Weed of the Month: Shepherd’s purse

Shepherd’s purse seeds germinate in late summer and early fall (a small percentage may germinate in very early spring too). This onset of growth before winter really sets in is how this group of weeds gets the name “winter annuals”.  The seedling’s first leaves form a low growing rosette – a circle of leaves.

The first leaves are also rounded at the tip and the margins have no or very few lobes. As the seedlings grow, the leaves become more toothed in appearance.  They are dark green and the young leaves have hairs on the top surface. 

The most visible part of shepherd’s purse is the flower stalk. The flowers are very, small and white; appearing in spring to early summer. The stalk itself reaches a height of 4 – 24 inches. The seed pods are very distinct taking on a heart or triangular shape. The pods are also flat.

Just like a number of other weeds, hand removal is a viable management option, though it may be labor intensive for a heavy infestation. However, the rosettes may be hard to notice since they grow low to the ground.  The flower stalks make them very visible, but the plants need to be removed before they set seed. 

There are many pre-emergent herbicide options for shepherd’s purse.  These include:

• prodiamine (Barricade)
• flumioxazin (Broadstar/SureGuard)
• dithiopyr (Dimension)
• oxadiazon + pendimethalin (Jewel)
• pendimethalin (Pendulumn)
• oxyfluorfen + oryzalin (Rout)
• oryzalin (Surflan)
• benefin + oryzalin (XL)

Post emergent herbicide options are:

• bentazon (Basagran)
• glufosinate-ammonium (Finale)
• diquat dibromide (Reward)
• glyphosate products
• flumioxazin (SureGuard)