Weed Slayer

UPDATE: Since I wrote this in February of 2020, Weed Slayer has been banned by USDA Organic and Demeter Biodynamic® Certifications for containing prohibited ingredients and is now the subject of lawsuits.


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I can’t forget when I first saw the results after we applied a new organic herbicide based on clove oil and molasses called Weed Slayer. Put very simply; it worked too well. It worked like Roundup but smelled like allspice.

In the past, products that were approved to use on a certified organic farm never caused any worry about being too effective. Many barely worked at all. But those days are changing, and the effectiveness of organic vineyard applications is now quite impressive. I tend to worry if an organic product is almost as effective as the chemical options, as there may be something to worry about. Chaos theory is a real thing. There is always the chance that these newly approved organic products are good at one thing, but they are also doing damage in some way we never imagined. 

In the past, certified organic products always seemed to have friendly names...Regalia, Prevont, Clean, BioLink, and so on. Weed Slayer is not a nice name, but it certainly does what its name suggests. A natural plant-based herbicide derived from eugenol, an essential oil of clove, and molasses. How bad can that be? Theoretically, not at all, but you can’t help but worry. One thing for sure, if you apply it at the right time, it works.

Now Weed Slayer is on the fast track as the miracle weed control product for organic agriculture, I can’t but help to be concerned as there is so much we do not know when it comes to the living system of our soils. Everything we introduce is bound to have outcomes that we cannot predict - chaos theory. My concern is that a product that kills weeds (note that weeds are simply plants that grow where we do not want them) so effectively could be very well having an equally devastating impact on the fungi that make our soils live. I have no proof of this, but the microbiome of soil is a very delicate system that is easily disrupted. 

The question we should be asking is, what is so wrong with a few weeds? The solution is not Weed Slayer or finding something even better. The answer is learning to live with weeds. With proper farming, you no longer have weeds, just a cover crop that you have designed. No-till is the best form of weed control in a vineyard because you end up with no weeds. Once the plants surrounding your vines are there because you want them there - magically, the weeds are all gone. 

But nothing happens magically in agriculture. You have to work and plan over the years to achieve your goals. At Troon Vineyard, we are moving towards no-till as quickly as we can. The major impediment we face in moving to no-till is that our older blocks suffer from the Red Blotch virus. While there is yet no absolute proof of the vector that spreads this virus, the leading suspects are leafhoppers. Practicing a full no-till system in the infected blocks could encourage the leafhopper population. We need to take precautions not to spread the virus into our new blocks. So while aggressively working towards no-till in the newly planted blocks, we have to practice a modified approach in the existing blocks. That includes only tilling every other row and mowing. While working this hybrid system, Weed Slayer becomes a necessary evil, but certainly a far lesser evil than Roundup.

It just a few years, we will achieve our goal of no-till agriculture for the entire farm. In my view, the foundation of practicing biodynamics is the regeneration of the natural microbiome of your soils. No-till is the natural partner to biodynamic farming as few things are more disruptive to the mycorrhizal community in your soil than tillage. On top of that is carbon sequestration that no-till farms support. This alone is reason enough to transition your farm to no-till.

It is fascinating to watch how agricultural science is moving towards biodynamics, not away from it. Soil scientists are now focused on the microbiome. Articles on fungi are everywhere. Huge corporate farms profess to be practicing regenerative agriculture, though this is more lip service for marketing reasons. Wineries feel compelled to become “sustainably certified” so they can get a green-sounding logo on their label due to market pressures. The double impacts of academics and market pressure are forcing more-and-more producers to adopt greener methods. But this is not enough, and it is moving too slowly. You are not practicing regenerative agriculture unless you give up chemicals (Roundup being the most famous of these, there are many others), feed your soils via compost, and are working towards no-till. 

For us, using Weed Slayer is temporary. A means to achieve a larger goal. Even something that sounds as benign as clove oil and molasses, and is permitted under CCOF Organic certification, may have a negative effect on everything else that we have been working to achieve. It takes years to rebuild the mycorrhizal communities in your soil, and using anything that can disrupt that is a risk. I am very uncomfortable taking this risk, but the threat from the virus is also a reality. Finding the proper balance is a struggle. 

I am not picking on Weed Slayer here, it is a product produced by people trying to find a safe alternative to Roundup. Certainly, that is a worthwhile endeavor. My point is that all inputs can have unintended consequences. Less is more when it comes to farming. The fewer products we use the better.

Regenerative agriculture is not a goal you achieve, but an ongoing and never-ending process to work in harmony with nature. As we will never know all the secrets that nature is hiding from us, we can only strive to learn what the plants are trying so hard to tell us. We need to learn their language more than they need to learn ours.