Yellow Flag Iris Management

Yellow Flag Iris (Iris pseudacorus) is an invasive plant that impacts local wetlands and waterways. Its dense growth outcompetes native species, greatly reducing biodiversity, and it can be toxic to animals and humans, causing skin irritations. A contractor will be on site in late-summer to help prevent the spread of Yellow Flag Iris in the French Creek Estuary Nature Preserve.

Vegetation management will include removing seed heads, carefully hand-digging rhizomes (horizontal roots) and covering remaining vegetation with a benthic mat. Benthic matting is a restoration method that involves cutting the plant down to its roots and covering the area with heavy fabric to temporarily prevent light from reaching the invasive plant roots, thereby reducing re-growth. The area will be monitored for a full year to make sure the yellow flag iris doesn’t grow back.

You can learn more about best management practices for Yellow Flag Iris from the Invasive Species Council of BC.