Hound’s Tongue – Early Detection and Rapid Response

Published by Rob Underhill on 03/27/2026 03/27/2026

Thanks to observations by community members, we learned that a plant species called hound’s tongue (Cynoglossum officinale) is growing at the top of Mt. Parke around the helipad. Hound’s tongue is designated a noxious weed in British Columbia because of its economic and environmental impacts. This species is a biennial, growing as a low rosette of leaves in year one, with flower stalks bolting up 30-120cm in year two, producing up to 2,000 seeds. It can crowd out native plants, is toxic to livestock, and its large, burred seeds stick in the fur of pets. This is the first time this species has been detected on SḴŦAḴ | Mayne Island, and there is only one known location here – making this an opportunity to manage it before it can spread.

There is no public access to the property with the helipad and communications tower where the hound’s tongue is growing, though it is nearby to Plumper Pass Community Park and the recently expanded Mt. Parke Regional Park. The property with the helipad is owned by the Federal Government and is managed by the Canadian Coast Guard (CCG). The CCG also leases portions of the site to a third party: SBA Communications Corporation. In the fall of 2025, the Mayne Island Conservancy secured permission from the CCG to access the property for the purposes of monitoring and managing the hound’s tongue population.

We began management efforts in December of 2025, in collaboration with the CCG, who met us on-site and were able to unlock one of three fenced areas so we could dig out the plants found there. There are two additional fenced areas that CCG staff did not have access to. We have been in contact with SBA Communications and are working to gain access to the remaining fenced areas. With the help of volunteers, we continued digging up plants outside of the fenced areas in January of 2026, but at least 10 more hours of work are needed to remove the existing plants for this season.

Unlike species like Scotch broom, hound’s tongue seeds are reported to have a “short seedbank,” meaning the seeds don’t survive for very long in the soil. This is good news, and means that if we can successfully dig out all the plants every year, we should be able to eradicate this noxious weed from SḴŦAḴ | Mayne Island within the next 3-4 years. This type of management is called “early detection and rapid response” (EDRR) and is widely accepted as the most efficient form of management for invasive species.

Other invasive plants the Mayne Island Conservancy has targeted for management under an early detection rapid response management include gorse, giant hogweed, Japanese knotweed, Himalayan knotweed, Maltese star thistle, milk thistle, egg-leaf spurge, and Italian arum. These species occur in few enough locations that they could be eradicated from the island with a reasonable amount of effort if timely action is taken.

We have successfully eradicated all known gorse, Himalayan knotweed, and giant hogweed from the island. Japanese knotweed is now limited to two known locations. Maltese star thistle is located adjacent to SḴŦAḴ | Mayne Island and we are monitoring nearby shorelines annually to detect any spread. Egg-leaf spurge and Italian arum have been found on private lands, and we are encouraging landholders to remove them. If you think you may have these species on your property, please let us know and we can help provide information on management methods. The Province of BC may be able to provide help removing species on their provincial eradication list such as egg-leaf spurge.

With limited resources to invest in invasive plant management, it is critical that we direct our resources where they can have the biggest impact. This means focusing on species where eradication is possible, and prioritizing management of more widespread species in high-value conservation areas. Private land stewards make a significant difference in managing invasive plants on their properties.

Thank you to the volunteers who have supported this work. If you would like to join us for our next trip to the top of Mt. Parke to remove hound’s tongue, let us know and we will add you to our email list for habitat restoration events.