I well remember being introduced to my very first selective weed killer.
I was relatively young and had not paid much attention to what my parents did in any of the gardens of the houses in which I grew up. Yes, yes, I had cut the grass; I had fetched sack loads of free-to-take-away leaf mould from a local authority compost heap; I had helped with the hoeing and the hand-weeding: but I hadn’t paid much attention to the clever things my parents were doing.
Then, all of a sudden, I was married and we had a garden of our own to care for, a garden which was largely devoid of plants when we moved in to our first home. What was to be done? We decided to follow the example of our immediate neighbours and plant roses, which we duly did, travelling to Aberdeen to buy some plants from Cocker’s Roses. Struck by the weed-free nature of their rose beds, I learned about simazine, a herbicide which was used after ground had been cleared of weeds to prevent them from re-appearing. Magic!
The years have rolled by since then – but weeds still want to grow wherever they can in my garden. I have not used simazine for many years now and think it is no longer available to amateur gardeners in any case. But I do use selective weed-killers, particularly those which can be sprayed carefully on to the foliage of unwanted plants … and prove fatal as the plant ingests them through its leaves, allowing the active chemical to invade the shoots and the roots and killing the whole plant … but which are deactivated on contact with the soil so that they don’t affect the unwanted plant’s neighbours and supposedly don’t poison the ground. These herbicides are also magic!
The most widely-used weed-killer worldwide is based on a chemical called glysophate which, and here I quote, “is a broad-spectrum systemic herbicide and crop desiccant. It is an organophosphorus compound, specifically a phosphonate. It is used to kill weeds, especially annual broadleaf weeds and grasses that compete with crops.” Recently, however, glysophate has been the subject of contradictory findings in scientific studies on the carcinogenic risks of the chemical. This disagreement within the scientific community has, not unnaturally, led to concern among politicians all round the world about its continuing use. This concern can be exemplified by these words from Bart Staes MEP, the Green’s environment and food safety spokesperson, who said: “There are clear concerns about the health risks with glyphosate, both as regards it being a carcinogen and an endocrine disruptor.” However, to illustrate the extent of the disagreement about the use of glysophate, the European Food Safety Authority issued a statement in November 2015 which concluded with these words: “The substance is unlikely to be genotoxic (i.e. damaging to DNA) or to pose a carcinogenic threat to humans.”
So can I/should I still use a glysophate-based weed-killer? Well, the present position is that the European Union (EU) has asked the European Chemicals Agency to investigate whether glyphosate can cause cancer, interfere with reproduction or damage the human hormone system. The agency’s report will not be published before the middle of 2017. In the meantime, some important EU member states … such as France, Netherlands and Sweden … are demanding that, if it is not to be banned throughout the EU immediately, glyphosate should be licenced for use for a limited time and solely for agricultural purposes. The United Kingdom government currently opposes any such ban. So where does this leave the Scottish gardener? I just don’t know. I think you pays your money and you takes your choice.