The Plant Hunters’ Adventures

Welcome to an exciting world of adventurous journeys to distant lands undertaken by plant hunters and enthusiasts in search of exotic plants that we have enjoyed for centuries. This year, we want to highlight these adventures and provide a glimpse into the world of plant hunters, acknowledging the dedication required for us to comfortably plant species from all around the globe today. It hasn’t always been easy; many expeditions were costly, risky, and uncomfortable in various ways. Yet, the plant hunters’ curiosity and passion for plants outweighed any potential obstacles.

Following in the Footsteps of Plant Hunters

The act of collecting plants has evolved from seeking food sources for survival to discovering enticing, previously unknown species. During the Age of Exploration, many voyages aimed to discover new continents and their riches, including exotic plants. The pursuit of plants with high ornamental value intensified during this time, as it became lucrative to introduce these rarities. With the rise of orangeries in the mid-1600s, exotic plant introductions increased significantly. Sweden’s first botanical garden was established in Uppsala in 1655, complete with an orangery, opening up new possibilities for overwintering plants in Europe.

During the 17th and 18th centuries, numerous voyages were undertaken to discover new continents and their riches – which included exotic plants. There was an equally fervent search for plants with high ornamental value because fortunes could be made by introducing these rarities. In conjunction with Sweden’s era as a great power, the introduction of new plant species increased significantly. In the mid-17th century, orangeries became a more common feature. Sweden’s first botanical garden was established in Uppsala in 1655, complete with an orangery. This opened up an entirely new world in terms of which plants could survive the winters in Europe.

In Sweden, Carl Linnaeus sent out his disciples, known as naturalists, in the 1700s to collect and document plants and animals that were previously unseen in the Western world. These plant expeditions often faced severe challenges, with fatalities not uncommon due to diseases, hostile indigenous populations, and storms. Of the 17 naturalists that Linnaeus sent out on expeditions, 7 perished during their travels; diseases, hostile indigenous populations, and storms were common features of these hardships.

During the 19th and 20th centuries, professional plant hunters emerged, many sent by large nurseries and arboretums, primarily to explore China. Western China attracted attention for its rich flora and intriguing botanical history. The emergence of more nurseries and improved transportation facilitated the spread of new plants. Over a hundred years, parks transformed from containing only a few species like linden and elm to featuring a vast array of plants.

An Era Ends…or Does It?

In the late 1960s, many in the industry claimed that all hardy plants that had ornamental value in the Western world had been discovered, and that all the interesting regions had already been explored. However, it soon became apparent that most new introductions were products of hybridization rather than wild species. Those species that were less than hardy were crossed with hardier ones so that they could survive and thrive. Yet, new discoveries continue to occur. Arguments for continued plant collecting include reintroducing lost plants and searching for interesting variations of known species. Plants are living organisms that sometimes need rejuvenation or replacement, and new discoveries can occur spontaneously in both nature and horticulture.

In the green sphere, discussions about provenance and its correlation to hardiness arose. Provenance is significantly more complex than the simplified Swedish hardiness zone map. Within the same plant zone, there can be various microclimates that significantly differ, affecting plant conditions. Likewise, a plant’s provenance is crucial, as a plant’s ability to thrive depends on its place of origin, in addition to meeting its basic site requirements.

In the late 1970s, many new plantings in Sweden suffered poor growth or died due to the import of cheap material from Eastern Europe. Mislabeling was common, and the plants had unknown provenance. This issue prompted projects by the Swedish University of Agricultural Sciences at both Ultuna and Alnarp. Successful projects included p80 – New Trees and Shrubs, which involved large-scale trial plantings of foreign plant material. Much of this material ended up at the Elitplantstationen, an organisation specialising in plant breeding, providing the Swedish horticultural industry with genetically sound plant material for sustainable plantings.

The Quest for Trees and Shrubs in a Changing Climate

Plant collecting has gone from looking for plants for sustenance to seeking undiscovered, alluring species. Later, efforts focused on finding hardy plants of known genetic origin to create sustainable and lush plantings. And there are still reasons to keep looking for plants, as well as challenges that come with doing so.

Research and ongoing efforts focus on discovering new climate types for both highly ornamental plants and new crops to meet future climate change challenges. This work addresses partially unknown goals and boundaries and will affect all living organisms. A plant’s provenance is crucial in this work, and various climate change simulation models can match a plant’s origin with a projected future scenario.

