Grafting Vegetables
Introduction
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 in the 1990’s and growers continue to become more aware of its attributes and potential. At Washington State University, we began vegetable grafting in 2009 with three crops: tomato, eggplant and watermelon.
Advantages
- 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.
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 (Figure 2).


Research Highlights
Advances have been achieved by our WSU vegetable grafting research team in the splice-grafting method for watermelon, where both the cotyledons are removed from the rootstock, which eliminates rootstock-regrowth.
Research Publications
Fact Sheets
- Vegetable Grafting: The Healing Chamber (PDF). WSU Extension Fact Sheet FS051E 3 pages. Published October 2011, reviewed July 2016.
- Vegetable Grafting: Watermelon (PDF). WSU Extension Fact Sheet FS100E 7 pages. Published January 2013, reviewed June 2016.
- Vegetable Grafting: Eggplant and Tomatoes (PDF). WSU Extension Publication FS052E.
- Verticillium wilt on watermelon. WSU Vegetable Horticulture Program Fact Sheet. Published September 2018, reviewed May 2026.
- Watermelon splice grafting. WSU Vegetable Horticulture Program Fact Sheet. Published April 2021, reviewed May 2026.
En Español
- Injertos Hortícolas: SandÍa (PDF). Hoja de datos de la Extensión, Universidad Estatal de Washington FS100ES. 7 páginas. Publicado enero 2014.
- Injerto de Verduras: Berenjenas y Tomates (PDF). Hoja informativa de la Universided Estatal de Washington FS052ES. 4 páginas. Publicado Agosto 2013.
- Injerto Illustrado/Grafting Illustrated (PDF) – handout includes illustrations of grafting techniques with key words in Spanish.
Video
- Watermelon Grafting Methods (Youtube Video). This video includes WSU’s recent research advances in grafting watermelon using the splice grafting method.
Research Articles: Grafting Methods
- Dabirian, S., and C. Miles. 2017. Antitranspirant application increases grafting success of watermelon. HortTechnology 27:494–501.
- Dabirian, S., and C. Miles. 2017. Increasing survival of grafted watermelon seedlings using a sucrose application. HortScience 52:579–583. 2017.
- Devi, P. and C.A. Miles. 2021. Increasing survival and efficacy of splice-grafted watermelon using sucrose and antitranspirant. Acta Hortic. 1302:73-78.
- Devi, P., S. Lukas, and C.A. Miles. 2020. Advances in watermelon grafting to increase efficiency and automation. Horticulturae 6(4):88.
Research Articles: Healing Chamber
- Buajaila, F., P. Devi and C. Miles. 2018. Effect of environment on survival of eggplant, pepper and eggplant in a small-scale healing chamber. HortTechology 28(5):668–675.
- Johnson, S. and C. A. Miles. 2011. Effect of healing chamber design on the survival of grafted eggplant, watermelon, and tomato. HortTechnology 21: 752–758.
Research Articles: Grafting Effect on Fruit Quality
- Devi, P., P. Perkins-Veazie, and C.A. Miles. 2020. Impact of grafting on watermelon fruit maturity and quality. Horticulturae 6(4):97.
- Devi, P., S. Lukas and C. Miles. 2020. Fruit maturity and quality of splice-grafted and one-cotyledon grafted watermelon. HortScience 55(7):1090–1098.
Research Articles: Grafting for Verticillium wilt Disease Control
- Attavar, A., L. Tymon, P. Perkins-Veazie, and C.A. Miles. 2020. Cucurbitaceae germplasm resistance to verticillium wilt and grafting compatibility with watermelon. HortScience 55:141–148.
- Attavar, A.S. and C.A. Miles. 2021. Resistance of eggplant grafted onto commercial Solanaceae rootstocks against Verticillium dahliae. Acta Hortic. 1302:147–154.
- Attavar, A.S. and C.A. Miles. 2021. Screening World Vegetable Center eggplant and pepper rootstocks for resistance to Verticillium wilt. Acta Hortic.1302:155–162.
- Buller, S. D. Inglis and C. Miles. 2013. Plant growth, fruit yield and quality, and tolerance to Verticillium wilt of grafted watermelon and tomato in field production in the Pacific Northwest. HortSci. 48:1003–1009.
- Dabirian, S., D. Inglis and C. Miles. 2017. Grafting watermelon and using plastic mulch to control Verticillium wilt caused by Verticillium dahliae in Washington. HortScience 52:349–356. 2017.
- Devi, P., L. Tymon, A. Keinath and C. Miles. 2021. Progress in grafting watermelon to manage Verticillium wilt. Plant Pathology 767–777.
- Devi, P., P. Perkins-Veazie, and C.A. Miles. 2020. Rootstock and plastic mulch effect on watermelon flowering and fruit maturity in a Verticillium dahliae infested field. HortScience 55(9):1438–1445.
- Johnson, S., C. Miles, and D.A. Inglis. 2013. First report of Verticillium wilt caused by V. dahliae on grafted Solanum aethiopicum in Washington. Plant Dis. 97:840.
- Johnson, S., D.A. Inglis, and C. Miles. 2013. Grafting effects on eggplant growth, yield and verticillium wilt incidence. Intl. J. Veg. Sci.
- Miles, C., J. Wimer and D. Inglis. 2015. Grafting eggplant and tomato for Verticillium wilt resistance. ActaHortic. 1086:113–117.
- Wimer, J., D. Inglis and C. Miles. 2015. Evaluating grafted watermelon for Verticillium wilt severity, yield and fruit quality in Washington State. HortScience 50(9):1332–1337.
- Wimer, J., D. Inglis and C. Miles. 2015. Field and greenhouse evaluation of cucurbit rootstocks to improve Verticillium resistance for grafted watermelon. HortScience 50(11):1625–1630.
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