How to Graft Tomato Rootstocks

Sterilize all work surfaces and tools by cleaning with a solution of 1 part bleach to 10 parts water. Wash your hands with antibacterial soap. Clean your hands frequently during grafting with antibacterial gel. You may wear gloves, but they can interfere with dexterity. Change your gloves frequently if working with a large number of seedlings.

Use seedlings with four to five leaves. Inspect the tomato rootstock and scion plants and choose two with the same diameter stems. It is very important that the diameters be the same so the graft surfaces fit exactly onto one another.

Cut the scion seedling above the seed leaves and cut the rootstock seedling below the seed leaves with the razor blade. Prune all but the small top leaf from the scion plant to prevent moisture loss.

Place the scion against the rootstock stem and move them until you find a place where the diameters match. Make a single cut with the razor blade through both stems at approximately a 30-degree angle.

Place the tube clip over the rootstock stem below the cut end. Match the cut on the scion to the cut on the rootstock and gently pull the tube clip up until it joins the two cut ends.

Spray your seedlings with water after each seedling is grafted to prevent wilting. When all seedlings are grafted, place them in a healing chamber with a sealed bottom that holds water. A simple healing chamber can be constructed of a frame covered by clear plastic sheeting. The frame should hold the plastic sheeting at least a foot above the seedlings. Provide shade with shade cloth or by placing them into a shady or low-light location.

Water the seedlings in the healing chamber from the bottom and maintain humidity at 85 to 90 percent for one week. Harden off your plants after one week by gradually exposing them to more sunlight and increasing the air flow over three to four days. Decrease the humidity gradually until the grafts have fully formed. The time for graft formation varies from 10 days to 2 weeks, depending on the varieties and conditions.

Fertilize the seedlings after two weeks with a one-fourth strength liquid tomato fertilizer. Increase the strength gradually every few days over the next two weeks until they are being fertilized at full strength.