Organic vs. Inorganic (Chemical) Herbicides
Many people are rightfully concerned about impacts of inorganic (chemical) herbicides on the environment and the potential safety hazards of their applications.
The Summit County Noxious Weed Department decided to research the topic and also perform a field trial to determine the differences in effectiveness between the two herbicide types.
The month-long field trial was performed from June 26th to July 26th, 2017, in Summit County. The organic herbicide mixture was comprised of 4 cups household vinegar, 1/4 cup table salt, and 2 teaspoons dish soap. This mixture is a common recipe used by many people who wish to stay with organic herbicides. The inorganic (chemical) mixture was comprised 2 teaspoons Milestone herbicide, 2 teaspoons Induce surfactant, and 3 gallons water.
Photos of the both test plots prior to herbicide application showed several live and flourishing noxious weeds (chamomile and thistles). Two days after the herbicide application, the plants in "Organic Test Plot" appeared to be burned (brown and dead). The plants in the "Inorganic Test Plot" were nodding but were still green in color. One month after treatment, the plants in "Organic Test Plot" had completely recovered and some were even flowering. The plants in the "Inorganic Test Plot" were totally dead.
When researching it in more detail online, the Summit County Weed Department found that their results were not unique. Other studies also revealed that vinegar and salt (the most common organic mixture) only kills the top growth of the plant (the leaves), but it does nothing to the roots. It is also non-selective, meaning that it is likely to 'kill' any plant it touches (even the native species). Repeated applications of organic herbicide could change the pH of the soil, eventually making it uninhabitable for most species (good or bad). Treatments must be delayed for one to two days after rain; plants that are waxy or hairy may not absorb the vinegar; and organic herbicides may not be effective after two weeks of germination. Vinegar with a stronger concentration of acetic acid (11% or greater) is often referred to as Herbicidal Vinegar and can cause skin burns, severe eye irritation, and other irreversible bodily harm. Some states even require you to register with the state prior to using the higher concentration vinegar as an herbicide. Lastly, the Summit County Weed Department noted that organic herbicide tends to be corrosive on spraying equipment, and the equipment must be thoroughly cleaned after each use.
Inorganic (chemical) herbicides, on the other hand, will kill the whole plant, roots and all. Most, but not all, chemical herbicides are selective, meaning that they will only kill certain types of plants (not everything). Weather also has minimal impact on chemical herbicides as they are absorbed and translocated rapidly. Once the chemical is absorbed, in most cases, it is also safe for pets, livestock, and wildlife to touch and even eat. Chemical herbicides are not as corrosive and may be left in the sprayer between sprayings. That being said, sprayers should be thoroughly cleaned before switching to a different herbicide and before being put away for the season.