Visitors who stroll through the CAU's Botanical Garden can marvel at plants from distant climate zones. A diversity of species made possible by a global seed exchange.
Four years after the founding of Kiel University, Professor Johann Daniel Major could finally dig his spade into the soil of Kiel’s Schloßgarten in 1669. 10,000 square meters were made available to the universal scholar and polymath. So he obtained some of his plants from the Neuwerkgarten at Gottorf Castle - and then grabbed paper and a quill. In letters, Major asked other gardens for seedlings and seeds. Even in the 17th century, this was a common request, according to Dr Martin Nickol, the current curator of the Botanical Garden. "The area around Kiel was much greener than we can even imagine today," explained Nickol. So Major was able to exchange indigenous plants for exotic tulip bulbs from Turkey.
The collected treasures were researched by the medical professor and his students, who published the plants in a list. 350 years later, the biodiversity of the Botanical Garden still benefits from continuous exchanges. "We receive about 1,200 seed packs every year, and send out approximately 2,500 packs," said Susanne Petersen, Deputy Technical Director of the Botanical Garden. She records the incoming and outgoing orders, and coordinates the seed exchanges.
The result is not only beautiful to look at for visitors. It is the result of scientific cooperation between gardens from many nations and climate zones. Because not everything blooms, flourishes and bears fruit everywhere. The exchanges enable an immediate response to changing needs in research and teaching. Special collections, for example of certain farm crops, are gathered by seed exchange, and cultivated and studied at one location for the duration of the project. The more comprehensive the collection, the better scientists can find answers to research questions, or be inspired by new ideas. The plants are then redistributed back to the network again.
"This is a transnational fraternity, which must work together here," said Nickol, and with his employees is clearly proud to be a reliable exchange partner for more than 450 botanical gardens around the globe.
However, it is not only the network that must work well; the gardeners on site must also work hard. In Kiel, they harvest in the open air from May, when the first early bloomers are ready, until November or December. The yield depends very much on the weather. "2017 was complicated, because it was too wet," recalls Susanne Henning, who has worked at the Botanical Garden for 25 years. "Sometimes we also have bad luck, and the rabbits eat our crops," said the outdoor horticulturist. In the greenhouses, seeds can be harvested all year round. Henning and her colleagues regularly check how mature their fosterlings are, until they patiently collect them by species in many containers. Henning then dries the seeds, and frees them from leaves, hair and other plant debris. Her careful work will be rewarded: well-cleaned and properly stored seeds remain able to germinate for longer. "Even after 60 years, our foxglove seeds will still thrive in moist soil," promises Nickol.
To ensure that there are no mix-ups, each seed is given a name and a number, which is stored in a database. Just like an ID card. With this, they are placed in the seed storage - or as Martin Nickol calls it: "in our vault". Sorted by families, genera and species, seeds in all shapes and colours lie next to each other, waiting for their trip around the world. Every year, 500 to 700 species may be selected through the Index Seminum Horti Botanici Kiliensis. Rare succulents and agave species are particularly popular. But whether agave or stinging nettle: all orders for the botanical gardens involved in the international seed exchange are free of charge, emphasised the team. Since 1669, the sole motivation has remained mutual benefit.
Because in order to preserve genetic diversity and avoid inbred lines among the plants, botanical gardens require "fresh blood" of documented origin, preferably from wild locations. Even more significant are those plants cultivated in Kiel, which could last be collected in the wild in the 19th century. Among other things, their natural habitat was destroyed by industrialisation and climate change. It therefore becomes apparent how important the daily care by expert gardeners is, from the founder Major right through to today's apprentices. Nickol: "Only together can the rich diversity of species be preserved."
Author: Raissa Maas