The wild Yellow Flag Iris are starting to bloom now, a few weeks after our garden Iris. The Yellow Flag is a class C noxious weed in Washington state and is listed on the noxious weed list in many other states. The primary concerns for the noxious listing are:

• Potential livestock toxicity
• Human skin irritation
• Out-competing other plants in ecosystem
• Clogging drainage pathways

The plant was originally brought to the continent in the early 1900s as an ornamental though it rapidly escaped containment and began naturalizing. This map shows the distribution throughout the US.

I think "escaped" is a bit understating the magnitude of the invasion judging by the map...

The Yellow Flag is not all bad though as the plant has been proven to take up heavy metals from water and soils which can be very useful for soil and water remediation work. When applied correctly and in an area that is of little concern to other species, the Yellow Flag can be an effective tool. The issue is the veracity of the plant's rhizomes and the difficulty in removal if the placement is not correct.

Our stand of Yellow Flag sits along the edge of the creek and has crept slightly into the main creek bed. The majority of the rhizomes have remained above the main water level. The stand sits directly next to one of the small tunnels that allows the creek to pass beneath our road to our farm. The only concern I have for the plants and their location is the very slight potential for the rhizomes to start infiltrating the tunnels, but so far they have shown little desire to move that direction.

Even though it IS listed as noxious in many states, the plants will be going to seed soon so if anyone would like seeds of the Yellow Flag Iris I would be happy to send you some in a few weeks once they have fully grown.

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