Invasive Plants, Pacific Northwest
Many ponds, lakes, and Island gardens of Vancouver Island are surrounded by a beautiful water loving plant called Yellow Flag Iris. They are harmless looking and quite fetching at first glance, but don’t let its pretty looks fool you, for this plant can cause serious problems to the local ecosystems.
This iris grows in dense patches that will force native plants out, alter the natural habitat and block water flow. The plant grows over all of Vancouver Island.
Sword shaped leaves and bright yellow flowers distinguish the plant, making it a gardening favorite world wide. Native to Europe, the British Isles, North Africa and the Mediterranean region, yellow flag iris is considered an invasive plant in BC.
Yellow flag iris reproduces quickly through seed dispersal and horizontal root systems, creating thickets in the water like cattails and reaching up to 1.5 m in height. Several hundred flowering plants may be connected through rhizomes under the water and fragments can form new colonies when they drift downstream.
This invasive plant is sought after by gardeners. Yellow flag Iris is sold in most nurseries. The plant is very popular making it hard to control its spread. 3 out of 4 invasive plants invasive plants came to the island as ornamental’s.
Help your community protect local resources by managing invasive plants. There are hundreds of native aquatic plants that are critically important to parts of a lake or river ecosystem and invasive plants force them out. Do not buy or dispose of any invasive plant, please.