Waterhemp plants found in a soybean field in Norfolk county during the 2019 growing season. They were eventually confirmed to be resistant to group 2, group 9 and group 14 herbicides.

Managing Ontario’s devious weed duo

Strategies offered on how to deal with herbicide-resistant fleabane and waterhemp

Are Canada fleabane or waterhemp consistent or growing problems on your farm? If so, it might be time to change the approach to chemical controls, according to field crop and […] Read more


Side-by-side comparison of Palmer amaranth, waterhemp, and Redroot pigweed. Waterhemp and pigweed look similar at this stage.

Common waterhemp: An adaptable and potent foe

Problem weed continues to spread in Ontario while diversifying its herbicide resistance capability

Waterhemp with resistance to multiple herbicide groups continues to spread across the province, in part because of its similarity to other pigweed species.  First detected in Lambton County in 2002, […] Read more


VIDEO: Water hemp weed management

VIDEO: Water hemp weed management

Field Talk with Chris Snip

In this edition of Field Talk, Farmtario contributor Matt McIntosh talks with Chris Snip, crop sales specialist with Agris Co-operative, about waterhemp in Essex County, wider herbicide management concerns – […] Read more


Waterhemp is a cross-pollinating species, which improves its ability to develop herbicide resistance.

Weed of the week: Waterhemp

The challenging weed rapidly develops resistance, so rotating herbicides is critical

Waterhemp can be controlled through a variety of approaches, but identification is often difficult. The weed — a non-native member of the pigweed family first discovered in Lambton County in […] Read more


OMAFRA Weed Management Specialist Kristen Obeid is part of a team collecting leaf tissue from weeds in vegetable crops that could potentially possess resistance to herbicides.

Tracking down resistant weeds

Multiple herbicide-resistant weeds found in vegetable fields

Ontario Ministry of Agriculture, Food and Rural Affairs Weed Management Specialist Kristen Obeid is part of a team entering the fourth year of an initiative — funded through Agriculture and […] Read more