Winter Days 2026! 18th International Perennial Plant Conference - ISU

The 18th edition of the International Perennial Plant Conference, "Winter Days," took place from February 13 to 15, 2026, in the picturesque town of Grünberg, Germany. With participants from 15 different countries, the conference gathered 107 passionate nurserymen, botanists, gardeners, and landscape architects for three days filled with learning, networking, and inspiration.

Participants included a diverse array of experts and enthusiasts in plant cultivation, including Gerben Tjeerdsma, moderator and member of the ISU board, as well as speakers like Tom Coward, Vania Slavia, and Henrik Sjöman.

Gerben Tjeerdsma and Bildungsstätte Gartenbau were the organizers, and the purpose of the "Winter Days" conference was to promote knowledge exchange and create a platform for discussions on plant breeding and conservation of plant varieties, which are crucial for the future of gardening and landscape architecture. This year’s winner of the ISU scholarship Klara Kovacs was presented. She is a perennial gardener from Austria.

The conference began on Friday with the ISU board expressing gratitude to Bettina Banse for her years of dedicated service and outstanding contributions, presented with a basket full of goodies. They also welcomed the new manager, Linnéa Dickson, who will carry on Bettina's work. The first speaker of the day was Tom Coward, head gardener at Gravetye Manor in England, who spoke about the estate's creator, William Robinson, a pioneer in garden literature, and Tom and his team's ongoing work and development of the garden today. Vania Slavia, a landscape architect and nurserywoman from Chile, took us on a visual journey through the biotopes of Patagonia, showcasing fantastic (and very tiny) plants from her field studies. The day concluded with Connor Smith, head of the rock garden at the Botanical Garden in Utrecht, who presented garden-worthy perennials from his global travels. The audience became particularly engaged when the discussion turned to the black poppy, Papaver ‘Black Magic’. The evening wrapped up with a somewhat challenging, but fun trivia contest focused on perennials and then mingling at the Bayerstaube, where participants enjoyed a cold beer and exchanged experiences.

Saturday began with Remko Beuving, a passionate gardening amateur, who demonstrated how he created a tropical jungle in his garden in the Netherlands. He shared the step-by-step process of building it, complete with a large pond and numerous tropical plants, and how he inspired at least one neighbour to plant trees and perennials in their garden. Nurserywoman Jana Holzbecherová, who also is ISU's president, spoke about her father's legacy and the impressive rock garden in Brno, Czech Republic, that he created. Jana has followed in her parents' footsteps and now runs the family nursery, focusing mainly on alpine plants and sharing her extensive knowledge. After lunch, participants ventured to the Ibero-Atlantic ecoregion in northern Spain with botanist Luis Carlón Ruiz, who presented resilient perennials from various biotopes. Luis showcased images from incredible places and explained how the region differs from other parts of Spain with less drought and cooler summers. The next speaker, Susanne Peters, a nurserywoman from Germany, shared her passion for Helleborus, including her vast knowledge and the latest news in the genus. The day concluded with Vania Slavia discussing her experiences and challenges in promoting the use of native plants in public plantings in Patagonia.

Sunday, the final day of the conference, began with bulb specialist Eric Breed from the Netherlands, who inspired the audience with stories and images of his work conserving historical varieties as well as developing new varieties of bulb plants like Narcissus, Tulipa, Camassia, and many more. The last speaker, Henrik Sjöman, shared his expertise on tree compositions in a changing climate, presenting examples of the most resilient trees for future conditions. After a communal lunch, it was time to depart, but first, participants gathered around several boxes full of pots with spring bulbs that Eric Breed had brought from the Netherlands! What a perfect ending to a fantastic conference!

The 18th International Perennial Plant Conference - Winter Days proved once again to be a solid platform for knowledge exchange, where participants not only learned about rare perennials, cultivable varieties, and techniques but also forged valuable connections within the industry. With a wide range of topics and an engaged audience, the conference was a memorable and inspiring event. We look forward to next year's conference and hope to see even more enthusiasts in perennial cultivation and use!