Herbicide use in horticulture - a defence
I thought my latest Scribehound piece might 'set the cat amongst the pigeons' so I've written this which I hope clarifies and explains my position.
I think it is important that we can have grown-up discussions about herbicide use in horticulture and landscape management and not immediately fall into knee-jerk responses and consider our methods on the basis of evidence, rather than ideology.
For a start glyophosate/Roundup has an image problem, having been originally developed by the Monsanto corporation, around which there has been the most extraordinary amount of, to be quite honest, hysterical opinion, much of it linked to the company's investement in genetically modified crops in the early 2000s. It is important we look at facts rather than listen to emotive, and often irrational propaganda from campaigners whose grasp of the science has often been very shaky.
Glyphosate has been around a very long time, which in itself attests to its relative safety. There have been a great many studies which support this; chiefly low toxicity and crucially the fact that it is absorbed onto soil particles very rapidly, so inactivating it, followed by microbial breakdown to phosphates, CO2 and water. Only on very sandy or gritty soils, with few clay, organic or other colloidal particles, is there a danger of leaching down into the water table (my Portuguese neighbours please note!).
For us, in ornamental or biodiversity-supporting horticulture, it is crucial to emphasise that we are talking about minimal use: once, +a possible follow up, for clearing a site of unwanted vegetation, or very occcasionally and very strategically for dealing with particularly invasive species. Comparisons with agriculture are not helpful, as these are nearly always on an annual basis and far more extensive anyway.
Glyposate and Triclopor containing herbicides are incredibly effective and accurate tools for dealing with unwanted aggressively spreading plants, one squirt killing getting to an entire root systems with surgical provision. There is simply no physical means of achieving the same result. Their ability to do the job without soil disturbance (which brings a crop of weed seeds to the soil surface) is extremely useful.
I would also like to point out that the cost-effectiveness of strategic herbicide use is a particular benefit for cash-strapped local government, community groups, conservation organisations or simply those with limited budgets.