1: Broccoli
Welcome to the first entry in my new blog, which is all about different domesticated species. Each entry will cover a different domesticate, both plant and animal. This is a longstanding interest of mine but also might help me be better at home gardening - so let’s start with a new type of food crop I planted this year, broccoli.
First of all, where is broccoli grown? I love this chart from Our World in Data which allows you to select different foods and see where they grow. Broccoli is mainly grown in China, India, and the USA - with China and India being around an order of magnitude in pounds grown per year. Spain and Mexico also grow quite a bit.
As I’m sure you’re aware, broccoli is a member of the brassica family. I love this figure which shows the many types of food derived from brassica. Brassica oleracea, of which broccoli is the italica variant, includes such diverse foods as cauliflower, brussels sprouts, and kohlrabi. Like artichokes, what you eat of broccoli is the flower and stem - the leaves are bitter and rarely included in food.
Broccoli rabe, by the way, is a different type of brassica and actually more closely related to the turnip.
Broccoli is a landrace crop, meanwhile a locally adapted, traditional crop. The Etruscans in modern-day central and southern Italy likely grew the first varieties in the 6th century BCE and farmers in the Roman Empire continued to cultivate it. It remained popular in Italy for many centuries, known as broccoli, derived from Latin brachium, referring to its branching arms; when it came to England in the 18th century, Philip Miller's Gardener's Dictionary of 1724 described it as unknown and called it “Italian asparagus”. Thomas Jefferson experimented with broccoli seeds in the late 1700s, but it did not become a popular and well known food in North America until the late 19th/early 20th centuries, arriving with southern Italian immigrants.
Like many popular crops, industrial agriculture has dramatically transformed the broccoli that we see in supermarkets in the USA, especially after WWII - in short, they are grown much faster and much bigger than they were less than a hundred years ago, but the strains that most people eat are very closely genetically related and have reduced diversity. This interesting paper tracing broccoli genetic heritage summarizes:
“Although Calabrese broccoli was initially brought to the United States by immigrants from southern Italy, it only gained popularity there post-WWII, following development of improved open-pollinated cultivars such as ‘Waltham 29’ (1950) from the Massachusetts Experiment Station. Supported by American and Japanese breeding of commercially successful hybrids such as ‘Premium Crop’ (1975), ‘Packman’ (1983), and ‘Marathon’ (1985), production was shifted to the cooler valleys along the western U.S. coast allowing year-round production. These hybrid breeding efforts increased yield (head size and harvest index), horticultural quality, regional adaptation, while decreasing days to complete growing cycle39. China is now the largest producer of broccoli and Chinese cultivars appear to be derived from a core collection of Japanese germplasm, exhibiting close genetic relationships and reduced diversity.”
I suspect that this will be a common story as we go through the different domesticated plants - a post WWII expansion of growth and loss of diversity.
I drew one of the broccoli plants currently sprouting in my garden. Unfortunately I am not sure which variety of the plant I have. I’m very interested to see how it develops from here!