Do you remember the TV show The Incredible Hulk? It was a weekly series about a muscle-bound guy who would suddenly completely change into some sort of a green monster.

As the narrative stated in the show, a strange metamorphosis occurs that transforms this man into the incredible hulk. It seems weeds are like that.

This past week I was cleaning the greenhouse to get it ready for the spring season and discovered some interesting finds, that quite frankly, I can’t believe are possible.

To fully explain this, I have to first provide some background.

We are completely done in the greenhouse by the end of May, so it’s largely left alone other than completely closing it up in July and August to essentially sterilize it and push out insects and vermin.

That’s done totally by design and I often make light of the fact that on a hot, sunny day in July or August, the temperature has reached 165 degrees Fahrenheit. That’s hot enough to fry a hamburger.

But weeds will survive in that environment. How is that even possible?
As I mentioned, we’re done at the end of May, so from that point forward, there is no longer water in the greenhouse so everything dries up completely. But the weeds keep growing.

Having been a gardener the past 19 years, I understand that weeds can have a deep root system, so they can draw moisture from much deeper in the soil than say an onion or a tomato plant.

But the plants themselves seem to not only grow, but thrive in some cases. Field bindweed, affectionately known as creeping jenny, is a good example.

How can it survive 165 degrees? I’ve stepped into the greenhouse at that temperature just to experience it and I have to tell you that it hurts just to breath. And I’ve never been in there longer than 20 seconds.

So you can imagine how that would drive mice out and when you look on the empty shelves, there are dead flies all over the place because they perish in the intense heat. Nor can spiders, mold or other fungus overcome that obstacle.
Twenty seconds isn’t long, and it’s unbearable to the human body. Those weeds are sitting there in the same position the entire day. Anything else would most likely bake before your eyes.

These weeds are super resistant to this heat and dry condition. It just baffles me that they can overcome this and I was reminded of that again last week when I cleaned all the dead weeds out of the greenhouse.
It’s a good thing they can’t survive the winter and finally die off. But again, in many of those cases, they will survive down to 28 and sometimes 25 degrees. It’s just bizarre.

On Aug. 16, 2021, we reached 106 degrees outside and yes, it was 165 in the greenhouse. The reason I remember it so well is because I had to pick produce that day for the CSA. The most striking thing I recall about that day was watching a 280-foot row of bell peppers just wilt before my eyes. And those peppers were in the open air.

Yet, some of the weeds inside the greenhouse didn’t flinch, while I could see some wilting in others, depending on the leaf structure.

Are there any plant scientists who can explain how weeds are able to flourish in an environment that is considerably harsher than Death Valley? Are there any explanations other than the deeper root system?
I’d like to know because I didn’t think there were too many things that would surprise me at my age. But this one is completely baffling.

I should also point out that the entire floor in that greenhouse is black to absorb the heat from the sun in the early spring. That makes ground level just as intense.