Susan points to a yellow flag iris in her garden. She has just cut the foliage and is preparing to dig it out. Photo by K. Cummins

Susan points to a yellow flag iris in her garden. She has just cut the foliage and is preparing to dig it out. Photo by K. Cummins

Comox Valley Nature volunteers educating homeowners on invasive plant in the area

Comox Valley Naturalist (CVN) members recently connected with a number of residents in the Spindrift area that unknowingly had yellow flag iris growing on their properties.

Yellow flag iris (Iris pseudacorus) is on the BC Noxious Weed list and the Comox Valley Regional District (CVRD) Toxic Invasive Plant list. Adapted to wetland environments, it can easily colonize the shores of lakes, rivers and estuaries. Aggressive yellow flag root systems and crowns can clog ditches and marshes to the point of impeding water flow as well as replacing native plant communities. The plant can move further afield by seeds and fragmented root pieces that float in water. Yellow flag’s spread has been abetted by humans intentionally sharing the plants between gardens or unintentionally with the dumping of yard waste in natural areas.

All 10 residents contacted were unaware of the impacts of yellow flag iris and were very receptive to learning strategies to control it: remove seed heads before they ripen (a minimum), dig out patches and dispose of them in the landfill or lay rubber matting to smother plants.

“I don’t know how it came to my garden,” said Susan. “First one plant and then another showed up. I’m happy to get rid of it!”

Laurie accepted a plant from a friend “because it had a pretty yellow flower.”

She has since removed all yellow flag iris from her garden because “it was going take over my yard.”

Roger has struggled to dig out a large patch from the watery ditch in front of his house so is keen to try smothering it with rubber matting.

Supported by a contract with the CVRD, Comox Valley Naturalists hire Sellentin Habitat Restoration to remove the yellow flag iris from the public portion of the beach near Spindrift and Kilmarnock Drive.

“We are all relieved to know that the popularity of the yellow flag iris growing above that beach is waning,” said Karen Cummins, of the CVN wetland group. “Susan had dug out her first patch of yellow flag iris by the time we had finished visiting the residents on our list.”

For more information about yellow flag iris, visit https://bit.ly/3BdObvP

Comox Valleygardening