Just what are we spraying on our roadsides?

A true story in five short chapters

by Theresa Peluso

Parsnip

Ever since the news first surfaced last May that Lanark County was planning to conduct a trial roadside spraying a few weeks after they announced it, to assess the effectiveness of the herbicide ClearView in killing wild parsnip, there have been a lot of questions, facts and myths circulating wildly in the media and the community.

1. The (Supposed) Villain

Wild Parsnip!  the news headlines blared. It maims, blinds and kills people!  It kills livestock too!  Hogwash!  Apart from burns and blisters in some people, there is no verifiable evidence of anything worse.  The facts, unfortunately, don’t sell newspapers, but here they are.

Wild parsnip is a biennial plant.  That means its full life cycle lasts two years.  That’s all.  After that, the plant dies. It starts out as a rosette in the first year, only sending up the tall flowering spike (that strikes fear in all and sundry) in the second year. This plant seeds profusely, but those seeds don’t spread far, and they only sprout in disturbed soil.  For this reason, wild parsnip is rarely found in well-established fields.  And that’s why it’s commonly found on roadsides and along abandoned railbeds.  It also thrives in rich, alkaline soil, which is predominant in Lanark County.

The drawback with wild parsnip – which by the way, was imported to North America from Europe by the early settlers, and the seeds of which can be bought at a certain local hardware store by those who enjoy home-grown parsnips – is that its sap, if people come into contact with it, can cause a blistering rash – in some, not all, people – only if the skin is exposed to sunlight.  It’s one of many plants with this characteristic – such as limes, grapefruits, lemons and celery.  Does this mean you should toss your celery out?  Of course not! You eat the celery, and remember to wash your face and hands afterwards, before going out in the sun.  The chemical compounds in wild parsnip are known to reduce weight gain and fertility in livestock that eat it (and livestock know enough to avoid eating it in the first place), but there is no documented evidence of anything worse.

2. The (Supposed) Hero

But fear not!  We have ClearView to kill the evil wild parsnip, and once its mission is accomplished, everyone will live happily ever after!  Well, that’s wrong.  In fact, the (supposed) cure is worse than the disease.

This herbicide does not kill grasses, and that’s about all that can be said in its favour.  It kills nearly all broadleaf plants, including native plants, bushes, and any farm crops it comes into contact with. This includes all the flowering plants that provide a source of nectar for our pollinators, including parasitic insects that function as bio-controls for agricultural pests such as aphids, slugs, whiteflies and weevils.  ClearView has a predilection for killing leguminous plants, such as soybeans, alfalfa and clover.  Although this herbicide does not have an immediate effect on most humans and animals because it is not metabolized in the body, some individuals with multiple chemical sensitivity can become extremely ill when in the vicinity of sprayed sites, and there is no clear data on long-term effects to humans or animals.  In addition, because ClearView is not metabolized, the manure from animals that ingest ClearView, when spread on fields as fertilizer, will kill any crops planted there.

ClearView must, on no account, be used near water or during rainy weather because it takes many months to break down and, once it enters a wetland, pond, lake, stream or river, it destroys all the aquatic plants that grow there.  Since roadsides are, for the most part, ditches to catch the rain and snow which end up in our waterways, spraying them with this herbicide is a recipe for disaster.

3. A Reality Check

As it stands, Lanark County is touting herbicide spraying – with ClearView – as the easiest, most cost-effective solution.  If the County tries to take short-cuts to minimize cost, any roadside spraying will end up being both harmful and ineffective.  Listed below are several procedures that the County needs to follow, in keeping with the guidelines set out by the manufacturer and as specified in the Best Management Practices issued  by the Ontario Ministry of Agriculture, Food and Rural Affairs.

During the trial spraying that took place last May and June, the only public notification given by the County was announcements in the paper, which are easily overlooked.  Notification of individual affected landowners is required – what is the cost for that?

A detailed survey of wild parsnip infestations and the location of water bodies and water in ditches (often concealed by vegetation), as well as non-target plants, including trees, will need to be performed.  When you consider the hundreds of kilometres of county roads – what is the cost for that?

Any spraying will need to be timed to avoid windy weather (to prevent drift of the herbicide to agricultural crops and beehives) and wet or rainy weather.  Any contractor hired to spray may factor in lost time into the spraying quote – what is the cost for that?

Areas that are sprayed will leave LOTS of bare patches (remember, nearly ALL the broad-leafed plants will be killed), perfect for the wild parsnip seeds lying dormant in the soil to sprout and replace the dead plants.  These areas will need to be over-seeded with native plants – what is the cost for that?

It won’t be long before the sprayed weeds develop a resistance to ClearView, classified as a Group 4 herbicide, putting it in the same category as 2,4D, which is commonly used on farms. These weeds will then start proliferating among all the crops now sprayed with 2,4D, and take chemical warfare to a whole new level.  What is the cost for that?

Given all these concerns, isn’t using ClearView, and possibly more lethal herbicides such as TruVist (once ClearView loses its effectiveness), like playing with fire?

4. The Real (Environmentally Sustainable) Heroes

Because wild parsnip is a nuisance and has been added to Ontario’s list of noxious weeds, any infestations that create problems for farmers and other residents must be dealt with.  Really, there are far better alternatives to a blanket spraying program – more environmentally friendly and cost-effective ones. In lieu of chemicals, why not call on two tried-and-true heroes – human ingenuity and the trusty Bush Hog?

We need to conduct a detailed survey of infestations, using non-chemical strategies such as hand-pulling (wearing gloves, of course!), cutting, or tarping for small patches, The resulting bare patches then need to be overseeded with desirable plants.  For larger infestations, we need to mow the wild parsnip once only, but time the mowing just before the plant flowers or sets seed.  In the case of roadside mowing, which needs to be done anyway to preserve sightlines for traffic, no additional cost is incurred to remove the wild parsnip.

Should there be underlying rocks or especially wide expanses of wild parsnip (although Bush Hogs are available that can cut swaths of up to two metres), special attention may be needed to resolve the problem, but the additional cost is unlikely to come close to the cost for proper implementation of spraying, and the total environmental and health benefits of NOT spraying are self-evident.

We also need to make sure that residents are well informed about wild parsnip.  They should be able to identify it, know how to safely remove it without injury to themselves, and, if skin contact followed by sun exposure does occur, how to treat the lesions – just as is done with other noxious weeds, such as poison ivy.

Regardless of the approach taken to control the spread of wild parsnip, the fact remains that the County Weed Inspector can, as needed, act on complaints related to health, safety and threats to agricultural operations.

5. A Happy Ending?

With proper management, using environmentally sustainable solutions, we can control the spread of this plant.  Also, it could very well be that all this concern about wild parsnip is a tempest in a teapot.  Perhaps, if we just allow nature to take its course, while continuing to mow wild parsnip before it goes to seed, this invasion will subside, just as the purple loosestrife invasion did, not that long ago.  In fact, Lanark County also happens to be home to a potential nemesis for wild parsnip, the parsnip webworm. So – could the actual real hero be…the PARSNIP WEBWORM?

At this time, Lanark County Council has voted to proceed with spraying county roadsides, but individual municipalities have the choice to opt out of spraying.  Won’t you help to create a happy ending to this story by contacting your municipal councillors in the next short while, to request that they vote against spraying?