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Good Growing

The Dark Side of Nature: Natural does not equal safe

Nature wants to kill you. Okay maybe wants is a strong word. Nature is term we give to the physical things and relationships that make up our world and universe. Sometimes we try to humanize nature with the name Mother Nature. We picture the ethereal Gaia sitting atop the trees directing the course of life on the planet. Such notions paint a serene setting, peaceful, and safe, which makes it so easy to market the idea "If it is natural, then it is safe."

Perhaps I'm jaded as an Extension horticulture educator. Often I see the other side of nature when things don't go as intended. I understand that nature is about struggle, natural selection, and evolving to overcome the challenges posed by our dynamic world. And yes, I come upon lots of plants and natural chemicals that can harm humans. It's not all butterflies and rosemary.

Throughout history, humans have been able to identify many natural chemicals to use for both good and evil. Let's take arsenic as an example. Arsenic is an organic chemical and was used as a pesticide for years. It was very good at killing pests. Arsenic is also very good at killing humans.

Poison hemlock is an example of a beautiful plant, found throughout the world, even along our roadsides in the Midwest. Poison hemlock is a plant with a dangerous secret because this plant's sap is toxic if ingested. Ancient Greeks used this plant to execute prisoners. Remember Socrates?

Another common Midwest weed, wild parsnip's sap causes burning blisters when exposed to UV light. A few years ago local roadside workers were weed eating a ditch without shirts when they unknowingly trimmed down a patch of wild parsnip. The string trimmers flung plant parts containing the sap all over them. Later that day their torsos were covered in blisters, which required treatment at the hospital.

Tree of Heaven is an invasive species whose sap can cause cardiac and lung problems. Conservationists doing their part to rid a natural area of this invasive plant sent their tree of heaven trimmings through a wood chipper. Nearly all had to be hospitalized as the chipper shredded the wood and sprayed the sap into the air, which they breathed.

I could continue and fill pages and pages on dangerous natural compounds, but the point of this article is not to scare you or be anti-nature. The purpose of this article is to build an awareness of blanket statements. "If it is natural then it is safe" is a blanket statement that lumps all organic chemicals into a category of safety. This topic is debated fiercely when it comes to the use of pesticides. My next article in the coming weeks will dive into organic vs. synthetic and ways we can select the lowest risk pesticides to protect the environment and us.

All living things on this planet have evolved defense strategies to keep from being eaten and perpetuate their genes. Sometimes these defenses are chemicals that are useful to us for controlling pests, but may also be toxic to humans. Just because something is from nature doesn't mean it is safe or that it is inherently good or evil.

Nature is wondrous and brings us peace. Gaia doesn't have a secret agenda against humans, but can be deadly all the same and deserves our respect.