Corn (Zea mays) is easy to grow and easy to harvest; it is a nutritious and popular food. If you have the space in your survival garden, it is a good complement to other sources of protein and carbohydrate. I say, “if you have the space”, because you cannot grow just a few maize plants. The plant is pollinated by the wind, from pollen at the top of the plant, which then falls onto the silks of the ears of corn. You need at least 100 plants, grown in a block close together, in order to get good pollination. You can’t plant the seeds in one long row, or in one long double row. If the ears are not sufficiently pollinated, the cobs will be missing some kernels.
Maize does best with either ample rainfall or irrigation, and fertilizer. You can use compost, or an organic fertilizer, or just a good new-fashioned N-P-K fertilizer. Maize likes full sun and warm weather. Some varieties of maize are frost-tolerant, but most are not.
The range of different cultivars of maize is amazing. Corn varieties come in all colors and in multi-colors. Here is a graphic from Seed Savers Exchange and Mother Earth News showing different types of maize:
Historically, maize originated in South America. The earliest forms of maize, called ‘pod corn’ today, had a husk enclosing each kernel. Centuries of selective breeding of the plant gradually did away with this feature. Maize became an important staple food throughout South, Central, and North America. It was an important source of protein for Native Americans. Prior to the discovery of the Americas, Europeans did not know maize. Older texts using the term ‘corn’ simply meant grain in general (wheat, barley, rye, etc.), not maize.
Today, maize is the number one staple crop in the world, producing more total calories than any other food crop. In 2010, the world grew 844,405,181 metric tonnes of maize, which is 1,861,594,764,000 pounds. That is 1.86 trillion pounds of corn, not counting an additional 8,921,804 metric tonnes (19.7 billion pounds) of corn for fresh eating (e.g. corn on the cob, sweet corn kernels). In the U.S., 40% of the 2010 maize crop was used to make ethanol for fuel, and about another 40% was used for livestock feed. But elsewhere in the world, maize is grown primarily as a food crop.
Nutritionally, maize is a good source of carbs, a moderately good source of protein, and is low in fat. The protein in corn has all essential amino acids in ideal proportions, except that it is low in lysine. A diet using maize as a protein staple food must have a complementary protein that is high in lysine, like beans or other legumes. You can grow beans and maize together, so that the bean plants climb the corn stalks for support.
There is a relatively new type of corn, developed in the late 1980′s, but only now coming into widespread use, called Quality Protein Maize (QPM). This type of maize was bred to have higher protein content and a much higher proportion of lysine, while still retaining the palatability of more traditional types of corn. It is becoming a very popular crop in Africa and other developing nations. I have not yet found a seed source in the U.S.
At harvest, sweet varieties of corn can be used as corn on the cob, or be removed from the cob and eaten fresh as a side dish. Sweet corn has wrinkled kernels when dried. Dent corn has a small dent at the top of each kernel; it is low in sugar and high in starch. Flint corn is also high in starch, but has a lower moisture content and a harder kernel. Some varieties of flint corn are able to withstand hard frosts. Both dent and flint corn are used to make cornmeal or corn flour. If you have a large enough garden, maize is a good summer crop to grow.