A 13-year-old from Co Kerry scooped three awards at this year’s SciFest at Munster Technological University for her project on eliminating Japanese knotweed.

Nature enthusiast Grace Ní Ifearnáin from Ghaelcholáiste Chiarraí carried out a project called Nature takes on nature: eradicating Japanese knotweed.

The aim of Grace’s project was to determine whether or not the black walnut tree can inhibit the growth of Japanese knotweed and, if this was the case, to investigate the correlation between the two further.


Native to North America but growing in Ireland, the black walnut tree produces juglone, an organic compound, which it spreads through its roots.

13-year old Grace Ní Ifearnáin won three awards for her project at SciFest.\Catrina Heffernan

Juglone has poisonous properties, which come to fore when the tree is seven years or older.

Japanese knotweed, while native to Japan, is now widespread and classed as an invasive species in Ireland.

Grace wanted to find other ways to inhibit the growth of Japanese knotweed that are both cheaper and more environmentally friendly than killing the plant by injecting it with glyphosphate.

The Tralee student had noticed a lot of Japanese knotweed growing on roadsides and how it was preventing other plants from growing. This resulted in Grace deciding to undertake further research on the plant.


Grace’s research showed that Japanese knotweed is widespread in Ireland, especially in her native county of Kerry.

By looking through various documents, such as biodiversity maps Ireland, and through her own observation, she concluded that there was no Japanese knotweed plants growing within 150ft of black walnut trees.

She said this shows that there is a possibility that the black walnut tree can inhibit the growth of Japanese knotweed.

As well as sourcing sightings of Japanese knotweed, Grace also sourced black walnut trees that were older than seven years old in Ireland.


Grace has enjoyed tremendous success with her project, scooping up three awards at this year’s SciFest – the environmental award, junior life sciences category award and best project award. There were almost 600 entries.

However, the ambitious student has no plans to halt her research, planning to carry out further replication studies using larger samples of black walnut trees.