Workshops: Tomato Grafting Techniques for Soil-Borne Disease Resistance

Tomato and watermelon can be significantly impacted by Verticillium wilt, a soil-borne disease common throughout Washington. Symptoms impact plants later in development after most production costs have been incurred, resulting in a 25-100% crop loss in some years. Grafting vegetable crops onto resistant rootstock is a cultural control method that provides an organic and sustainable alternative to soil fumigation. Grafting has been used successfully in Asia for nearly 100 years, but is only now being adopted in the U.S. Based on work done in our CSANR Project 76 “Vegetable grafting for Verticillium dahliae resistance” (Miles and Inglis 2010-11), we have developed extension publications outlining low-cost grafting techniques and set-up of greenhouse healing chambers for tomatoes. This new proposed project will: 1.) develop fact sheets for watermelon grafting techniques, and 2.) extend information gained regarding tomato grafting to farmers, plant propagators, and Master Gardeners. Workshop participants will be trained so they can successfully propagate their own grafted vegetables. Master Gardeners will pass along their knowledge of grafting techniques and equipment to clients, including cooperators from high school garden projects, demonstration gardens, and home and community gardens.

Grant Information

  • Project ID: 106
  • Project Status: Complete




Miles, C, L. Hesnault, S. Johnson, and P. Kreider. 2012. Vegetable Grafting: Watermelon. Washington State University Extension Publication FS100E. 7 p. .

Miles, C., S. Johnson, and D. Inglis. 2012. Managing Verticillium wilt on eggplant through grafting, and graft survival in healing chambers. Proceedings International Research Conference on Methyl Bromide Alternatives and Emissions Reduction, November 8, Maitland, Florida, p. 67.

Miles, C. 2013. Grafting Vegetables. Added new information to this website; 4,560 visits in 2012.

Additional Funds Leveraged

CAHNRS EMERGING RESEARCH ISSUES – Grafting watermelon: A new sustainable management practice for soilborne disease and a new value-added enterprise for Washington, $49,938 received for 2013
CSANR – On-line Training Module for Grafting Vegetable Transplants, $4,908 to be received for 2013
NARF – Screening Watermelon Rootstock for Tolerance to Verticillium Wilt, $ 2,675 r received for 2013
WSCPR – Identifying Watermelon Rootstock with Resistance to Verticillium Wilt, $5,000 requested for 2013 $3,000 funded 12/14/12
WSDA – Using grafted watermelon to manage Verticillium Wilt in Washington, $50,000 requested for 2013, this proposal was not funded


Short-Term: Workshop participants were made aware of vegetable grafting as a method to control soil borne disease such as Verticillium wilt (Verticillum dahliae) in tomato, eggplant, and watermelon, the timing needed to coordinate seeding of rootstock and scion varieties to ensure
stem compatibility, and the construction and management of a healing chamber. Participants successfully grafted tomato, eggplant and watermelon plants, and acquired the ability to instruct staff and clients in these techniques. We further refined grafting methods for
watermelon and published a watermelon grafting fact sheet.

Intermediate-Term: Staff and clients trained by workshop participants will be able to practice and master the hands-on techniques of tomato grafting, and develop a greater understanding of the reasons behind its use. Trainee participants will have the resources to carry out a successful
program of tomato grafting in their operations and programs, including commercial vegetable farms, demonstration gardens, and community gardens as well as home gardens. An improved success rate for grafted watermelon will improve overall productivity and encourage further adoption of this pest management technique.

Long-Term: Use of grafting to control soil borne diseases of tomato and watermelon will become a well known practice for commercial agricultural professionals and the general clientele of gardeners at the community and home level. Where applicable, grafting techniques will be extended to other crops such as cucumbers.