Trees will undoubtedly play a vital role in the future, especially in urban environments, where the importance of trees and shrubs is paramount. Trees and green spaces provide ecosystem services such as air purification, water and temperature regulation, carbon sequestration, and recreational opportunities.

Boverket, The Swedish National Board of Housing, Building, and Planning has a mission to coordinate the national climate adaptation work for the built environment. One of their recommendations is that the majority of municipalities should more extensively embrace and integrate urban greenery and ecosystem services in urban environments in planning, construction, and management in cities and urban areas by 2025.

The Swedish Environmental Protection Agency has set a goal of at least 25 percent tree canopy coverage in the built environment by 2030. To achieve such a goal, it is of great importance to cherish and protect old trees that are already established. This is not only for the sake of climate but also for increased biodiversity and human well-being. Therefore, it may be even more important to continue planting the right trees in the right places with plant material that can withstand future climate changes. The city trees we planted 40 years ago may not thrive in a future warmer climate. The quest for new plants and new climate types of existing trees is still highly relevant in 2024, even though plant hunters have become more modern and adventures fortunately less risky.

Tor G. was born in Stockholm in 1914 (1999) and was interested in botany and horticulture from an early age. After completing his basic education and doing several years of work around the Stockholm area in the 1930s, he considered himself ready for a more advanced theoretical education. He intended to become a landscape architect and had a desire to work with plants and applied botany but was rejected in his application to the Swedish University of Agricultural Sciences. Nitzelius then turned his gaze to Germany and began as a novice at the higher gardening school known as Versuchs und Forschungsanstalt fur Gartenbau in Berlin-Dahlem. And it was precisely this turning point in his studies that Nitzelius expressed as decisive for what was to come. The rejection of his application would have been seen as unfortunate in terms of his career, as it was considered more prestigious to be a landscape architect, but it led to a much greater experience for him, both professionally and as a human being.

Nitzelius became particularly fascinated by Asian plants, largely thanks to the Asian section of the Berlin-Dahlem botanical garden, which made a deep impression on him. His education was right next to this botanical garden, and thus he had great opportunities to study this plant material on his own. He did so as often as he got the chance.

Around the 1940s, the so-called ice winters arrived and caused great devastation for the more exotic plant species, both in Sweden and in Berlin. The severe winters became the starting point for Nitzelius’s quest to obtain hardier and more cultivable plant material better suited to our latitudes. This passionate plant man did not settle for reconciling himself to the fact that some exotic plants have no cultivation value for our latitudes: his thoughts were about finding exotic plant material that was more adapted to our climate. That is, plants with the right provenance.

Another reason why Nitzelius wanted to go out into the world and become a plant collector came from being influenced by his teachers and mentors at university, who became his role models. Nitzelius directed his first trip to the Czech Republic and the Carpathians; he himself thought this was a bit tame considering his great ambitions.

In 1941, Nitzelius returned to Sweden, and between 1943 and 1952, he was employed by the Stockholm City Parks Department as a tree expert. He then became associated with the Gothenburg Botanical Garden, between 1952 and 1976. There he served as an assistant, superintendent, and prefect for the park. Nitzelius, who was already recognized as competent, was immediately sent on a collection expedition to Japan in 1952. This was one of several trips there.

His last trip to Japan as an employee of the Gothenburg Botanical Garden was in 1976, in a Nordic collaboration called the Nordic Arboretum Committee. The association was based on conducting plant expeditions to find cultivable plants for Nordic conditions. Several interesting plant introductions were found during the trip to Japan, and in addition, Tor made his own detour to the South Korean island of Ullung-do, where Tor found, among other things, the Ullung rowan, Sorbus ulleungensis.

It was after this last trip that Tor began to plan Norrviken, which became Tor’s Park. But he was also involved in many other things at Norrviken and was active here between 1973 and 1995. But the story of Tor and his adventures does not end here in Halmhuset, but they continue out into the park. We at Norrviken want to celebrate this plant hunter and tell about his deeds and footprints in our park and to give us ordinary plant lovers an insight into his adventures and passion. Follow in the footsteps of the plant hunter at Norrviken; at selected places in the garden, we’ll tell you more about Tor’s work!

In Villa Abelin, there is also a beautiful library that, beginning this year, houses Tor Nitzelius’s private library, which has been donated to us to manage by his son, Tor Karl-Fredrik Nitzelius.