Determining if Comfrey Fermented Plant Juice is a viable alternative to traditional purchased fertilizers

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2022: $24,963.00
Projected End Date: 03/31/2023
Host Institution Award ID: G370-22-W8613
Grant Recipient: Rainshadow Organics
Region: Western
State: Oregon
Principal Investigator:
Sarahlee Lawrence
Rainshadow Organics


  • Vegetables: peppers
  • Additional Plants: native plants


  • Crop Production: nutrient cycling
  • Education and Training: farmer to farmer, on-farm/ranch research

    Proposal summary:

    The cost of fertilizers is a significant factor in an organic farmers’ budget.  Quality fertilizers may be difficult to source and ship to the farm. Producing on farm fertility is a cheaper and more sustainable alternative, compost being one example. At Rainshadow Organics we have developed a method using comfrey fermented plant juice (CFPJ) that we believe could be an alternative to traditional fertilizers.  Our main questions are how safe and effective is the CFPJ, and is it feasible for a farmer to produce systematically?  First, we plan to use CFPJ as we have the past two seasons on our 25-acre field as a demonstration plot.  Second, we plan to implement experimental plots in our hoophouses.  The experimental plots will be used to collect data regarding crop yields, in situ observation, nutrient density of crops, soil biology, and soil nutrients.  We will also compare the cost of CFPJ production with purchasing traditional fertilizer.  The benefits of this research are numerous.  A sustainable farm system must be a closed loop, this is a method to move closer to that ideal.  Traditional fertilizer is also expensive; this research provides an alternative that would make organic farming more economically viable. This research is widely applicable as comfrey grows abundantly in a variety of climates. To reach other growers and farmers we plan to provide farm tours/field days to interested growers and community members, submit our findings to the Central Oregon Ag-newsletter, and present our findings to the Quivira Coalition.

    Project objectives from proposal:


    Research objectives:

    1. Determine if Comfrey (Symphytum officinale) Fermented Plant Juice (CFPJ) is an effective alternative to traditional fertilizer with regard to crop yield, plant health, and soil health.
    2. Determine if CFPJ is safe to use and does not contain unsafe or pathogenic bacteria.
    3. Show the cost comparison of the production and application of CFPJ versus traditional purchased fertilizer.  

    Education objectives:

    1. Provide a framework for farmers to safely produce their own on-farm fertility using comfrey.
    2. Create space for community to learn about the innovative research their farmers are conducting to create a healthier local food system.
    3. Work with The Quivira Coalition to reach their network of ranchers, farmers, researchers, teachers, government and Tribal agency staff in the West.
    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.