The Whitehall Project: Looking for Canada Thistle Fungus Release Sites in Jefferson County

The Whitehall Biological Weed Control Project is up and running this season, modified a bit of course for COVID safety. Our first order of business is looking for 8-10 Canada thistle fungus release sites. This will entail two visits to each site. One now (May/early June) to set up a long-term sampling transect. The second visit will be in September/October to infect the plants with the fungus. Many Montana sites are showing fairly severe damage to the Canada thistle patches the season after the initial release.

The Canada thistle rust fungus (Puccinia punctiformis) is being used in several wes...