At the Gardens we are always on the look out for weed killing devices that don’t include toxic chemicals. Hot water, or steam, is a good option.
At home I’ve used boiled water from a kettle to kill weeds in the cracks in our concrete path, with varying success. But there are high tech variants of this method available, and we are using one called ‘Weedtechnics’. Sorry to promote one brand, but that’s the one we use.
The idea is to blast the weeds with very hot water, in fact steam - something they don’t particularly like. Basically it cooks them, and in about two days they’ll brown off and die.
Although it uses one of our precious resources, water, it will run on recycled water as well (and we going to install collection tanks in Depot for this purpose). You might also ask about its carbon footprint. On their website, Steamwand boast that this system uses just under 70 kilowatts of energy to heat five litres of water in a few seconds. I’m presuming that is efficient.
The steaming unit sits on a trailer that we can tow behind a ute or tractor and has it's own power supply.
Does it work for us? Senior Horticulturalist Dawson Ougham lists the following benefits in report for our staff newsletter:
• Highly versatile - one machine can perform many tasks
• Vegetation desiccates into the soil improving soil humus
• There are no harmful chemical residues or build up in the soil
• No tillage damage to soil structure
• No root zone damage
• It is safe to use near livestock and waterways
• No risk of spray drift
• Save $ on lost productivity from weather delayed herbicide applications
• Save $ on herbicides
• Accurate programing is achievable for weed control.
Image: At top, horticulturist Adrian Pedra giving weeds hell with hot water. Below, the equipment.