interrow weeder

Weed Science

Weed identification and management resources to help you reduce the impact of these unwanted plants in fields, gardens, landscapes and ecosystems.

Weed topics

Weed identification

Identify the competition

Ecological management

Weed ecology and organic management

Herbicides

Resources on the proper use of chemical management options.

Weed profiles

Learn weeds' weaknesses

About our programs

Weed science labs and programs at Cornell

New and improved!

2nd edition of Weeds of the Northeast now available

This fully updated second edition of the best-selling Weeds of the Northeast provides lavish illustrations for ready identification of more than 500 common and economically important weeds in the Northeast and in the Upper Midwest and Mid-Atlantic states. 

This new edition covers the region south to North Carolina, north to Maine and southern Canada, and west to Wisconsin. This practical guide includes descriptions and photos of floral and vegetative characteristics, giving anyone who works with plants the ability to identify weeds before they flower.

Don't miss 'Chats in the Stacks' with author Toni DiTommaso April 20, 2023 at 4 p.m. in Mann Library 160 and via Zoom. View event.

weeds of the northeeast cover

Weed science news

ryan maher in the field wearing cornell weed science tee shirt

News

New organic leadership for Cornell AES
Ryan Maher, a research, extension, and soil health specialist for the Cornell Small Farms Program since 2013, has assumed a new leadership position as Organic Coordinator for the Cornell University Agricultural Experiment Station (Cornell AES)...
  • Cornell University Agricultural Experiment Station
  • School of Integrative Plant Science
  • Horticulture Section
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Field Note

Multimedia

Many little hammers: tools for weed management in soybeans
For the past two years, Annika Rowland, a graduate student in the Sustainable Cropping Systems Lab at Cornell University, has been studying how to manage weeds in soybean production without the use of herbicides or cultivation. Rowland’s...
  • Cornell University Agricultural Experiment Station
  • School of Integrative Plant Science
  • Soil and Crop Sciences Section
aleah butler jones in front of poster

News

Researchers, grad students shine at weed science meetings
Cornell weed science researchers and graduate students brought home numerous awards at the joint annual meeting of two major societies January 30 in Arlington, Va. From the Northeastern Weed Science Society (NEWSS): Lynn Sosnoskie, assistant...
  • School of Integrative Plant Science
  • Horticulture Section
  • Soil and Crop Sciences Section
Doctoral students Aleah Butler-Jones '19, left, and Maria Gannett, M.S. '16 practice with other Cornell graduate students at a hotel parking lot the night before the weed competition.

News

Undergrads win Northeastern Weed Science Society contest

Cornell’s undergraduate Weed Team won first place, while Megan Wittmeyer ’22 earned a top individual award, at the Northeastern Weed Science Society Collegiate Weed Science Contest.

  • Cornell AgriTech
  • School of Integrative Plant Science
  • Soil and Crop Sciences Section
Doctoral student Maria Gannett practices a walking cadence with a sprayer full of water.

News

Get off my awn: Cornell Weed Team to compete in Ontario

For the students on the Cornell Weed Team, who face endless marijuana wisecracks from nonscientists, competing in the Northeastern Weed Science Society’s tournament in Guelph is no joke.

  • Cornell AgriTech
  • Cornell Atkinson
  • School of Integrative Plant Science

Disclaimer

Disclaimer: Please read the pesticide label prior to use. The information contained at this web site is not a substitute for a pesticide label. Trade names used herein are for convenience only; no endorsement of products is intended, nor is criticism of unnamed products implied.