National Sunflower Association - link home
About NSA Join NSA Contact Us Facebook YouTube
All About Sunflower


Health & Nutrition

Sunflower Seed and Kernel

Sunflower Oil


Banded Sunflower Moth

Sunflower Moth

Video Clips





Biennial Wormwood

Canada Thistle




Palmer Amaranth

Puncture Vine

Redroot Pigweed

Wild Buckwheat

Wild Sunflower

Weed Supplement

Approved Chemicals


Growth Stages


Production Resource Books


Yield Trials/Crop Survey

Crop Insurance

Equipment Buy/Sell

Calendar of Events

Media Center

Photo Gallery

Sunflower Statistics

International Marketing


Meal/Wholeseed Feeding

Sunflower Magazine



Daily Market News
Sign Up for Newsletter
Online Catalog
Online Directory
Google Search
Printer Friendly Version
You Are Here Growers > Weeds > Canada Thistle

Canada Thistle (Cirsium arvense)

Canada thistle
This weed rated the worst weed in Manitoba and the second worst weed in North Dakota in 2008. Canada thistle is a perennial and can spread by seed or rhizome. The seed spreads easily and germinates quickly.

Control Strategies

Canada Thistle
1. Fall burn down is necessary prior to a hard frost, when regrowth is 8-12 inches tall and soil moisture is good. Glyphosate combined with other herbicides can provide good results

2. Express˛ is the only sunflower labeled herbicide that has good to excellent activity on Canada thistle

3. Between row cultivation or hooded sprayer herbicide application

4. Sunflower fields with Canada thistle should be burned down with Glyphosate when sunflower seeds are 35% moisture or below.

Additional Links

Colorado Weed Management Guide (link)

Glyphosate, Weeds, and Crops (link)

KSU Weed Publications (link)

NDSU Crop Production and Marketing (link)

SDSU Weed Control in Oilseed Crops (link)

Sunflower labeled Herbicides (link)

Contact the chemical companies to obtain a copy of the label.


Express herbicide is specific to ExpressSun® hybrids only. ExpressSun hybrids have been developed with a resistant gene to Express herbicide. Applying Express herbicide on non-ExpressSun hybrids will result in extensive damage.

Glyphosate and Aim are labeled for between row hooded sprayer applications.

Top of the Page

copyright ©2016 National Sunflower Association