Worst Weeds, Ranked

Weeds in a field
WSSA asked weed scientist to identify the most troublesome weeds as well as the most common weeds in their state. They considered herbicide resistance, frequency and crop affected by the weeds while making their rankings.

While palmer is only listed as the most troublesome weed in cotton, it’s ranked first overall because most respondents listed it as problematic.

Most Troublesome
1. Palmer Amaranth
2. Common Lambsquarters
3. Horseweed (Marestail)
4. Morning Glory (ivyleaf, pitted, tall)
5. Waterhemp (tall, common)
6. Nutsedge (yellow, purple)
7. Kochia
8. Common Ragweed
9. Giant Ragweed
10. Nightshade (eastern black, hairy) 

Most Common
1. Common Lambsquarters
2. Foxtail (giant, green, yellow)
3. Morning Glory (ivyleaf, pitted, tall)
4. Palmer Amaranth
5. Redroot Pigweed
6. Waterhemp (tall, common)
7. Horseweed (Marestail)
8. Common Ragweed
9. Barnyardgrass
10. Velvetleaf 


Broadleaf Crop

Most Troublesome Weed

Most Common Weed


Canada Thistle




Wild Oat


Palmer Amaranth

Morning Glory

Fruit and nuts

Field Bindweed

Horseweed (Marestail)



Palmer Amaranth


Common Lambsquarters

Common Lambsquarters


Horseweed, Waterhemp


Sugar Beets

Common Lambsquarters

Common Lambsquarters



Common Lambsquarters


Does this match what you consider the worst weeds in your fields? Let us know!

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