3. Invasive flags
While the Yellow Flag Irises are definitely beautiful, their dangers aren’t limited to the toxic properties that they host. The Invasive Plant Council of British Columbia, an authority on preserving the local ecosystem, have referred to the Yellow Flag Iris as a “wickedly aggressive plant.”
They stated that no one should plant a Yellow Flag Iris. That said, the species isn’t considered invasive in every part of North America. A single colony of Yellow Flag Irises could host up to hundreds of plants.
The sheer volume and size of each colony present a significant threat to local ecosystems as these Irises can reduce the number of native plants that the wildlife relies on for food.
Furthermore, they might even mess with irrigation and drainage of local farms. This species of Irises spreads far too easily. A single broken rhizome can root itself and then build an entire colony on its own.