Caetano Mendes Dias

The smell of Japanese Knotweed

Diving into knotweed scents

Japanese knotweeds seem to be odorless but when we break them, suddenly a sweet odor spreads through the air. Discover different methods to capture this scent.


Methods overview - Graphic composition of an existing image. Original image author: W.carter

If we come closer to the Japanese knotweed and scrub their leaves, we will notice a slight fresh smell similar to rhubarb and cut grass. What we smell is the volatile organic compounds (VOCs), which are a self-defense mechanism that plants have to protect themselves from any external dangers, such as insects, mammals, fungi, and even the sunlight. If we would compare it with chemical warfare, the VOCs would be the fumes of war.

However, their odor is also their identity. It is what distinguishes them from other plants, and makes them unique. The more we breathe them in and smell them, the more we get to know them. We create a reciprocal relationship with the plant, where they smell us and let them be smelled by us. By exploring the olfactory world of this story we can imagine new ways of relating to invasive species and open up new ways of dealing with them.

At the Aroma Lab, we are currently busy exploring different ways of extracting the Japanese Knotweed scent using different methods such as:


Knotweed fermented tea -

Dry knotweed chunks fermententing.



Scent composition -

Composing a fragrance based on the knotweed, using the aroma library.



Distillations -

Distilling dry knotweed chunks.



Tincture -

Tinctures mixing knotweed powder and ethanol.



Pouring the powder -

Pouring knotweed powder.



Tincture color -

Tinture color.