Horticulture in the Movies: Interstellar

As winter approaches, there seems nothing better than to cuddle up on the couch and watch a movie. Watching movies is a favorite hobby of mine. And when movies mix horticulture into a plot, it gets my rapt attention. Toss in a little science fiction and you had me at the opening credits.

The thing is, there are not very many movies that have horticultural themes or subthemes. My goal is to find those movies and give my very own green thumb up or thumb down. I think taking Film History 101 qualifies me for such an endeavor.

Today we're going to feature the film Interstellar, a film by Christopher Nolan and starring Matthew McConaughey (Cooper), Anne Hathaway (Dr. Brand), and Jessica Chastain (Murph). This article is going to examine the plausibility of the science when it comes to the horticulture plotline. There shouldn't be spoilers ahead, as most of what involves horticulture in Interstellar is setting up the main storyline – finding a new planet for the human species.

The Setup

The beginning of the film introduces viewers to the primary antagonist- a blight that is killing off the world's food crops. Okra and corn are the last two vestige food crops for the human race and okra just bit the dust, with corn not too far behind.

Additionally, Michael Caine's character, physicist Professor Brand, reveals to Cooper the blight produces atmospheric nitrogen. As the pathogen population increases our breathable oxygen will decrease, therefore, "the last person to starve, will be the first to suffocate."

That is essentially the setup for the ensuing adventure undertaken by Cooper. But it raised some questions in my mind. Let's examine the plausibility of the horticulture science.

Can a plant disease, in this case, "the blight," wipe out all of our food crops?

The answer is definitive: no. At least in our present world. The first thing you learn in plant pathology is the disease triangle, where you must have the following conditions met for the disease to occur: 1) the pathogen itself must be present, 2) it must have the right environmental conditions, 3) and it needs a susceptible plant host. Even if the blight pathogen spreads around the globe, the diversity of Earth's environments and diversity of life's biology makes it highly unlikely any one disease will succeed on the entire planet.

To humans, plants are simply plants. We lump them all together, but there is an enormous amount of genetic diversity in the plant world. Saying a disease is going to affect all plants in this sense would be like saying a pathogen is going to wipe out all animals from aardvarks to zebrafish. Nature comprises an intricate web of life that can support large systems, even if strands of that web fail. It is our diversity which saves us.

However, there is one thing I take into account when considering the plot to Interstellar. We are in what some scientists call the Sixth Mass Extinction. Life on Earth has encountered five mass extinctions in the past 500 million years. Currently, a study published in "Science Advances" estimates the current extinction rate is 100 times higher than normal. (Ceballos, et. al., 2015)

How does extinction tie into the blight from the movie? Think back to what can save us in the disease triangle, diversity. As we lose species diversity, the web of life becomes sparser, making remaining plants and animals more susceptible to environmental and disease stress.

Perhaps in Interstellar many of the species on the planet have been wiped out not from the blight, but from the issues we face now – climate change, habitat loss, poor land management, and so on. The environment we are presented in the movie is one low in species diversity, which lacks the resilience to withstand something as simple as a plant disease. Though, it is still highly unlikely a devastating plant disease can jump from okra to corn.

I know, I know. You're shaking your head that I've thought way too much about this. And you're right.

Does leaving the planet solve their food crop problem?

I wasn't quite sure how evacuating the human species from the planet solves the original problem – the inability to grow food. If we assume the initial premise of the movie with the disease triangle in mind: 1) the pathogen is widespread on Earth, 2) it is successful in all environments, 3) and all food crops are susceptible, how can they grow these plants in space? The answer may be to create an artificial environment where the blight pathogen is not present in the first place. It seems it would be far easier to construct this artificial environment on Earth as opposed to a spaceship because your raw materials still need to come from the planet. I do understand building massive bubble cities on Earth doesn't fit the movie's theme of space exploration, and are more in keeping with film's like Logan's Run (1976) or Bio-Dome (1996).

Regarding horticultural science, Interstellar doesn't hold up. However, I still really enjoyed this movie. In fact, I've watched this film close to a dozen times, and each time I get completely sucked in.

Do you know of any movies with a horticultural theme or subtheme? I have a few more in mind for future articles but feel free to send me your suggestions. Hopefully, these movies may help you kill a couple of snow-bound hours this winter.