This tree-like brassica comes from the Mediterranean and the Middle East and traveled to Italy via the Eastern Mediterranean, where it then became popular with the Romans. According to folklore, Drusus Julius Caesar, son of the Roman emperor Tiberius, was somewhat obsessed with broccoli and, at one point, ate little else for the period of an entire month.
Despite the Roman enthusiasm for broccoli, similar sentiments for the crunchy crucifer did not initially extend to American shores. Although Thomas Jefferson experimented with broccoli cultivation at Monticello, widespread interest in the plant didn’t emerge until the 20th century.
Broccoli prefers a cool climate and likes well-drained soil with sufficient nitrogen (too much nitrogen can cause hollow stems). The recommended amount of nitrogen varies by location and time of year. Sun is good, but excessive heat encourages bolting; for this reason, partial shade can be beneficial but can also slow maturity.
Broccoli seeds can be started indoors about 6 to 8 weeks before your average last-frost date; transplant seedlings outdoors about 3 to 4 weeks before last frost. Sow your broccoli seeds 1/2-inch deep and cover lightly. If setting out seedlings, space them 16 to 18 inches apart. (Wider spacing allows for large central heads, while closer spacing creates small central heads.) Unlike cauliflower, broccoli produces side shoots after the main head is harvested, and you can continue enjoying these side shoots after harvesting the head.
About the Author: Samantha Johnson is the author of several books, including a forthcoming book on gardening for children. She raises purebred Welsh Mountain Ponies in northern Wisconsin.