Science behind gardening

Gardening is one of the earliest divisions of science but it is not normally thought of in that light. Ethnography of the People of the Plains is a previous course I have taken where I learnt that for many of our early ancestors, who were not hunters and gatherers, success in sedentary farming was key to survival. I also learnt that the First Nations Peoples of North America consisted of groups that often combined both hunting and gathering with sedentary farming. The most common crops of the sedentary farmers were corn, beans, and squash, which were also referred to as the Three Sisters as they grew better together than separately.  Three Sister planting is still practiced today in small scale vegetable gardening.

If you are asking yourself what a history lesson has to do with Unearthing Science I have your answer. The historical relationship demonstrated by the Three Sisters is an excellent example of the biological concept referred to as mutualism. The Three Sisters act together to enhance the growth rate and survival of each other. Digging deeper into the relationship between the Three Sisters I found that the corn acts as a support structure for the beans, the beans act as a nitrogen fixer in the soil, and the squash acts as mulch for the soil. All three plants help to improve soil fertility, unlike monoculture farming that usually degrades the soil.

Another benefit of planting corn, beans, and squash is that at the end of the growing season or at the beginning of spring the following year the left over plant material can be turned over in the soil providing organic material that acts as compost and mulch for next year's crop.

Also, the Three Sisters were grown together because they supplied a well balanced diet to the farmers and the members of their community. The beans provide protein, the corn provides carbohydrates, and the squash provides vitamins that the corn and beans lack.

Future Corn, Bean, Squash Plot. Photo by: Holly Harley

My plan for this summer is to experiment with growing corn, beans, and squash in my own backyard. Normally Calgary does not have the correct climate to grow corn but science has intervened with the production of a hybrid corn; the hybrid corn I am using is called Canadian Early Supersweet Hybrid F1. This hybrid has a relatively short growing season of only 65-70 days, compared to other types of corn such as Double Standard Organic corn which has a growing season of approximately 80 days. A short growing season is needed for Calgary because our summer is often very short with a limited number of growing degree days.

Gardeners are constantly using artificial selection  to produce plants with the gardener's desired traits. It is unclear how the Canadian Early Supersweet Hybrid F1 was developed but I'm assuming the technique is an industry secret so we may never know. What I do know is that a F1 generation is the first generation of offspring produced by two select parents. In Genetics, F1 generations are often used to determine the genotype of the parents if it is unknown. However, for the McKenzie seed company the F1 generation is not being used to determine parental genotypes but is being used for gardening as it has the desired trait of a shorter growing season.

By the end of the summer I hope to have a lush vegetable garden  consisting of the Three Sisters. Stay tuned for updates on how the Three Sisters are growing!
Happy spring plantings everyone!