Why Are The Scots The Toughest Guys In The World?… Because They Wear Kilts In A Country Where Thistles Grow Waist High!
I don’t know why this highly invasive, perennial weed is given the status of ‘Canadian’ when its true origins are from the Mediterranean area of Europe and was introduced to North America in agricultural seed shipments in the 1600’s.
It is now widespread throughout North America and it is difficult to control and it reduces pasture capacity, wildlife habitat, hinders reforestation and landscaping efforts. It displaces native vegetation and is prickly and nasty to step on if it decides to make your lawn it’s new home. It grows in patches and does best in low fertilized open areas and loves disturbed soil areas in high moisture areas and with our cooler wet spring have had a good environment to grow.
Canadian Thistle has an extensive root system that can have a spread of 20 feet and can be down as far as 10 feet. It reproduces by seed that will start to develop about mid July and each plant can produce 1500 seeds that can lay dormant and viable for 3 to 6 years. These seeds will appear 8 to 10 days after flowering and somewhat resemble dandelion flowers when they turn to seed and will spread with the wind. To help control this pest you should best prevent them from producing seed by repeatedly clip the plant off at ground level.
As well as growing from seed they will also grow readily from the root system and any little piece of that root system will grow into another Canadian Thistle which can be problematic if you choose to dig the plant out. Also if you try to pull out the plant when first germinating in an area like your lawn it may split at the root and then will cause two to grow. It will take a concentrated effort to rid an area of Canadian Thistle.
Fertilization and planting plants that will choke it out and cutting it down to soil level continuously are the best methods to keep it in control in your yard however that can be difficult in a crop field.
Tilling the plant under and planting a cover crop of Alfalfa or Sweet Clover is a method that will help choke it out over several years.
Be sure to use good sanitation practises by cleaning your machinery well as the smallest piece of the root can easily be spread to unaffected areas. Systemic Herbicides can be used and organic options include Bonide Weed Beater, Natural Armour Weed and Grass Killer are both Glyphosate free.
It is illegal to transport, propagate or sell Canadian Thistle.
Well it is summer and the heat is upon us. I’m not looking forward to the heat we will be experiencing over the next little while although we will not be experiencing the extreme heat that we had last year or that parts of Europe and the States are suffering. Stay cool and hydrated!
Happy Gardening
Samantha Nason
BS Ranch & Greenhouses
250 547 6567 • samanthanason@hotmail.com
