Week 17: The botanical roots of seasonal food

As you may know from trivia night, many of the "vegetables" we eat are actually fruits. A fruit, botanically speaking, is a seed-bearing structure from a flowering plant--such as a tomato, pepper, eggplant, or squash. Vegetables are all other plant parts, such as roots (carrots), leaves (salads), or flower parts (broccoli). Well, then there's tubers (potatoes), which are neither roots nor fruits, though they do generate new plants... but we'll leave that to another day.

To grow the fruit we eat, these plants must first grow a plant, then flowers, and then finally the food. This is a lot of effort for a plant, and plants that reproduce this way grow primarily in the summer when there is a long period of high-energy growing conditions. In the cool fall, with their seed-producing work complete, the warm-season fruiting crops slow way down. Our work turns towards the true vegetables.

We don't need to wait for vegetables to grow a fruit, since we'll just consume the plant itself. Moreover, unlike the summer crops, these plants (think spinach and kale) LIKE to grow in the cool fall weather and don't mind that there is no time to grow a fruit. They are simply aiming to get a head start on spring by producing a plant this fall before hunkering down for the winter. In March, when the weather warms, they will send up a seed stalk straight away before the competition even has a chance to germinate. And those beets, turnips, carrots? That's where the plant stores its energy for the long winter, to send up new shoots in spring. All these root crops and tuber crops are traditional fall foods because that is the time when the plants are stockpiling energy for spring. And the storage crops like carrots, beets, and potatoes are our traditional winter food since they store well through the winter when outdoor plants are frozen and dead -- precisely why the plants create those storage roots in the first place.