Field crew chasing alien invader

You may have noticed hoary alyssum with its fluffy white flowers and flattened seed pods along the roadsides or in a local pasture. What you may not have realized is that this seemingly harmless plant is actually an invasive non-native plant species that is beginning to spread.

Hoary alyssum is toxic to horses, causing swelling of the lower legs, fever, and diarrhea. In rare cases, ingestion of large amounts of hoary alyssum can lead to death. When this plant spreads into hay fields, it can be unknowingly cut and bundled leading to contaminated hay and potential illness. In fact, farmers can no longer sell their hay in some areas where hoary alyssum is infesting.

The Central Kootenay Invasive Plant Committee (CKIPC) had noticed that hoary alyssum has appears to be spreading. This year, they are conducting an inventory of this species (along with three other invasive plants) to determine how abundant this plant is and how far it has spread.

“We are surprised by how much hoary alyssum is around,” says Dawn Wrangler, Invasive Plant Technician conducting the inventory. “This plant has really taken off, especially in the Fruitvale and Trail areas. It is a concern for everyone, but especially for people with horses or that grow hay.”

Because hoary alyssum was introduced to Canada without natural predators to keep it under control, it will continue to spread and out-compete native plants. Some people describe the infestation of invasive plants as “biological pollution” since they impact the environment and continue to spread.

“The best thing that residents can do is learn to identify invasive plants like hoary alyssum, and to control them on their property,” says Val Miller, Agrologist who is overseeing the project. “If everyone was responsible for removing their plants then we can prevent this plant from spreading, and from impacting local farmers and horse-owners.”

Hoary alyssum can be hand-pulled effectively. Pulled plants should be carefully disposed of to ensure they do not spread.

Added on July 13th, 2005 - Return to Special Features