Steam weeding masthead

"Simplicity is the ultimate sophistication" Leonardo Da Vinci

PhysicalWeeding a company that designs specialist physical weeding machinery as well as providing consultancy and advice on all aspects of physical, cultural and biological (non-chemical) weed management for commercial agriculture.

It is owned and run by Dr Charles 'Merf' Merfield, an international organic / sustainable horticulture scientist specialising in weed management and machinery and Tim Chamberlain a pioneering and multi-award winning organic farmer from New Zealand.

Our philosophy is to create exceptionally effective and reliable machines without unjustified complexity based on the premise that simple is superior. Our aim is be the one-stop shop for machinery and information on non-chemical weed mangement for commercial farmers and growers. This is increasingly important now that significant problems are emerging with herbicies, espicially herbicide resistence: PhysicalWeeding is plan B for a post-herbicide world.

Please note, all machines on this website are © copyright except the 4 Wheel Hoe and the Merf Clamp. You may not copy the designs, even with significant alterations, without permission, which can be obtained by contacting us.

Free stuff!

The 4 Wheel Hoe (pedestrian wheel (push) hoe) has been released under an Open Hardware License so that anyone can now download the plans for free and build their own machine

The Merf Clamp An individual axis locking, toolbar clamp, for weeding machinery and other uses, has also been released under an Open Hardware License

Machines for sale

Steam weeders

Flame weeders

False seed bed tillers (cultivators)

Consultancy, information and advice

Physical weed management information including false and stale seedbeds, the principles of thermal weeding and a comparison of the pros and cons of steam vs flame weeding.

Consultancy services

Other information

Contact information

About us

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Website legal information

Photo of superb weed management due to highly effective use of false and stale seedbeds not hoeing

Superb weed management in a commercial crop of organic (non-herbicided), direct drilled, leaf beet. This is typical of the level of non-chemical weed control that is now achievable. The crop has not even had any post crop-emergence weed control, e.g. hoeing. Weed management has been achieved by good rotations, preventing weed seed rain and false and stale seedbeds.


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Copyright 2009 Steam Weeding Ltd. PhysicalWeeding is a trading name of Steam Weeding Ltd. a New Zealand registered limited company.