Father of Invasion

We could remember ­Phillip Franz von Siebold as an adventurer, the father of the first female doctor in Japan, and an advocate for public health. He would probably have preferred it that way and that’s certainly the article I could be writing, had he not plucked a single specimen of Japanese knotweed (Fallopia japonica) from the side of a volcano in Japan and began distributing it commercially in the Netherlands. By 1850, samples of this graceful, bamboo-like plant had been included in the Royal Botanic Gardens in Kew, England. And now here we are, with knotweed representing as one of the most prevalent invasive species in the world, appearing throughout East Asia, Europe, Canada, the United States, Australia and New Zealand, lowering property values in Britain, and stymying all efforts at permanent eradication. Sorry Phillip, but you made choices and now we are living with the consequences of them.


Siebold was born on February 17, 1796 in Germany. Like many of his era and interests, he avidly read the works of Alexander von Humboldt. Humboldt was a pioneering explorer and thinker, he not only ventured into areas considered the darker recesses of the Earth, he accurately and poetically described what he found, then drew parallels to a more familiar world. Humboldt saw connections and relationships, where others saw exotic and novel. His work became the basis of ecology, the study of those relationships that web the abiotic and biotic face of this planet. While many in Europe sat content in their armchairs reading Humboldt’s work, Phillip von Siebold felt a stronger pull toward both botany and adventure. He studied medicine in Germany, then traveled to Japan with the Dutch military in 1823.


Once in Japan, Siebold was posted in Deijima, Nagasaki, as the resident physician and scientist. Japan was notoriously secretive and closed to outsiders at that time, but Siebold was given permission to leave the trading post and treat people in the greater area after successfully healing a senior officer. While in Deijima, he introduced vaccination and other aspects of Western medicine, work that could tip the scale of being a problem solver versus a problem creator more in his favor overall. While pursuing improved health outcomes for the citizens of Deijima, he pursued his own hobbies as well, starting a small botanical garden and glasshouse where he cultivated over 1,000 species of plants native to Japan. One of those plants was, of course, Japanese knotweed.


Even though the locals appreciated him, the Dutch did not and attempted to recall him in 1827. A typhoon damaged the ship that was to take him home, which was eventually repaired and sailed away…without Siebold. His plant specimens were on board, however, and reached European shores that same year, finding their ways to collectors in Belgium and the Netherlands. In 1829, the Japanese kicked him out for the possession of maps of Japan and Korea, which the Japanese government had strictly forbidden.


Back in Europe, Siebold settled in Leiden in 1830. He retrieved the plant specimens he had sent to Antwerp, Ghent, and Brussels and began cultivating what would become the largest and earliest collection of Japanese plants outside of Japan. Siebold eventually made knotweed commercially available in Europe, which was awarded a gold medal in 1847 by the Society of Agriculture and Horticulture at Utrecht for being the most interesting ornamental plant of the year. Siebold’s pricing structure may have been an early clue to knotweed’s tenacity in Siebold’s own nursery—plants were sold in quantities of 100. The catalog description of the plant highlights its use for stabilizing sand dunes, providing fodder for cattle, medicinal properties, flowers for use in bouquets, edible young stems, dead stems that could be used to make matches…and it’s near-total inability to be extirpated. Gardeners loved the plant for all these uses and several influential gardening professionals wrote about knotweed’s usefulness and grace in British gardens.


Siebold spent the latter years of his life writing about the flora of Japan, advising the military about the country, and trying to find a way back in. His banishment was lifted by the Japanese government in 1858 and he traveled there the following year. The Dutch removed him once again in 1861 for violating the terms of their agreement with him (i.e. they told him not to get involved in Japanese politics but he got involved in Japanese politics). Siebold spent the rest of his life trying to convince various countries to send him back to Japan, none of which took him up on the offer. He died in Munich in 1866. Visitors to his gardens in Leiden in 1883 noted that they had fallen into disrepair, totally overrun by knotweed.


Let’s take a moment to think about the moments that led up to the massive amounts of knotweed spreading around the globe today. First of all, a German doctor had to be interested in botany and the Far East (What if he had been interested in insects instead? Or longed to see South American, as Humboldt had done?). Then he had to catch the eye of some higher-ups who recognized his potential (What if he hadn’t been very good at his job?). He had to meet a sick officer in Japan, whose ailment happened to be something he could successfully treat with early-1800s era medicine (What if had been something incurable? What if the officer had died from his illness?). He had to have time, interest, and ability to wander around the Japanese countryside (What if he had broken an ankle climbing that volcano? What if he had forgotten to pack enough food and decided to call it a day?). His shipments of plants had to survive an overseas journey from Japan to Europe, then be cared for adequately until Siebold himself returned home (What if the ship had sunk? What if the shipments had been held up in port and dried out?). Siebold then had to cultivate and market knotweed commercially (What if Victorian gardening sensibilities had rejected knotweed’s aesthetic appearance?). A series of coincidences and choices have turned a plant growing in certain areas of a few countries into a global colonizer. What other invasions have been thwarted by a random series of events or a single person choosing to plant species A instead of B? In our globalized world, coincidence and choice both wreak havoc on ecosystems and save them simultaneously.