Grafting Vegetables


Vegetable grafting is a centuries-old technique utilized in Asia to improve plant production, reduce disease susceptibility, and increase soil utilization. Vegetable grafting was introduced in the United States almost 30 years ago and growers are becoming more aware of its attributes and potential. At Washington State University, we began vegetable grafting in 2009 with three crops: tomato, eggplant and watermelon.

Research Highlights

Recent adavances have been achieved by WSU vegetable grafting research team in Splice-grafting method for watermelon, where both the cotyledons are removed from the rootstock, that can elimiate rootstock-regrowth issue.


  •  Resistance towards soil borne diseases verticillium wilt (figure 1), fusarium wilt, root nematode etc.
  • Reduce or eliminate the use of pesticides
  • Increased vigor and yield
  • Tolerance to environmental stress
  • Better water and nutrient uptake

Our research projects involve how to graft watermelon and the use of grafted watermelon as a biological disease management practice for verticillium wilt. Rootstock regrowth and labor are the major concerns with one cotyledon grafting method, which is the most commonly used method for watermelon. Our research studies have advanced grafting watermelon using the splice grafting method where both cotyledons are removed from the rootstock, thereby attaining affordable grafted watermelon transplants to expand utilization.

Comparing grafted and non-grafted watermelon plants in a field
Figure 1. Non-grafted ‘Fascination’ watermelon plant with verticillium wilt, and (B) grafted ‘Fascination’ watermelon plant without verticillium wilt; photos taken on the same day in adjacent areas of the same field, 22 September 2017.

Melon Grafting

Melons grown in cooler temperature may experience sudden vine wilt, which adversely affects production. Our research results have shown that grafting prevents sudden vine wilt under cool soil conditions producing marketable melons in Pacific Northwest.

Grafting melons in a field
Figure 2. Sudden vine wilt in nongrafted ‘Goddess’ cantaloupe on the left (A), and ‘Goddess’ grafted onto ‘Super Shintosa’ on the right (B) in Mount Vernon NWREC, 2020.

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