UNIVERSITY OF CALIFORNIA COOPERATIVE EXTENSION

UC MASTER GARDENER PROGRAM OF SAN LUIS OBISPO COUNTY

The UC Master Gardener Program is a public service and outreach program under the University of California Division of Agriculture and Natural Resources (UC ANR), administered locally by participating UC Cooperative Extension offices (UCCE). Our mission is to extend research based

knowledge and information on home horticulture, pest management, and sustainable landscape practices to the residents of California.

TOMATOES: GRAFTING MIKE ZIGELMAN, UC Master Gardener

Tomato gardeners searching for new and great tasting tomato varieties may be hampered by limitations of their garden, namely disease, poor soil, salinity or temperature extremes. There is a possible solution to these problems: grafted tomatoes.

Advantages of Grafted Tomato Plants

• Increased plant vigor and tomato yield • Disease resistance to common local diseases like Verticillium Wilt and Tomato Spotted

Wilt Virus • Tolerance to greater variations in temperature

What is a Grafted Tomato • A grafted tomato plant is created by combining a preferred variety to a hardy

rootstock. The rootstock refers to the roots and lower portion of the plant while the fruiting tomato variety, the scion, is the top portion of the plant

• The rootstock is chosen for its superior and specific growth characteristics and the scion is chosen for its desirable fruit qualities

Home gardener considerations

• Evaluate cost of purchased grafted plants vs. grafting supplies vs. hobby value • Consider the number of grafted plants and varieties desired. •

Basic supplies • Rootstock seeds and scion seeds • Growing cells/flats and clean germination mix, bleach for cleaning flat, heating mat • Grafting clips, razor blades • Covered growing chamber with adjustable ventilation, thermometer, humidity meter

and misting bottle •

Grafting tips • Timing of planting: plant scions first then rootstock. The goal is for the stems of

scions and rootstock plants to be same size at time of grafting • Sanitation: Use high quality seeds to prevent seed borne diseases. Sanitize

workspace and wash hands when working with seedlings • Change grafting blades frequently to maintain sharp edges and achieve clean cuts

TYPE ALSO KNOWN AS IMAGE ADVANTAGES DISADVANTAGES

SIDE GRAFT Side by side

High success rate and

can use larger plants

Slower, more difficult

technique

CLEFT GRAFT Wedge graft

Graft site more secure

than top grafting

Technique needs more time

TOP GRAFT

Splice graft tube graft

Easy to learn and do

Requires grafting clips

Post Graft Care

• Maintain plants in dark for 3-4 days • 80-85˚F at 80% humidity or greater and mist as necessary • Remove and discard dead or dying plants to avoid contamination of remaining plants • Harden off after 3-4 days by gradually decreasing humidity and increasing light.

Return to “healing” conditions if necessary • Transplant to larger containers or cells as vigorous growth resumes and graft appears

tight

Planting in the Garden • Make sure the graft union is well above ground level. Gardeners often plant tomatoes

deep but this cannot be done with grafted tomato plants. The graft union must be kept above ground.

• Expect a two week delay in harvest time with grafted tomatoes.

References: Grafting Tomato Plants. 2009. Video. Ohio State University. https://www.youtube.com/watch?v=tHnOYcI6B44

Guan, Wejing and Steve Hallett. 2016. Vegetable Grafting: Techniques For Tomato Grafting. PDF. Purdue Extension. https://extension.purdue.edu/extmedia/HO/HO-260-W.pdf

Heinz, Matthew and Monicah Weiganjo, et al. Tomato Grafting Guide: Preparing Grafted Tomato Plants Using The Cleft Graft Method. PDF. UC Davis. http://horticulture.ucdavis.edu/main/Deliverables/Kleinhenz/tomato_grafting_guide.pdf

How To Graft Greenhouse Tomatoes. 2011. Video. University of Vermont. https://www.youtube.com/watch?v=WSwTCwlhFgo

Hu, Bizhen and Stephanie Short., et al. A Pictorial Guide To The Cleft And Splice Graft Methods For Tomato And Pepper. 3rd ed. Ohio State University Extension. http://u.osu.edu/vegprolab/grafting-guide/grafting-guide-request/

Johnson, Sacha and Patti Kreider. 2011. Vegetable Grafting: Eggplants And Tomatoes. PDF. WSU Extension. http://extension.wsu.edu/benton-franklin/wp-content/uploads/sites/27/2014/04/Grafting-Eggplants-and-Tomatoes-FS052E.pdf

UC MASTER GARDENERS 2156 SIERRA WAY, SUITE C SAN LUIS OBISPO, CA 93401 email: anrmgslo@ucanr.edu

GARDENING QUESTIONS? ASK THE MASTER GARDENERS AT HELPLINE: 805-781-5939

Website: Master Gardeners San Luis Obispo

Availability on VMS > Documents/Presentations > INFORMATIONAL DOCUMENTS > TOMATOES: GRAFTING History Original: 2/28/17 Revised: month/year: