out unwanted plants with a loader or shovel. Loosen the roots 20 to 30 centimetres deep, remove them, and treat any remaining parts for a few seconds with the Electro Lance. With persistent species like Japanese knotweed, repeat this three to four times a year for about three growing seasons; then the roots won't return. Giant hogweed produces thousands of seeds. If it's been there for a few years, the soil is full of them, so you need to monitor regrowth for a while."

"Pruning stimulates growth — here you prune both the stems and the roots."

"Giant hogweed responds well to treatment"

Stefan Verstappen specialises in the safe control of invasive species and works extensively with the RootWave Pro. In 2023 he founded INVA, a company focused entirely on managing species such as Japanese knotweed, giant hogweed, water primrose and Himalayan balsam. "Ninety percent of our work is Asian knotweed control, mainly Japanese," he says.
Verstappen has used the RootWave Pro since 2019 and now owns three machines. For large areas he combines them with a Zasso weed-control machine: a tractor-mounted arm removes vegetation first, followed by treatment with the RootWave Pro. For smaller sites he uses the RootWave Pro directly.
Giant hogweed, in particular, responds well to the method. "Electricity allows very targeted work. You only treat the plant you want to remove, without harming its surroundings. Root fragments left in the soil after digging are no problem — the RootWave Pro handles them. The method is efficient and thorough."

Verstappen with the RootWave Pro

Annual RAMM refresher course

RAMM offers an annual refresher course for users on working safely with the RootWave — soon to be the Electro Lance. Key safety tips are also available on the website of this specialist in machines for cultural engineering and agriculture.

Gerrit van Nieuwehuizen, director RAMM

Stefan Verstappen, founder INVA

This article was originally published on 10 November 2025 on the website of Stad + Groen.

RAMM B.V.

INVA

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