Fairfax Master Gardener Talks Montgomery County & Ontario,Canada Pesticide Ban Failures

Neighboring County Wages War on Lawns

By Gil Medeiros, Fairfax Master Gardener
I hope it doesn’t happen here in Fairfax County. I’m speaking of the Comprehensive Ban on the use of “cosmetic lawn pesticides” enacted recently by Montgomery County, Md. While reduction in the use of pesticides is a laudable goal, this is the not the way to do it.

The ban, patterned after one enacted by Takoma Park, Md., in 2013, will begin to take effect in 2017. It includes the following.

  • The Class 9 pesticide list from Ontario, Canada. This list contains 119 pesticides. The Ontario website says “Class 9 pesticides are banned for cosmetic purposes because they may (emphasis added by author) pose an unnecessary risk to human health, particularly children’s health.” One may infer from this language that the Canadians do not have a real handle on the level of risk posed by any of the chemicals under their blanket ban.
  • A list of chemicals that are deemed by the U.S. Environmental Protection Agency (EPA) to be carcinogenic to humans or likely carcinogenic to humans. By my count, this adds about 25 chemicals to the ban; none of these are commonly used on lawns. (Data from EPA’s Integrated Risk Information System database, advanced search for carcinogenic or likely to be carcinogenic to humans)
  • The European Commission’s list of 66 endocrine disruptors. Very few of these are used on lawns, or in gardens for that matter. The fungicides maneb, zineb and thiram are on the commission’s list. Zineb and Thiram are also on the Ontario list.
  • The EPA’s list of Restricted Use Pesticides (RUP). This list covers more than 1,000 products that cannot be purchased without a license. Products often make the RUP list because the formulations are concentrated and pose a handling hazard to untrained members of the general public. The RUP list is by product name; the Ontario list is by active ingredient. A simple cross check reveals that the vast majority of products on the RUP list contain active ingredients already banned by the Ontario list.

Good luck to you, the lawn owners in Montgomery County. As a result of this ban, you will no longer be able to control broadleaf weeds in your lawns because selective lawn herbicides such as 2, 4 D, dicamba, MCCP, and triclopyr are included. Crabgrass? Get ready to do a lot of hand-pulling because the pre-emergent crabgrass killer dithiopyr will be gone. Yes, the organic alternative, corn gluten meal, is approved for use as a pre-emergent. The trouble is, it doesn’t work very well in our Middle Atlantic climate, according to research conducted by the Virginia Cooperative Extension.

If you have a problem with fungal diseases, you will have to determine a cultural method to prevent them because propiconazole, myclobutanil, thiophanate methyl and azoxystrobin are all banned. Do you have grubs in your lawn? You better hope that beneficial nematodes can control them because you will no longer be able to use imidacloprid. Is the weed Nimblewill taking over your lawn? Live with it because mesotrione is included in the ban. If you want to kill everything and start over again, you will have to do it without glyphosate (the active ingredient in Round-Up).

The ban has inconsistencies that raise questions about the diligence of Montgomery County’s research. Among the 119 chemicals on the Ontario Class 9 list are spinosad and pyrethrins, which are insecticides not commonly used on lawns but approved as organic for food crops and ornamentals by many regulating agencies. Also, azoxystrobin is on the list. It is a very effective fungicide used on both lawn and food crops. Toxicology reports I have read refer to the risk to human health and the environment as extremely low. On the same list is diazinon, which is a serious poison not currently approved by EPA for use on residential lawns. Perhaps, Montgomery County is banning it in case EPA changes its mind. The Canadians–and, by extension, the Montgomery County Council–left off a few commonly used cosmetic lawn chemicals: pendimethalin, a widely used pre-emergent lawn weed killer, and quinclorac, a widely used post-emergent used to control crabgrass. Since the ban is intended to be comprehensive, I have no explanation except that this must have been an oversight.

So what is wrong with this?

  • Brown Patch

    The ban eschews the sensible risk-management approach adopted by the Environmental Protection Agency and every state in the U.S.A. including Maryland, and replaces it with a complete risk-aversion approach. The ban cites no relevant health standard for banning chemical pesticides on lawns. It references studies of unknown validity. It bans high-risk pesticides and low-risk pesticides as if they were all the same. It invokes a looming health threat without saying what it is. If it is a chemical pesticide, says Montgomery County, and it is used to improve the appearance of a lawn, we are banning it–evidently, because the Canadians do.

    Even when a lawn is well maintained, a turf disease such as brown patch can strike. Homeowners in Montgomery County will have no chemical remedy for turf diseases after 2017.

  • The appearance and health of the lawn are intertwined. In Montgomery County your alternative to a chronic insect or disease problem will be to grow new grass and wait for the same chronic problem to reappear next year. Cultural practices will take you only so far in addressing insect and disease problems. You will not be able to address the cause by using a pesticide, and so you will see the problem over and over again.
  • The law’s sponsor claims the bill was the result of careful reading of scientific literature on hazards. The fact that redundant banned chemical lists generated outside Montgomery County were incorporated in the law without exception belies this claim. Did anyone really read those lists, much less understand them? There is a claim by the sponsor that people in Montgomery County are more educated than most and know better when it is time to end inherently dangerous practices. Surely, some of those well-educated citizens, which include many highly respected physicians and scientists, could have come up with their own list that reduces the use of some chemicals but allows others. This would give the lawn owner a fighting chance of solving some problems. Instead, Montgomery County simply copied the know-nothing-approach adopted by Takoma Park. An action of this importance by a major unit of government warrants detailed study prior to its adoption, not the use of a convenient shortcut.
  • Many of the same chemicals that Montgomery County has banned for use on lawns are commonly used by farmers to produce the food we eat. Yes, we are all ingesting some of these banned chemicals in very tiny quantities that are judged to be safe by the EPA. Does it make sense to create a big stir about chemicals applied to the lawn when the same chemicals are ubiquitous in agriculture? Montgomery County has moved not an inch to solve that problem, if it is one. In Montgomery County you will be prohibited from spreading chemical pesticides on your lawn, but you will be able to use them without restriction on your beans and tomatoes.

I am not a lawn nut. I have reduced my lawn considerably over the years in favor of annual and perennial beds. I am a sparing user of lawn chemicals. I tolerate some weeds and disease in the lawn; it does not have to be perfect. It is difficult to grow a lawn here in the Middle Atlantic. I know from experience that conditions of too much rain, too much heat and humidity, random insect infestations and other things beyond my control can produce disaster in the lawn in spite of my care. It sure helps to have the option to use chemicals occasionally to address difficult situations.

I would not appreciate being told by the local government that the chemical option is no longer available. I especially don’t want the prohibition to come from officials who do not seem to understand the problem they are trying to address or the solution they are determined to pursue. They have rendered a verdict on evidence that is thin at best and nonexistent at worst. Yet these officials have asserted their judgement is superior to that of experts at the U. S. Environmental Protection Agency and the regulators of the state of Maryland.

Have Montgomery County officials struck a great blow for environmental protection, or have they made an environmental grandstand play that will be more trouble than it is worth to local citizens? Signs point to the latter.

Section 5-8, WeedsVirginia Pest Management Guide, 2015
Potential Health Effects of Azoxystrobin in the Environment, Von Stackelberg, 2012, E Risk Sciences LLP
Diazinon, General Fact Sheet, National Pesticide Information Center

The preceding is the opinion of the author. It does not represent the position of the Fairfax County Master Gardeners Association or the views of its members. FairfaxGardening.org welcomes differing opinions. Please send your thoughts to editor@FairfaxGardening.org.

Source: Pesticide Ban