Of Joe-Pye and Dunning-Kruger

When I first started to volunteer at the Waters garden I was afraid of weeding. To be honest, I still am. What if I pull the wrong plant? Think that I’m helping only to discover that I pulled the rarest, most valuable plant in the garden. So I made sure that I learned the species to pull one by one. First creeping charlie, an invasive species that is pretty easy to recognize, if not so easy to eradicate. Then came Joe-Pye, I carried a specimen with me as I worked to compare with what I was about to pull, so that I could be sure that I pulled the right thing. Joe-Pye weed is pretty easy to recognize too, so I quickly became confident. Perhaps too confident; at garden night, when other tasks ran out, I could look for the plants on my weed list and pull them, safe in the knowledge that these were plants that should be removed. I taught others how to recognize them so they could pull them with me.

Then I discovered that Joe-Pye is a native plant. I questioned, why remove a native? Well, it gets tall, crowds out other plants. Pulling it helps the more ‘valuable’ plants by giving them more space and light. This satisfied me for a bit, but as I watched the work in the garden it began to dawn on me that there was more to it. The question was not so much what to pull, but where and when to pull it.

Native ecosystems evolved over epochs that are difficult to comprehend. Different species competing for the same resources gradually establish an equilibrium, some even come to rely on one another. Different plants flower at different times in the year to reduce competition for the pollinator insects; species like the oak trees have mast years, where all the trees synchronously produce so many acorns that the animals that eat them are overwhelmed and can’t consume them all. When humans first arrived in the Chicago region, they disturbed this equilibrium. Some species were driven to extinction, but over time a new equilibrium emerged. The humans, plants and animals of this area lived in a balance with one another.

Then came the modern world. Natural areas were suddenly considered to be ‘unimproved land’ just waiting to be torn up and exploited. The delicate equilibriums built over thousands of years were destroyed. Some species seized their moment. Tall goldenrod and others sprung up wherever disturbed land was left unmanaged. But others became rare and precious.

When we try to restore native ecosystems we are trying to achieve in a few years something that would only occur naturally over thousands. The plants and animals have not evolved to deal with this kind of environment, thousands of years of battles are re-played in our gardens. For a restoration to be successful it needs a watchful eye. Someone to say, “the rosin weed are taking over that section of the garden, let’s thin them out before they go to seed”. Someone who understands how to guide the plants towards that equilibrium in this new environment. 

I don’t know how to do this. Maybe one day I will; but a couple of years ago I didn’t even know that I didn’t know this. This is the Dunning–Kruger effect. People with limited knowledge of a subject tend to overestimate their competence; it is only as you learn more that you learn how much there is still to know. Knowing that this can happen is key to seeking knowledge with humility and applying that knowledge with precision. It is the value that experts bring to the table; not just because they can speak with the authority of years of learning, but because they can foster this humility, having stumbled on the same pitfalls themselves.

Joe-Pye is a beautiful plant. I know now that it has an important place in the garden, that we should not indiscriminately pull every example we see. Sometimes it grows to excess, gets too tall, crowds out other plants. Then an experienced eye will see where and when it needs to be removed. For me, I will be happy when I can tell the two Joe-Pye species that grow in the garden apart.

Jeremy Atherton, Waters Parent