Pasture Weed Control with Juglone (Black Walnut) Spray

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2014: $7,336.00
Projected End Date: 12/31/2014
Region: North Central
State: Missouri
Project Coordinator:
Serena Cochrane
Stuart Farm, LLC

Annual Reports


  • Agronomic: general hay and forage crops
  • Nuts: walnuts


  • Animal Production: pasture renovation
  • Crop Production: application rate management
  • Pest Management: allelopathy, precision herbicide use
  • Production Systems: organic agriculture, transitioning to organic

    Proposal summary:

    The current project will test the effectiveness of an herbicide made from Black Walnut Hulls (Juglone) to control cocklebur, thistle, nightshades, and multiflora rose in livestock pastures as an alternative to synthetic herbicides. 

    We consciously choose not to use synthetic herbicides on our pastures and as a result, I hand pick certain pasture weeds. Collecting and disposing of the plants is time consuming and robs the soil of valuable plant matter. After noticing no multiflora rose growing in our Black Walnut grove, and knowing the growth suppression (allelopathic) effect of Juglone in the ground, I thought perhaps a spray made from the soaked walnut hulls (which contains a high level of Juglone) could provide a simple herbicide. If such a spray does work, it could replace a synthetic herbicide with one that relies on its own natural allelopathic abilities, is easy to make, uses what most consider a waste product, and is inexpensive. This would be an excellent alternative for farmers who want to use a more sustainable and natural method of weed control.

    Project objectives from proposal:

    The first goal of the project is to successfully extract Juglone from the walnut hulls. The hulls will be soaked in two mediums-water and vinegar. Soaking times will vary to determine if extra soaking time makes a stronger extract.

    The second goal is to determine which, if any, of the concentrations will effectively eliminate the targeted pasture weeds. 

    Data collected for each concentration level will be: number and type of plants sprayed; stage of growth; application rate (spray per plant and number of days sprayed); effects of the spray on the test plant, i.e. wilted leaves, death, burns, etc.; if a plant does die, how long and how many applications did it take; effects on surrounding plants; min and max temperatures; rainfall. All data will be complied and bar graphs generated to display data in an easy-to-read format for comparisons among concentrations. Photos of treated plants will be taken throughout the project for comparisons.

    Success of this project will be determined if the target plants are successfully killed and/or noticeable debilitated and if the Juglone extract does not negatively affect pasture growth.


    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.