Weed Identification Series, Waterhemp and Palmer Amaranth

Mark Renz UW Madison Associate Professor and Extension Specialist

Concern about the continued spread of waterhemp and Palmer amaranth exist in Wisconsin. While invasion of these species has been much higher in adjacent states, populations are expanding in Wisconsin and we likely will be impacted from these species in the future. However identification can be challenging as they look similar, especially when vegetative.

To assist with identification NPM/IPM (Roger Schmidt and Mimi Broeske) we have created a vegetative identification video and factsheets.

The video highlights a two-step process to differentiate waterhemp and Palmer from other common pigweed species (redroot, smooth, spiny) found in Wisconsin.

We have also created weed identification factsheets for Palmer and waterhemp to aid in further identification.

It is our hope that this information will assist in early detection of new populations in Wisconsin and encourage management before they are spread.

We will be encouraging reporting of pigweed populations in future weeks to better understand their distribution and what factors are driving spread. Be on the lookout for more information. To view the identification sheets click here…

Palmer Amaranth ID
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Waterhemp ID
262.9 KB