Tisa is a company contracted by the City of Ljubljana which takes care of public green areas in the capital and across of Slovenia. They also provide a service for individual needs, for example anyone who wants a tree cut on their land can call them. As the municipality is trying to solve the problem of quickly spreading invasive plants, Tisa is the one of the companies in charge of dealing with the Tree of heaven and Japanese knotweed. We decided to collaborate with them because they best know the areas where invasive plants are present. When we visited their space for the first time we were amazed by the quantity of wood stored there! The majority of wood they collect is used for composite wood material (MDF), but the biggest logs of more valuable types of wood are sold. As an invasive species, the Tree of heaven is not sold, but instead minced for composite wood material. This is where we wanted to step in and explore if the wood is appropriate also for other uses. Tisa provided us three logs, two of them being exceptional, 4m long, 30-45 cm wide and no curves or branches, while the other was slightly curved and with some branches but 60 cm wide. It was amazing to see how fast those trees grew as some rings were distant one from another more than 20mm. The next step was to transport the logs to the mill and saw them into 25mm boards.