Pest Profile: Shepherd’s Purse

TYPE

• Annual
• Broadleaf

IDENTIFICATION

Shepherd’s purse resembles its cousins in the Mustard family but can be distinguished by its orange-yellow to reddish heart-shaped seed pods that attach to the stalk at the pointed end. Its stems are branched and can grow 10-60 cm high, with leaves that alternate about 1 per lobe. Leaf blades are variable and oblong in shape, shallowly to deeply and coarsely toothed, and about 5-10 cm long. Flowers bloom from early spring to late fall. They resemble wild mustard, but can be distinguished by their white colour and smaller size (about 3-8 mm across), and gather in rounded clusters at the ends of stems and branches.

CONTROL TIPS

• Winter annuals like shepherd’s purse can be hard to control in the spring if they germinate in the fall or late summer. Treat with cultivation or a herbicide application in the fall prior to snowfall for best results.
• Shallow, vertical tillage can help control shepherd’s purse.
• Group 2-resistant weeds have been found in Alberta and Saskatchewan.
• If attempting to control in the spring, treat early with full rates of a registered broadleaf herbicide. Bromoxynil with MCPA and clopyralid with MCPA are two effective combinations.
• Glyphosate can be effective in post-harvest and pre-seed applications.

REGISTERED HERBICIDES

• 2,4-D Ester 700
• ADAMA GLUFOSINATE 150 SL
• BADGE^®
• DAVAI^® 80 SL
• DAVAI A PLUS™
• DAVAI® Q PLUS
• ESTEEM ALL IN™
• ESTEEM^®
• EMPHASIS®
• FORCEFIGHTER® M
• FORCEFIGHTER ALL IN™
• MCPA Ester 600
• OUTSHINE ALL IN™
• OUTSHINE®
• THRASHER^®
• RUSH^® 24
• RUSH 24 ALL IN™
• PRIORITY^® + Glyphosate
• SQUADRON^® 
• TOPLINE^®
• PHANTOM^® 240 SL
• PYTHON®
• INVOLVE^® 50 WDG + Glyphosate

Please read each label to determine which herbicide is appropriate for the crop affected.

REFERENCES AND ADDITIONAL READING

“Ontario Weeds: Shepherd’s Purse.” Ontario Ministry of Agriculture, Food and Rural Affairs. Online. https://bit.ly/2JrZiIn

“Shepherd’s-Purse, Capsella bursa-pastoris.” WeedInfo.CA. Online. https://bit.ly/2yFTEy7

“Shepherd’s Purse.” Manitoba Agriculture. Online. https://bit.ly/2yHyzDb

Raine, Michael. “Weed of the Week: Shepherd’s Purse.” Western Producer. 21 May 2015. Online. https://bit.ly/2qqX6rX