The Staple Crop to Vegetable Pipeline

Few people realise that many of our vegetable species have origins as staple crops. For example snow-peas are merely specialised lineage of field peas, which were cultivated for millennia as a staple dry legume (for dishes such as peas porridge mentioned in the old nursery rhyme). The creation of snap beans from kidney beans and sweet corn from more vigorous maize populations mirrors this pattern. This general pattern of harvesting a plant in its tender, immature stage of development extends to solidly staple crops like wheat (through the production of freekeh), and even to non-food crops in the form of immature bottle gourds and luffas.

The creation of dedicated vegetable type lines of staple crops often leads to a loss of vigour, probably due to some combination of inbreeding and smaller scale cultivation permitting more resources to be invested in each plant. The loss of defence chemicals may also be necessary to allow fresh consumption.

Pumpkins were also originally a staple crop, grown for their oil and protein rich seeds. Their use as a vegetable was of minor importance, until the much more recent development of weaker strains bred for production of thickened, sweet flesh. Watermelons were likewise originally domesticated as a source of storable water during the dry season, then for their oil rich seeds, until a single mutation led to varieties with sweet flesh appeared relatively recently.

The next example showing the whole pipeline is the humble apple. In many places in Europe peasants would forage for wild crab apples growing in hedge rows and wild places. These sour fruits were added in small quantities to cooked food. Later came orchards of high tannin apple varieties, best suited for brewing into cider. These were often seed grown since variations in fruit quality were tolerable, while lack of vigour or productivity was not. Only much more recently did the idea of dessert fruit spread widely, relying on highly selected, grafted clones that produced high sugar/low acid fruit suitable for eating straight from the tree. This genetic narrowing brought an inevitable drop in vigour compared to previous incarnations of the genus.

An interesting variation on this process is the evolution of various plants from potent medicinal herbs, to culinary herbs used for flavouring, and eventually bland, bloated versions that are consumed in larger quantities as vegetables. Lettuce was originally grown for the latex in its flower heads, used as a mild sedative/pain killer. Carrots were also originally a diuretic, then an herb for its flavourful seeds and leaves (similar to coriander today, a species where the insubstantial root is also consumed). In time coriander could be selected for large, tasteless roots as well. Parsley has gone through a less widely known transformation, leading to hamburg strains with carrot-like roots.

If you are interested in growing your own food then this should give you a sense of perspective. Modern vegetable varieties represent some of the weakest, most inbred organisms on the face of the earth. They were developed to give maximal performance and profit under carefully controlled, high input conditions, with each species demanding a specific soil type and set of management practices.

Expecting to grow the range of vegetables that we typically buy in the supermarket in a home vegetable garden is an act of folly. Even if your soil isn’t necessarily “bad”, it is impractical to have the sandy soil beloved by carrots and the mineral rich clay beloved by broccoli at the same time. No commercial vegetable grower would be expected to produce both crops profitably on the same land. This process of specialisation/narrowing of genetics has only gotten worse in widely accessible vegetable genetics in the last century, with the majority of seed for sale to home gardeners coming as by-product from the sprawling industrial vegetable growing system (which now relies heavily on greenhouses, automated watering systems and integrated pest management).

All this stress and effort to grow a product which is little more than water and cellulose that carries a vague promise of “health”. Vegetables can be lovely, interesting and beneficial additions to the human diet, but history shows they have always been peripheral players in broader agroecological systems. Home growers would do better to take a step backwards, away from the most intensively vegetablised varieties.

It’s time home gardeners put vegetables in their proper place. To do so we need to focus on the ideal traits of a vegetable suitable for home scale production, something I hope to do soon in a follow up post.