An Introduction to Tomato Grafting with Andy Robie

April 1, 2014

Author: Neighborhood Farm Initiative

Category: Growing Knowledge

Tomato season is upon us and we know that once you start grafting, you might never settle for less! Grafted tomatoes combine the best of both worlds: high production and disease resistance—even on the fussiest varieties!

Last week, local expert Andy Robie, was kind enough to share his wisdom during our Tomato Grafting 101 workshop (Click here for the video re-cap!). As a medical student, he raised his first tomato plants and diagnosed his first case of blossom end rot on a fire escape in Cincinnati. He is now a four season vegetable gardener at home in Takoma, DC and at the Blair Road Community Garden.IMAG0567

For those of you that don’t know, “grafting” refers to the removal of the top [scion] of a tomato seedling followed by its attachment to a specialized hybrid rootstock grown specifically for its disease resistance and ability to produce in high quantity. The rootstock provides protection from several tomato viruses and diseases, so that you can grow [lots of] yummy tomatoes!

Andy Robie’s Fool-Proof Tomato Tips:

  • Select a scion and a root stock plant with approximately equal stem diameters – try not to water your seedlings for about 24 hours before grafting
  • Wash your hands and make sure your grafting area is clean
  • Cut the stem of the rootstock seedling about 1/4” below the cotyledon (lower pair of simple leaves) at about 45 degrees
  • Cut the stem of the scion below the cotyledon at about 45 degrees
  • Match up the two cut ends and join with a grafting clip



  • Care in the first week after grafting aimed at reducing water stress while the plants’ vascular systems join together is crucial to your graft’s success
  • Place grafts immediately into a “healing chamber” (a clean seed starting tray with another seed starting tray used as a lid works) and let them rest
  • The environment in the healing chamber must be dark and humid (~90% humidity) – these conditions decrease water loss through transpiration.
  • Avoid anything that will displace the graft – breeze, unnecessary movement, an errant healing chamber lid.
  • Gently mist twice a day or leave a damp paper towel in the chamber to increase humidity.  If misting, be careful not to knock the scions off the rootstock
  • No watering until the grafts begin to heal (about 2 days) – water taken up by the rootstock can actually knock the scion off the top
  • After grafts heal (2-4 days, wilting resolves) gradually reintroduce them to indirect sunlight of fluorescent light and normal humidity levels (using a clear lid cracked open for a day or two then removed works for this)
  • About 7 days after grafting, plants may be reintroduced to normal light


Want to learn more about grafting and Andy Robie’s seed-starting soil mix? Click here for all the details!


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