July 24, 2011

Corn is a Grass...

as are wheat, rye, oats, rice, barley. It is difficult to look at a large field of tall growing corn and relate it to the grasses we see growing around us. It appears that the origins of agriculture date back to around 10,000 BCE or before, when wild grasses began to be cultivated.

left,Teosinte; right, Maize, center, Maize-teosinte hybrid;
from Wikimedia Commons, by John Doebley

Corn, or maize, is a new world crop from Mesoamerica , and its domestication may have begun as long as 7,500-12,000 years ago. One of the theories of its beginnings has it coming from teosinte, a small annual grass, or a mixture of teosinte and wild maize. A few years ago I read a book on the beginnings of agriculture by Bruce Smith, and I remember being so surprised at seeing the tiny size of the wild ear of corn, which like other grains was selected over centuries for larger size. By 1500 BCE maize was spreading throughout the Americas and it became a staple food over the next couple of thousand years.

The corn we grow now has been hybridized for various traits and there are worries about genetically engineered crops, and the overuse of corn for ethanol (I certainly worry). I find the hybrid corns much sweeter, so those are what I grow: 3 rows of an early corn and 3 of a mid-season. The tassels of the early corn have now emerged; they are the male flowers whose anthers, which you can see dangling, contain the pollen....

that will drop on the silks coming out of the ears; each silk is pollinated to produce one kernel of corn, so if you open an ear of corn that has blank spots it's because that kernel did not get pollinated. Corn is wind pollinated, so has to be planted in a large block, which doesn't work for many small gardens. Happily, my garden is large enough for this delicious vegetable, which is one of the great treats of summer, lightly boiled with a touch of butter...oh my!


  1. You are a wealth of information. I didn't know corn was a grass. I have seen grasses before that I thought looked like corn. Now I know I wasn't far off. Pass the butter...

  2. Who knew that it had to be planted in a big block? Have to say that one of the joys of summer in the Midwest is the fabulous landscape of cornfields. When I first moved to Wisconsin I loved to drive by a huge field where the farmer was testing lots of varieties and every stand would have a sign saying what kind was growing there. We've been eating great local corn this past week — with butter!

  3. Looking at the bright red photograph, you can definitely see where the term "maize pattern" comes from--as well as the color maize. What an interesting history--like Lisa, I never knew corn was a grass. I used to spend my childhood summers in Iowa where corn was both a quintessential metaphor and a most anticipated delight. Now I understand why!

  4. Interesting post: the way you frame corn's history. I can see some of it in the fields of people I work with high in the mountains of NW Guatemala. There you have some corn grown from seed passed down by "the ancestors" and some GMOs with all the attendant questions. I too have some Concern about Ethinol as high demand in the States has caused its price to rise in countries like Guatemala when people depend on it for survival.

  5. I grew up in Iowa, surrounded by corn. I love to see it -- it's a plant like no other. I like the story of Samuel de Champlain seeing the native peoples' maize growing along the lake when he first came here. (And what do you do about the raccoons?)

  6. Thanks for all the comments.
    Ms. Wis.: when I taught in South Dakota many years ago, I remember all those corn fields with the signs in front of them. One of my souvenirs from my time in the Midwest is a Dekalb corn sign, an ear of corn with red wings, which is still hanging in my shed.
    Corn ethanol, and any fuel from food crops, is a big mistake because it raises the price of food enormously. There are other crops, such as switchgrass, that would make better fuels.
    I have a couple of strands of electric fencing close to the ground to keep out the small critters. When the corn is about ripe I put some fresh bait––peanut butter in aluminum foil packets––on the fence to be sure not to have any interlopers. It works.