How do I control thistle?

There are five noxious thistle species in Colorado and four occur in Archuleta County. Chemical control in the spring and fall works great on both species and there are biological control agents available for Canada thistle and musk thistle. Hand-pulling or cutting down the plants works well for biennial species such as Scotch, musk, and bull thistle-which all have simple root systems. Canada thistle has a creeping root system and any disturbance below the surface will encourage new growth from the root system. Repeated mowing can deplete the root reserves of this plant after several growing seasons. Solarization can also kill Canada thistle. Solarization should be done with clear or black plastic that will cover the plant for the entire growing season. Clear plastic works faster than black plastic.

Show All Answers

1. What are noxious weeds?
2. How do I control noxious weeds?
3. How do I control thistle?
4. What services are available to residents of Archuleta County?
5. Are any of the services free?