Picture above: Nettles in the project cultivation plot. Photo: Ulrika Dahlberg

Nettle (Urtica dioica) is a sturdy, perennial plant that also thrives in a cooler climate, as in Finland. For gardeners it can be quite a nightmare as a weed and many struggle to get rid of it in their fields. In May 2024 we set out to do the opposite – to establish a nettle field. The plan was to experiment with sowing and to use the harvest for developing food and fibre products with local collaborators. What could possibly go wrong?  

Germination of Seeds

We started the project with spring sowing half of the 0,2 ha plot we rent from Västankvarn research farm in Inkoo. The plot had been fertilized with manure to ensure sufficient amounts of nutrients. We knew spring might not be the best time for sowing, since the nettle seeds could benefit from a cold period to start growing. Nothing germinated during the summer, so the whole plot was sown again in autumn. This time we were more hopeful. However, spring and summer came, and we could not find a single nettle growing in the field. The richness of other vegetation indicated the field was very nutrient rich. A test in the laboratory confirmed poor germination rates for the seeds we used. Part of them were bought from a Finnish farm and part of them were collected by us and a kind colleague of ours. At this point we started to feel slightly hopeless but giving up was not an option. We needed to execute plan B: to transfer nettle plants to the field.

Project leader Ulrika looking depressed by the challenging nettle cultivation. Photo: Samica Sadik.

Planting Nettle and the Current State of the Field Experiment

On June 30th, 2025, we launched an exciting new phase of the project. To set up the trial, we carefully prepared the soil and established four plots based on previous Finnish nettle studies, each measuring 1 meter × 1 meter. In each plot, we planted ten wild nettle plants collected from the surrounding area, arranged in two neat rows of five, totaling forty plants. These plants varied in the number of stems they had when transplanted, giving us a natural diversity to observe, and from the very start, we created a solid baseline for weekly monitoring while closely observing how plant density affects nettle growth and spreading.

The plants in the plots are already thriving and showing a lively range of growth and adaptation, creating a small but vibrant patch of greenery. Even those that faced challenges, from caterpillars nibbling at the leaves to minor damage on the stems, are bouncing back with fresh vigor and healthy growth, creating a living display of nettles’ remarkable resilience and enduring strength. The field is already revealing fascinating patterns of growth and is continuing to provide knowledge for cultivating nettle.

Project interns Veena Ariyasena and Chanika Jayawardana planting nettle. Photo: Samica Sadik

What We Learned

Through this phase, we gained valuable insights into nettle’s growth and adaptability as well as the realities of running a field experiment. We keep observing how soil, spacing, and local conditions affect growth and learn firsthand the challenges of managing small experimental plots. Especially when it comes to experimenting with an unusual crop there are many uncertainties – for example why seeds sometimes germinate and sometimes not. One general conclusion at this point is that establishing a nettle field requires time and patience, but once the nettle is established it is there for years to come.

Field experiments are always a journey of discovery, and sometimes things do not go as expected. Some plants may grow differently than planned, and unexpected challenges can arise and then be solved naturally. Yet these moments are the most valuable because they allow us to test new approaches and gain practical insights that can be applied to improve nettle cultivation. Each challenge helps us adapt, refine our methods, and understand the crop and the process better. Surprises can be turned into opportunities for learning and into tangible results to be published later.

The project NyNässlä – Nettle for fibre and food in Uusimaa is carried out in collaboration with Nylands Svenska Lantbrukssällskap at Västankvarn research farm. Funding has been granted from the European Union, via the Uusimaa Centre for Economic Development, Transport and the Environment (ELY Centre), Svenska kulturfonden and Stiftelsen Finlandssvenska Jordfonden.

Ulrika Dahlberg is the project leader of NyNässla and Veena Ariyasena is a student in the Sustainable Coastal Management programme at Novia UAS, doing her internship in the project.

The blogpost has been reviewed by Novia's editorial board and accepted for publication on 16.9.2025.