Kalle Hamm’s new work for Borås Art Biennial 2026, Colour Theory by Plants (2026), has been created in close dialogue with the city gardeners as part of the biennial’s first ever collaboration with the Borås Flower Programme, the city's annual flower display. Hamm’s starting point was traditional plant dyeing practices from pre-industrial times. The plants were selected and organised into four colour themes, based on the shades produced in the dyeing process. The planting patterns were inspired by the manhole covers in Borås.

Hamm’s work draws connections through time, not only in relation to textile production practices, but also between the natural processes of water circulation, the early industrial use of the Viskan river as a source of water intake and discharge, and the complex network of pipes in the modern sewage system. The Flower Programme is installed throughout the city, including in the City Park, where early textile dyeing factories were located; in Annelunds Park, which was created by a wealthy factory owner; and by the Druvefors hydropower dam and the railway station, both originally built to serve the industry.

At the Borås Art Museum, Hamm is showing a video work, Working in Public Space (2012–2016), made in collaboration with Dzamil Kamanger. The sound works Dahlia, Chrysanthemum, Sunflower (2014) by Hamm and Lauri Ainala are based on field recordings of three flowers also included in Colour Theory by Plants, and can be found at the Textile Museum and the Art Museum.

The work of Kalle Hamm (born 1969 in Rauma; lives in Helsinki, Finland) is focused on the shared history and migrations of people and plants. With artist Dzamil Kamanger he has realised many conceptual gardens such as the Immigrant Garden and the Garden of the Undocumented. Together with the Band of Weeds sound collective, Hamm has also performed and produced records, exploring the world through the perspective of plants.