Environmentally friendly weed killer


Being a man who now owns land, I also now own weeds it seems.  I have weeds in my lawn, weeds in my flower beds, weeds in my gravel drive and weeds growing between my paving slabs.  So how should I deal with these menaces in an environmentally friendly manner?

Weed killer in whatever form is basically herbicide.  While some herbicides are selective, many will kill all plants, whether desirable, or undesirable.  So the use of a typical weed killer in an area where desirable plants are growing is perhaps something to be avoided.  The only method for weed control that is appropriate for these locations is old-fashioned pulling up the weeds on a regular basis.

So that covers the lawn and flower beds, but what about other areas where traditional weed killers might be used?  Traditional weed killers use a range of chemicals, some with significant toxicity and even carcinogenicity.  Weed killers also have known effects on bird populations due to their toxicity.

Armed with this knowledge, I began a search for a weed killer with minimal health and environmental impact.  My local DIY shop only sold traditional weed killer, with active ingredients such as glyphosate, so I turned to the web for inspiration, and there I found a great idea I put to the test.  Several websites and forums recommended a simple home recipe for weed killer – four parts vinegar, one part washing up liquid (that’s dishwashing liquid to you Americans) and one part salt.  Shake it up (though not too vigorously to avoid turning the washing up liquid to bubbles) and put it in a spray gun.  Apply liberally to weeds.

The theory as described is that the vinegar kills the weed (or any other plant you happen to spray, so be careful), the washing up liquid helps the vinegar cling to the leaves of the weed, thus aiding this process, and the salt prevents the weed from re-growing.  This is where I would advise caution; excess salt may render the soil where the weed has grown too saline to support any desirable plants.  That is why I stick with old-fashioned weeding for my lawn and flower beds.

So I tried this recipe, with a certain amount of scepticism, but I was pleasantly surprised with the results.  I had a good number of weed species growing in my garden, including many dandelions, and all have been vanquished by this weed killer.

I was rather limited in the ingredients available for that initial trial, and used malted vinegar and supermarket own-brand washing up liquid.  This concoction worked well, as I have described, and I will continue to use malted vinegar.  However I have had reservations about the use of a standard washing up liquid in the recipe.  Surfactants are a key ingredient in many washing up liquids, and many surfactants are known to cause environmental damage.  Ecover washing up liquid purports to use eco-surfactants that have less environmental impact, and will hopefully not damage my soil or the surface and ground waters it is linked to.  So the second phase of my environmentally friendly weed killer trial will use some of Ecover’s washing up liquid.  Let’s hope it is as successful as the first and I will truly have an environmentally friendly weed killer to recommend.