It’s no secret my fondness for edible weeds or my complete disdain for Round Up. I hung a sign in the alleyway, “No Poison, Please. Edible Weeds Grow Here.” I’ve done my best to educate the poor, misguided landscapers and maintenance workers who spray Round Up on every little weed and even baby palm trees. (Won’t kill ’em anyway…) Sometimes I’m more successful than others. At a recent city council meeting, a woman took advantage of the public hearing period to urge the council to stop weeds from coming up this monsoon season by spraying pre-emergent herbicide all over town. Right then and there I decided to use my time to speak up about it. But Mayor Rothschild, in his great wisdom, had me speak on my other issue instead. That was just the nudge I needed to share my concerns with him and all the city council members in great detail… including links. lol
Feel free to write your Council Member too!
Dear Mayor Jonathon Rothschild and Council Members:
I’ve been meaning to speak up at a city council meeting about the transportation department’s overuse of herbicides for some time. After my mom got a severe headache from breathing in the Round Up sprayed in a right of way on our street, I spoke to the landscaper about it. He replied, “The city sprays it everywhere, so can we.”
Since then I have been very aware of herbicides sprayed on city property. The other day I was stunned to see an entire lot covered with it. Recently I walked by the County Public Service Center building. In the catchment basins – that should be an example of the best water-harvesting practices – there were turquoise patches of weed killer. Right where the rainwater sinks in to restore our aquifer! I brought this up to t
Department of Environmental Quality just to be told that was the work of the city maintenance department.
I am writing today because I was disturbed by a comment I heard at last night’s meeting. A woman claiming to be from the “landscape advisory committee” suggested that monsoon season was upon us so the city should spray pre-emergent weed killer everywhere to keep the weeds from coming up.
I have several problems with that. First, it won’t keep the weeds from coming up. We have used so much that the weeds have grown resistant to it, so we need more and more to kill any. Weeds will come up after the monsoon rains anyway. By spraying them with herbicide before the monsoon rains, the poison will just run into our yards, playgrounds and those catchment basins (that are meant to sink the water into our ground water). The post-emergent herbicide, glyphosate, has been proven to cause cancer: https://www.scientificamerican.com/article/widely-used-herbicide-linked-to-cancer/. However, there are also concerns about preemergent herbicides. It was once thought that herbicide contamination would be mitigated through filtration, but the active ingredients have been found in our ground water: https://water.usgs.gov/edu/groundwater-contaminants.html.
Roundup is a postemergent herbicide sprayed on weeds and grasses that have already sprouted. That has nothing to do with preemergent herbicides that are intended to keep weeds from sprouting in the first place. Observing the practice of landscapers and maintenance people around town, they frequently are misapplying Roundup as a preemergent. But preemergent herbicides have a number of issues. One is that any one chemical is only effective on a small subset of weeds, so multiple herbicides have to be sprayed to kill all of the “undesirable weeds.” They also just don’t work on some of the most noxious invasives, like buffel grass. The other problem is that the application period is very specific in order to kill the seeds when they are germinating. Not all landscapers are going to apply them at the right time to have any effect. Plus, they need to be watered after application to sink the chemicals into the soil. How many right of way sprayings are being watered immediately afterwards. They also shouldn’t be used in a landscape with organic mulches because they will bind to the organic mulch and affect the growth of desirable plants. And, of course, just like the postemergents, they also contaminate the soil and the groundwater. Diuron, one of the pre-emergent herbicides recommended for use by the Arizona Department of Transportation has been shown to be toxic to birds, wildlife, and aquatic life and – even worse – one of the biproducts of the breakdown of diuron in the environment is the production of an even more toxic chemical, which stays in the soil and can contaminate groundwater. The European Union has banned its use, but of course it’s still being recommended for use in the US.*
I’ve done my own monitoring on the effectiveness of herbicides on weeds. Every day, I walk by that house where the landscapers insist on spraying every little weed (and sometimes the whole yard) with industrial strength Round Up. I’ve observed that the herbicide works temporarily on the tiniest weeds, but even more weeds pop up by the next month – which get sprayed too. So it’s a never ending cycle of toxic weed killers in our neighborhood. Just wait a week or so for the weeds to die in the desert sun! Herbicides have no effect on Bermuda grass (which would take a bulldozer to get out the whole root system) ow bigger weeds.
We need to rethink what we consider acceptable desert landscaping. The plastic and gravel we use to keep weeds out of the yard also keeps rainwater from sinking in to restore our ground water. Many so-called weeds are planted in road side basins to help the water sink into the ground and prevent erosion. The native grass works with the mulch to create a sponge to soak in the monsoon rains.
We need to reconsider what we call “weeds.” Many Tucsonans glean amaranth, lambsquarter, desert mustard and purslane (in Spanish, Verdolagas), my personal favorite. I’ve heard of preschool teachers taking their students on neighborhood walks and having them taste edible weeds. We certainly don’t want to poison children foraging at our neighborhood parks!
Please, look into the effect of herbicides on the public health and the cost of repeated use. Then ask the maintenance department to stop spraying that ineffective weed killer all over town.
Sustainable Tucson Core Team
*Updated response added after e-mail to Mayor and City Council.