Tag: Glyphosate

Glyphosate in the Garden

You may want to read Glyphosate the Story to Date first.

First and foremost Glyphosate is not a selective weedkiller, it kills all the plants and grasses you may have in your garden regardless, it may take several applications over several years for particularly persistent weeds but it will get there eventually. Glyphosate works by being absorbed by the leaves and being transmitted to the roots killing the whole plant unlike most herbicides which only kill the top growth allowing the roots to regrow, which is the case with many perennial weeds.

Availability

Although many UK garden centres and supermarkets have removed glyphosate containing products from the shelves it is still freely available online. Unless you are very rich, or have a very small garden, “ready to use” products are definitely not the way to go, far better economically to buy the concentrate. When sold for garden use the product normally contains 300g/l of glyphosate in a soluble concentrate which also includes a wetting agent to help apply the solution to the leaves. These wetting agents have become subjects of controversy themselves as manufacturers do not have to list them in the product’s ingredients.

Application

Without doubt the best tool for application is a knapsack sprayer particularly if you intend to use a “no dig” approach, watering cans are out of the question although some products do give dilution rates for this. It is essential to be in control of the direction and volume of the spray principally to make sure that you only spray the unwanted plants and avoid those that you want to keep. It has been pointed out to me that the most necessary skill when spraying is to actually know the difference between a weed and a keeper, unfortunately many, what I call “mow and blow” garden maintenance people, don’t, best do it yourself. If you have a large garden it’s worth spending a bob or two on a decent sprayer with a metal nozzle, however I manage quite well today in my small garden with a cheap plastic one. If you intend to spray close to plants that you want to avoid, a good idea is to practice with just water first, and of course always point the nozzle away from them, I very often virtually dribble onto the offending weeds to avoid overspray, control is everything.

When and what to spray

As the herbicide is absorbed through the leaves it is essential that no attempt is made to cut back the weeds before spraying however tempting that can be in an overgrown patch, the more leaf surface area there is, the more spray can be absorbed. Old foliage does not take up the chemical as efficiently as new growth, an exception to the rule, in ideal conditions, is to cut back the old growth and then spray the re-growth at a later date to get better absorption. Weeds can be sprayed at any time of the year (it won’t say this on the label) as long as there is growth, however the results will take longer in the cold weather. Patience is a virtue when using glyphosate anyway, I always allow at least a week for it to show signs of acting even in summer.

When it comes to rain, the likelihood is that in ideal conditions for absorption on annual weeds a shower of light rain a couple of hours after spraying may not be too detrimental. If however one is spraying established perennial weeds at least 24 hours without rain is essential. An example of cold weather use is to spray emerging weed seedlings in early spring when the plants in your borders are mainly dormant, this is not necessarily “good practice” as you will get some overspray but it can save a lot of problems later. This particularly applies to the pernicious rock cress which seems to grow all year round.

Speaking of good practice, herbicides containing glyphosate are perfectly safe for the amateur gardener as long as the manufacturer’s instructions are adhered to. Maybe I don’t follow them quite as I should, particularly with regards to PPE, other than washing my hands. I am in my late 70’s and if I think back to the late 60’s and early 70’s when I used to spray God knows what on fruit trees from a cabless tractor without any form of PPE I think I am lucky to have made it this far! The most important thing is to stick to the manufacturers dilution rates. When using that which is available to the amateur gardener the recommended dilution is 24ml/litre. Commercial strength product at 360g/litre glyphosate is usually diluted at 20ml/litre for safe and effective use. There is actually nothing to gain from exceeding the manufacturers recommendations although some gardeners I have known in the past managed to get through remarkable amounts of product in a season!

No Dig

I use glyphosate as a tool in the garden. Although I was already familiar with its use in no-till agriculture in the US, I followed one man who was a great exponent of the use of herbicide to minimise cultivation of the soil in the UK. Roger Brook, a lecturer in Soil Science was a great advocate of controlling weeds by spraying therefore avoiding disturbing the ecosystem which he felt was detrimental to the soil’s health. His version of “no dig” was very different from today’s version which relies principally on mulching. A sign of the times occurred several years ago when a graveyard that he maintained and planted featured in a glossy magazine as a thing of beauty, strangely there was a distinct lack of further interest when it was realised that he had achieved this solely by judicious spraying of a herbicide. Even in my small garden, I still use spraying as my principle form of weed control.

No Dig may not be for you, it is very much a personal choice, but I hope that, in general, my experience is of interest, if in doubt engage the services of a qualified professional.

Glyphosate the Story to Date

To me glyphosate, now synonymous with RoundUp is the ultimate herbicide, its introduction in the 1970’s by Monsanto to be used with crops which had been genetically modified to be resistant to it, was a major breakthrough in weed control. Since the 70’s its use has diversified including on crops that have ripened unevenly so they can be harvested and as a major constituent of no-till agricultural practice. Although of prime importance to agriculture, it has been used successfully in the garden for many years until fairly recently when there have been claims that it is a carcinogenic and, as sure as night follows day, the litigation and subsequent bad publicity have followed.

Since 2018 there have been several high profile law suits in the United States against Monsanto, now a subsidiary of Bayer, because of an alleged cancer risk from the use of RoundUp and specifically its main ingredient glyphosate. The cancers in question are non-Hodgkin lymphoma and those related to it, and most allegations seemed to be based on a lack of warning on the product that it posed a cancer risk or even that the company deliberately withheld the fact. Although some studies suggest a link between glyphosate and non-Hodgkin lymphoma it has not been established and still remains open to debate. Even though Bayer offered up around $11billion to settle outstanding claims in 2020, there are still thousands that remain unresolved. Bayer has also removed its glyphosate from the amateur gardening market, but do not see this as admitting culpability as they still claim that it is safe and continue to supply the farming community.

Several countries in Europe have banned glyphosate for household use, including France, Holland and Belgium whilst Germany is moving toward restricting its use in public spaces and eventually a ban. Controversy arises from the fact that many agencies throughout the world back the findings of the EPA (Environmental Protection Agency) that glyphosate is an unlikely carcinogenic the primary dissenter, it would appear, is the International Agency for Research on Cancer which lists it as a probable human carcinogen. It must be noted that IARC is part of the WHO (World Health Organization) who in turn is an arm of of the UN (United Nations) and as such do not have the power to legislate in this case, although I am sure they would very much like to, this is the responsibility of the appropriate agency in each country or even state. Two major factors must be taken into consideration, firstly that the use of glyphosate is so widespread and such an integral part of modern farming methods it is currently impossible to replace it with anything remotely as effective, (see Rothamsted) and secondly, to prove or disprove the case is impossible simply because testing isn’t practical on human subjects and any results from animal testing would be purely conjecture, in effect it is a gigantic grey area. The saga roles on, Bayer trying to push for a Supreme Court judgement in their favour whilst handling yet more claims against them.

Despite there being no legislation in force, in the UK many supermarkets, garden centres and other retail outlets have removed RoundUp from their shelves in a mixture of independent and collective action but whether this is to appease their consciences or to appease the green lobby it is hard to tell, similar action having been taken with bagged peat.

On the other side of the coin in 2023 the EU has extended glyphosate’s licence for a further 10 years as member states reached a stalemate. In Brighton and Hove, always leaders when it comes to green initiatives, the banning of the use of glyphosate in 2019 and the decision to control the problem it has with weed growth on its pavements and roads manually has resulted in parts of the city looking “completely wild”. Glyphosate has been approved by the city council earlier this year for targeted use and with the exception of open spaces and play areas to get things back under control.

Next: Glyphosate in the Garden.