Finance History | Hortus botanicus Leiden, 1594 — The Flower That Could Not Be Mass-Produced

The red flames on a white petal that made a tulip expensive were the symptom of a virus. Carolus Clusius took up his post at Leiden University in 1593 and planted bulbs in the university's new teaching garden and in his own ground late that year. The spring of 1594 is generally taken as the tulip's first flowering in the northern Netherlands, and the plant turned out to tolerate the wet cold of the Low Countries. What happened next was not only fashion. It was a supply constraint written into the plant. The prized broken tulips, feathered and flamed, owe their patterns to what is now called the tulip breaking virus, which splits one petal colour into two or more. The economist Peter Garber drew out the consequence that matters here: the same infection progressively impairs the bulb's production of daughter bulbs. So the most wanted tulips were the ones least able to multiply, and a grower who wanted more of a famous variety waited years for offsets. Seed was no shortcut, because a tulip grown from seed does not come true to its parent. Price could climb as fast as buyers wished. Supply could not follow it. The calendar finished the job. Bulbs can only be lifted and moved during the plant's dormant months, roughly June to September, so real delivery happened in that window and nowhere else in the year. For the other three quarters, there was nothing to hand over. Traders who wanted to deal in winter had to deal in promises instead: contracts signed before a notary to take delivery when the bulbs came out of the ground. That is a forward market, and it appeared here because of a flower's biology rather than any financier's design. The garden on this spot is a reconstruction of Clusius's own, a small rectangle of raised beds inside the Hortus botanicus. It sits behind the university's Academy building on the Rapenburg, and it is where the most quoted bubble in financial history actually starts. Photo: Gemeente Leiden / Jan Holvast, CC0, via Wikimedia Commons — the reconstructed Clusiustuin in 1990. Second image: an anonymous 17th-century watercolour of Semper Augustus, the most expensive tulip of the mania, showing the broken pattern the virus produced.