As awareness grows around the risks associated with chemical herbicides, more organisations are seeking safe, effective, eco-friendly weed control alternatives for their outdoor spaces.
Boiling water is one weeding method rapidly garnering interest. The hot water melts the waxy protective coating of the weed, rupturing its cell structure and causing it to dehydrate. While its immediate visual impact looks promising, boiling water has several limitations as an effective, long-term, scalable weed treatment for councils, landscapers and organisations with large outdoor facilities.
Does boiling water kill weeds?
Any form of weed heat treatment must achieve and maintain ‘kill zone’ temperatures (above 57°C) to effectively damage the plant structure and allow efficient thermal heat transfer from the leaf to the root. In fact, research shows that stable delivery of heat at 80°C for the first five seconds is crucial to ensuring the most effective plant kill.
The challenge with boiling water for weed control is that it quickly loses heat to the atmosphere, reaching around 64°C at weed contact and quickly dropping out of the kill zone thereafter.
While it typically wilts the foliage it comes into contact with, the rapid temperature loss impacts the thermal transfer to the root. This lower kill rate requires a higher number of treatment cycles, increasing treatment and labour costs.
The efficacy of boiling water is further reduced in wet and windy weathers, causing downtime and impacting treatment schedules.
What types of weeds is boiling water most effective on?
Hot water is typically most effective on young, annual weeds. It works best on surface-level weeds that don’t have a deep or established root system, or hard-surface weeds growing in between or on paving that don’t have the protection or insulation of soil.
It’s usually less effective on more established, perennial weeds that have stronger and deeper root structures, like dandelions, as their roots are harder to reach and heat is quickly lost to the atmosphere.
Why does foam weed control work?
Hot water alone as a weed treatment has its flaws. While some recommend the addition of salt to increase its efficacy, this can damage the soil and related ecosystems.
However, the addition of foam significantly improves its efficacy. As the leading herbicide-free weed control solution, Foamstream pairs hot water with an insulating organic foam, made from plant oils and sugars. When applied to weeds, this foam blanket ensures the temperature is retained above the kill zone.
According to a University of Pisa study, this brings, ‘advantages of less water being required, less susceptibility to weather changes, a high application accuracy and speed, more heat transfer time, and a low cost.’ It found 100% weed devitalisation with foam doses from just 5 L/m².
As the only system on the market with an electronically-automated dual phase burner, Foamstream guarantees stable temperature and pressure for effective thermal transfer to the roots.
It’s proven to kill over 95% of weeds on first application (compared to 50–60% for hot water) and requires 75% fewer treatment cycles per year than steam or hot water.
Among its benefits, Foamstream sterilises surrounding seeds and spores to prevent future regrowth.
How to use foam weed control to kill weeds
It’s quick and easy to get started with Foamstream, and it requires no certification or formal training:
- Foamstream is delivered through patented machinery, whether a compact, portable model or a vehicle-mounted.
- The machinery comes with a hose and lance, allowing operators to cover large spaces quickly and tackle hard-to-reach areas. There are different lance heads for various uses and applications.
- The Foamstream mix flows from the lance, covering the vegetation and sterilising surrounding seeds and spores.
- The foam blanket retains kill zone temperatures, allowing the heat to effectively. penetrate the leaf, stem and root structure and sufficiently damage or kill the weed
- The foam is biodegradable, and the weed gradually decomposes and returns its nutrients to the soil.
Rethinking weed control
While boiling water undoubtedly brings safety and environmental benefits over herbicide weed killers, there are alternative solutions on the market proven to deliver a more efficient, cost-effective and reliable kill. We explore these in greater detail here.
Foamstream also brings the benefit of scalability, and is used by councils, landscapers and grounds maintenance professionals across the globe as a safe, compliant, effective weed control solution. Get in touch to learn more, or if you’d like to see Foamstream in action for yourself, why not book a demo?
